# Patent

## Title
Newcastle disease virus vectored avian vaccines

## Abstract

The present invention encompasses engineered Newcastle Disease Virus (NDV) vaccines or compositions. The vaccine or composition may be a recombinant vaccine. The invention also encompasses recombinant vectors encoding and expressing avian pathogen antigens, more specifically avian influenza proteins, epitopes or immunogens. Such vaccines or compositions can be used to protect animals, in particular avian, against disease.

## Background
INCORPORATION BY REFERENCE
This application is a continuation of U.S. application Ser. No. 12/753,597 filed on Apr. 2, 2010, which claims benefit of U.S. provisional application Ser. No. 61/166,481 filed Apr. 3, 2009.


FIELD OF THE INVENTION
The present invention encompasses NDV-vectored avian vaccines or compositions, in particular avian influenza vaccines. The vaccine may be an engineered avian vaccine.
BACKGROUND OF THE INVENTION
Several studies in recent years have highlighted the potential of Newcastle disease virus (NDV) to be used as a vaccine vector for avian diseases (Krishnamurthy et al., Virology 278, 168-182, 2000; Huang et al., J. Gen. Virol. 82, 1729-1736, 2001; Nakaya et al., J. Virol. 75, 11868-11873, 2001; Park et al. PNAS 103, 8203-8208, 2006; Veits et al PNAS 103, 8197-8202, 2006; Ge et al. J. Virol. 81, 150-158, 2007; Romer-Oberdorfer et al. Vaccine 26, 2307-2313, 2008).
NDV belongs to the Paramyxovirinae family and the Avulavirus genus. NDV replicates in respiratory and gastrointestinal tracts, in the oviduct, and for some isolates, in the nerve system. The transmission is aerogenic and by oral and fecal routes. NDV causes a highly contagious and fatal disease affecting all species of birds, and can infect some mammalian species. The disease can vary from clinically unapparent to highly virulent forms, depending on the virus strain and the host species. The continuous spectrum of virulence displayed by NDV strains enabled the grouping of them into three different pathotypes: lentogenic, mesogenic, and velogenic (Alexander, D. J., Diseases of Poultry, Iowa State Uni. Press, Ames Iowa, 541-569, 1997). Lentogenic strains do not usually cause disease in adult chickens and are widely used as live vaccines in poultry industries in the United States and other countries. Viruses of intermediate virulence are termed mesogenic, while viruses that cause high mortality are termed velogenic. The disease has a worldwide distribution and remains a constant major threat to commercial poultry production.
The NDV genome is a non-segmented negative strand of RNA of approximately 15 kb. The genomic RNA contains six genes that encode the following proteins in the order of: the nucleocapsid protein (NP), phosphoprotein (P), matrix protein (M), fusion protein (F), haemagglutinin-neuramimidase (HN) and large polymerase protein (L). Two additional proteins, V and W, of unknown function are produced by RNA editing during P gene transcription (Steward et al., 1993, Journal of General Virology 74:2539-2547).
The development of methods to recover non-segmented negative RNA viruses entirely from cloned cDNA, established in recent years, opened up the possibility of genetically manipulating this virus group, including NDV (Conzelmann, K. K., Ann. Rev. Genet. 32, 123-162, 1998; Roberts and Rose, Virology 247, 1-6, 1998). This unique molecular genetic methodology, termed “reverse genetics,” provides a means not only to investigate the functions of various virus-encoded genes (Palese et al., PNAS 93, 11354-11358, 1996; Nagai, Y., Rev. Med. Virol. 9, 83-99, 1999) but also to allow the use of these viruses to express heterologous genes (Bukreyev et al., J. Virol. 70, 6634-6641, 1996; Mebatsion et al., PNAS 93, 7310-7314, 1996; Schnell et al., PNAS 93, 11359-11365, 1996; Hasan et al., J. Gen. Virol. 78, 2813-2820, 1997; He et al., Virology 237, 249-260, 1997; Sakai et al., FEBS Lett. 45, 221-226, 1999). This provides a new method of generating improved vaccines and vaccine vectors.
The recovery systems from cloned cDNA, based on a lentogenic vaccine strain (LaSota) of NDV, were reported simultaneously by two independent groups in 1999 (Peeters et al., 1999; Romer-Oberdorfer et al., 1999). In the first reported system, the full-length NDV cDNA from LaSota strain (ATCC-VR699) was assembled in pOLTV5 transcription vector containing a T7 DNA-dependent-RNA polymerase promoter. Individual clones of the NDV transcriptase complex (NP, P, and L) were cloned in a eukaryotic expression vector. The cotransfection protocol generated several infective centers in infected monolayers (Peeters et al., J. Virol. 73, 5001-5009, 1999). The second system reported for recovery of a lentogenic NDV from cloned cDNA essentially used the same strategy of assembling the full-length antigenomic expression plasmid and support plasmids (Romer-Oberdorfer et al., Journal of General Virology, 80, 2987-2995, 1999). Other systems were developed recently to recover a lentogenic Hitchner B1 (Nakaya et al., 2001) or LaSota strain of NDV (Huang et al., 2001). The only system available for the recovery of recombinant mesogenic NDV was described by Krishnamurthy et al. (2000). This system utilized the vaccinia virus recombinant (MVA) and HEP-2 cells for transfection. The full length clone of the mesogenic strain Beaudette C and the support plasmids (N, P, and L) from the same strain were used for transfection. An additional transcriptional unit encoding the CAT reporter gene was placed between the HN and L genes. The growth of the rNDV expressing the CAT gene was delayed and the virus was attenuated. The CAT reporter gene was stably expressed for several passages in cell culture.
Avian influenza (AIV), sometimes called avian flu, and commonly recognized as bird flu refers to influenza caused by influenza viruses adapted to birds. AIV is a segmented, single-strand, negative sense RNA virus belonging to the family of Orthomyxoviridae, and is classified as a type A influenza virus. Type A virus is the most frequent cause of animal and human influenza. This type occurs in numerous strains or subtypes that are differentiated mainly on the basis of two surface lipid-enveloped membrane proteins, hemagglutinin (HA) and neuraminidase (NA). HA, facilitates entry of the virus into host cells, and NA assists in the release of progeny virus from infected cells (de Jong et al., J Clin Virol. 35(1):2-13, 2006). Influenza type A viruses are divided into subtypes based on their specific HA and NA content. There are 16 different HA subtypes, and 9 different NA subtypes. Many different combinations of HA and NA proteins are possible. Subtypes of influenza A virus are named according to their HA and NA surface proteins. For example, an “H7N2 virus” designates an influenza A subtype that has an HA protein of the H7 subtype and an NA protein from the N2 subtype. Similarly an “H5N1” virus has an HA of the H5 subtype and an NA from the N1 subtype. The H5N1 subtype has specifically been associated with recent outbreaks in Asia, Russia, the Middle East, Europe and Africa (Olsen et al., Science 21; 312(5772):384-8, 2006).
Influenza A viruses can infect humans, pigs, horses, seals, whales, poultry, cats, dogs, ferrets and other animals, but wild birds are their natural host. Aquatic birds constitute the main influenza reservoir from which virus lineages evolved and adapted to their host, e.g., human, swine and equine influenza. Host specificity is not absolute and cross-species transmission may occur as illustrated by the ability of highly pathogenic avian influenza (HPAI) H5N1 subtype to infect human, feline, canine and porcine species.
The highly pathogenic Influenza A virus subtype H5N1 virus is an emerging avian influenza virus of global concern as a potential pandemic threat. H5N1 has killed millions of poultry in a growing number of countries throughout Asia, Europe and Africa. Unlike type B influenza, type A influenza undergoes antigenic shift (at least two different strains of virus combine to form a new subtype) and epidemiologists, infectious disease investigators, and other health experts are acutely concerned that the co-existence of human flu viruses and avian flu viruses (especially H5N1) may provide an opportunity for genetic material to be exchanged between species-specific viruses, possibly creating a new virulent influenza strain that is easily transmissible and lethal to humans (Food Safety Research Information Office. “A Focus on Avian Influenza”. Created May 2006, Updated November 2007).
Since the first H5N1 outbreak occurred in 1997, there has been an increasing number of HPAI H5N1 bird-to-human transmissions leading to clinically severe and fatal human infections. However, because there is a significant species barrier that exists between birds and humans, the virus does not easily cross over to humans. Although millions of birds have become infected with the virus since its discovery, only about 200 humans have died from Avian Flu in Indonesia, Laos, Vietnam, Romania, China, Turkey and Russia combined.
Considering the susceptibility of animals, including humans, to AIV, a means of preventing AIV infection and protecting animals is essential. Accordingly, there is a need for an effective vaccine against influenza.
Citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention.
SUMMARY OF THE INVENTION
The invention is based, in part, on Applicants' discovery that the AIV hemagglutinin gene expressed by the enterotropic AVINEW® strain of Newcastle Disease Virus (NDV) was highly immunogenic in avians.
The present invention relates to an NDV-vectored avian vaccine or composition that may comprise an effective amount of an engineered NDV vector with inherent enteric tropism that harbors and expresses certain avian antigens, more specifically an avian influenza antigen, and a pharmaceutically or veterinarily acceptable carrier, excipient, or vehicle. The enterotropic NDV may be the NDV strain of the AVINEW® modified live vaccine commercialized by Merial Limited.
The avian influenza antigen may be a hemagglutinin. The avian influenza HA antigen may be an HA from the H5 subtype.
The invention also relates to a method of vaccinating an avian comprising administering to the avian an effective amount of a vaccine which may comprise an effective amount of a recombinant NDV vector and a pharmaceutically or veterinarily acceptable carrier, excipient, or vehicle. The administering may be by in ovo, eye drop, spray, drinking water or parenteral (subcutaneous, intramuscular, transdermal) administration.
The invention relates to a method for modifying the genome of Avinew NDV to produce engineered Avinew NDV, wherein the method comprises the introduction into the Avinew NDV genome an isolated polynucleotide in a nonessential region of the Avinew NDV genome. The nonessential region may be an open reading frame encoding a nonessential protein or a non-essential part of an open reading frame; or an untranslated (or non-coding) region located upstream the NP gene, or between two genes (intergenic regions), or downstream from the L gene of the Avinew NDV genome.
The invention further relates to administration of the vaccine or composition using prime-boost protocol. The invention relates to priming the avian with an avian influenza vaccine prior to administration of the vaccine of the present invention that may comprise an effective amount of an engineered NDV vector and a pharmaceutically or veterinarily acceptable carrier, excipient, or vehicle. Alternatively, the invention further relates to priming with the vaccine of the present invention (the engineered NDV vector expressing at least one avian influenza antigen and a pharmaceutically or veterinarily acceptable carrier) prior to administration of an avian influenza vaccine.
The invention further encompasses a kit for performing a method of eliciting or inducing an immune response that may comprise any one of the recombinant influenza immunological compositions or vaccines, or inactivated immunological compositions or vaccines, and instructions for performing the method.
Accordingly, it is an object of the invention to not encompass within the invention any previously known product, process of making the product, or method of using the product such that Applicants reserve the right and hereby disclose a disclaimer of any previously known product, process, or method. It is further noted that the invention does not intend to encompass within the scope of the invention any product, process, or making of the product or method of using the product, which does not meet the written description and enablement requirements of the USPTO (35 U.S.C. §112, first paragraph) or the EPO (Article 83 of the EPC), such that Applicants reserve the right and hereby disclose a disclaimer of any previously described product, process of making the product, or method of using the product.
These and other embodiments are disclosed or are obvious from and encompassed by, the following Detailed Description.



BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description, given by way of example, but not intended to limit the invention solely to the specific embodiments described, may be best understood in conjunction with the accompanying drawings, in which:
FIG. 1A depicts a genetic map of the full length NDV genome;
FIG. 1B depicts a map illustrating the genetic map of two engineered NDV with influenza HA insertion into 2 representative transgene insertion sites into the full length NDV genome;
FIG. 1C is an example of flow diagram of the NDV reverse genetics system, depicting the way to recover engineered NDV infectious particles using NDV reverse genetics.
FIG. 2 depicts a schematic representation of the cloning of the AVINEW whole genome into a transcription plasmid for reverse genetics development and insertion of unique restriction sites (PacI & FseI) allowing easy cloning of transgenes between the P and M genes.
FIG. 3 depicts the plasmid map of the plasmid pIV029.
FIGS. 4a-4o provide the sequence of the insert of the plasmid pIV0291. Italics refer to non AVINEW® sequence and underlined italics refer to an internal PacI-FseI insertion between the P and the M genes, italics refer to HDV ribozyme (3′ end) and underlined italics refer to T7 promoter (5′ end) and terminator (3′ end). The start sequences of transcription (GS=Gene Start) and the transcription termination sequences (GE=Gene End) are indicated in the map and the sequences are underlined. An encircled T (position 3190 in FIG. 4c) refers to a surrounded nucleotide (before PacI-FseI insertion): this is a T (position 3190 of SEQ ID NO:24) in the assembled AVINEW® genome into the transcription vector (T comes from the primer used for creating the PacI and FseI restriction sites). In the consensus AVINEW® genome (SEQ ID NO:1), the nucleotide at the corresponding position 3150 is a C.
FIG. 5 depicts the plasmid map of the plasmid pIV32.
FIG. 6 depicts the plasmid map of the plasmid pIV33.
FIG. 7 depicts the plasmid map of the plasmid pIV034.
FIG. 8 depicts the plasmid map of the plasmid pNS151.
FIG. 9 depicts the schematic method to introduce the AIV HA gene into the NDV genome via an NDV insertion cassette.
FIG. 10 depicts the plasmid map of the plasmid pIV039.
FIGS. 11A and 11B depict HA expression by the engineered NDV vAVW02. The vAVW01 that does not contain insert is used as a negative control. HA expression is detected by Western blot in the allantoic fluid of virus-inoculated embryonated eggs (left panel in FIG. 11A) or from an infected CHO cell lysate (right panel of FIG. 11A) or by immunofluorescence in infected CHO cells (FIG. 11B) using an anti-H5 positive chicken serum on infected CHO cells.
FIGS. 12A and 12B are a table showing the SEQ ID NO assigned to DNA and protein sequences.
FIG. 13 depicts anti-NDV and anti-AI (against either H5N1 Cl2 or H5N9LP antigens) Maternally Derived Antibody (MDA) HI titers in the one-day-old chicken progeny of different groups of vaccinated SPF layers.
FIG. 14 depicts a vaccination/challenge timeline and protocol for evaluation of avian influenza protection induced by engineered NDV in SPF chickens.
FIG. 15 shows the kinetics charts of mortality of chickens with no MDA (SPF) or NDV MDAs (21A), or NDV and H5 MDAs or H5 only MDAs (21B) vaccinated at day-of-age with either vAVW01 (v01 or 01; no inserted gene) or vAVW03 (v03 or 03; AI HA insert).
FIGS. 16A-16D depict a comparison of AIV shedding from oral (A & C) and cloacal (B & D) swabs in chickens without (SPF) or with MDAs vaccinated with vAVW01 or vAVW03. The results in C and D are expressed as the ratio in log 10 between mean levels of HPAI H5N1 challenge shedding of vAVW01-immunized chickens and those of vAVW03-immunized chickens at different time points after challenge.
FIG. 17 depicts an NDV MDA effect (SPF: no MDA; NDV: anti-NDV MDAs) on vAVW03-induced AIV HI titers (using H5N9 (A) or H5N1 clade 2.2 (B) antigens) after vaccination (D21) and after challenge (D35). Numbers written on the figure correspond to number of positive serums/total tested. In presence of NDV MDA, AIV HI titers were higher after vaccination and did not increase after challenge compared to results in SPF chicks without NDV MDA.
FIG. 18 depicts D21 NDV HI titers post-vaccination (at D0) with vAVW01 or vAVW03 in chickens with no MDA (SPF), AI H5N9 and NDV MDAs (H5N9+NDV), NDV MDAs (NDV) or AI H5N1 (H5N1) MDAs; NDV MDA did not have a negative effect on the level of NDV HI titers induced by vAVW01 or vAVW03.
FIG. 19 depicts NDV HI titers after two vaccinations with AVINEW(G1), vAVW02(G2) and vAVW03(G3) at D0 and D21.
FIG. 20 depicts AI H5N1 HI titers after two vaccinations with vAVW02(G2) or vAVW03(G3) at D0 and D21.
FIG. 21 depicts AI H5N1 SN titers after two vaccinations with vAVW02(G2) or vAVW03(G3) at D0 and D21.
FIGS. 22A and 22 B depict NDV HI titers and AIV SN titer, respectively, induced by 1 (at D0) or 2 (at D0 and D14) eye drop administrations of vAVW03.
FIGS. 23A-23D depict kinetic of virus load (A and B) and of percentage of positive samples (C and D) in oropharyngeal (A and C) and cloacal (B and D) swabs from unvaccinated (Group 1) or vaccinated (Group 2: 1 administration of vAVW03 at D0; Group 3: 2 administrations of vAVW03 at D0 and D14; Group 4: prime-boost with vFP89 at D0 and vAVW03 at D14) Muscovy ducklings challenged with a HPAI H5N1 isolate at Day 28.
FIGS. 24A-24D depict kinetic of virus load (A and B) and of percentage of positive samples (C and D) in oropharyngeal (A and C) and cloacal (B and D) swabs from unvaccinated (Group 1) or vaccinated (Group 2: 1 administration of vAVW03 at D0; Group 3: 2 administrations of vAVW03 at D0 and D14; Group 4: prime-boost with vFP89 at D0 and vAVW03 at D14) Muscovy ducklings challenged with a HPAI H5N1 isolate at Day 42.
FIGS. 25A, 25B and 25C provide the sequence alignment between the avian influenza HA proteins and sequence identity percentage at the amino acid level.
FIGS. 26A, 26B, 26C, 26D, 26E and 26F provide the sequence alignment between the avian influenza HA proteins and sequence identity percentage at the nucleic acid level.



DETAILED DESCRIPTION
It is noted that in this disclosure and particularly in the claims and/or paragraphs, terms such as “comprises”, “comprised”, “comprising” and the like can have the meaning attributed to it in U.S. patent law; e.g., they can mean “includes”, “included”, “including”, and the like; and that terms such as “consisting essentially of” and “consists essentially of” have the meaning ascribed to them in U.S. patent law, e.g., they allow for elements not explicitly recited, but exclude elements that are found in the prior art or that affect a basic or novel characteristic of the invention.
Unless otherwise explained, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The singular terms “a”, “an”, and “the” include plural referents unless context clearly indicates otherwise. Similarly, the word “or” is intended to include “and” unless the context clearly indicate otherwise.
In the present invention, AVINEW vaccine strain is used as the vector. AVINEW is a live NDV vaccine (Merial Limited) that is widely used worldwide. This vaccine strain is naturally avirulent and presents a double respiratory and enteric tropism. Furthermore, the AVINEW strain belongs to a NDV genogroup (Class II, Genotype I) that may infect ducks. In contrast to LaSota, whose tropism is essentially directed to the respiratory tract, it does not induce respiratory side reactions.
The present invention relates to an avian vaccine that may comprise an effective amount of an engineered NDV vector and a pharmaceutically or veterinarily acceptable carrier, excipient, or vehicle.
The present invention encompasses any engineered NDV vector expressing a protein, polypeptide, antigen, epitope or immunogen that elicits an immunogenic response in an animal, such as an avian. The protein, polypeptide, antigen, epitope or immunogen may be an influenza protein, polypeptide, antigen, epitope or immunogen, such as, but not limited to, a protein, polypeptide, peptide or fragment(s) thereof, that elicit, induce or stimulate a response in an animal, such as an avian.
By “animal” is intended mammals, birds, and the like. Animal or host includes mammals and human. The animal may be selected from the group consisting of equine (e.g., horse), canine (e.g., dogs, wolves, foxes, coyotes, jackals), feline (e.g., lions, tigers, domestic cats, wild cats, other big cats, and other felines including cheetahs and lynx), ovine (e.g., sheep), bovine (e.g., cattle), porcine (e.g., pig), avian (e.g., chicken, duck, goose, turkey, quail, pheasant, parrot, finches, hawk, crow, ostrich, emu and cassowary), primate (e.g., prosimian, tarsier, monkey, gibbon, ape), and fish. The term “animal” also includes an individual animal in all stages of development, including embryonic and fetal stages.
In one embodiment, the avian influenza immunological composition or vaccine comprises an engineered vector and a pharmaceutical or veterinary acceptable excipient, carrier or vehicle. The engineered vector may be an NDV expression vector which may comprise a polynucleotide encoding an influenza protein, polypeptide, antigen, epitope or immunogen. The influenza protein, polypeptide, antigen, epitope or immunogen, may be a hemagglutinin, matrix protein, neuraminidase, nonstructural protein, nucleoprotein, polymerase, or any fragment thereof.
In another embodiment, the influenza protein, polypeptide, antigen, epitope or immunogen may be derived from an avian infected with influenza or an avian influenza strain. The avian influenza protein, antigen, epitope or immunogen may be a hemagglutinin (HA) such as, but not limited to, HA precursor, H1, H2, H3, H4, H5, H6, H7, H8, H9, H10, H11, H12, H13, H14, H15, or H16 protein, matrix protein (such as, but not limited to, matrix protein M1 or M2), neuraminidase (such as, but not limited to, NA1, NA2, NA3, NA4, NA5, NA6, NA7, NA8, or NA9), nonstructural (NS) protein (such as, but not limited to, NS1 or NS2), nucleoprotein (NP) and polymerase (such as, but not limited to, PA polymerase, PB1 polymerase 1 or PB2 polymerase 2).
The avian influenza antigen may be a hemagglutinin, such as an H5 HA. In one embodiment, the H5 is isolated from the H5N1 A/turkey/Turkey/1/2005 (clade 2.2), A/chicken/Indonesia/7/2003 (clade 2.1), the A/duck/Laos/3295/2006 (clade 2.3), the A/chicken/West Java/PWT-WIJ/2006 (clade 2.1) strains.
In another embodiment, the avian influenza protein, polypeptide, antigen, epitope or immunogen may be derived from an avian infected with influenza or an avian influenza strain derived from a recent isolate of any subtype.
As used herein, the term “antigen” or “immunogen” means a substance that induces a specific immune response in a host animal. The antigen may comprise a whole organism, killed, attenuated or live; a subunit or portion of an organism; a recombinant vector containing an insert expressing an epitope, polypeptide, peptide, protein, or fragment thereof with immunogenic properties; a piece or fragment of nucleic acid capable of inducing an immune response upon presentation to a host animal; a protein, a polypeptide, a peptide, an epitope, a hapten, or any combination thereof. Alternately, the immunogen or antigen may comprise a toxin or antitoxin.
The term “immunogenic protein or peptide” as used herein also includes peptides and polypeptides that are immunologically active in the sense that once administered to the host, it is able to evoke an immune response of the humoral and/or cellular type directed against the protein. Preferably the protein fragment is such that it has substantially the same immunological activity as the total protein. Thus, a protein fragment according to the invention comprises or consists essentially of or consists of at least one epitope or antigenic determinant. The term epitope, also known as antigenic determinant, is the part of a macromolecule recognized by the immune system and able to induce an immune reaction of the humoral type (B cells) and/or cellular type (T cells).
The term “immunogenic protein or peptide” further contemplates deletions, additions and substitutions to the sequence, so long as the polypeptide functions to produce an immunological response as defined herein. In this regard, particularly preferred substitutions will generally be conservative in nature, i.e., those substitutions that take place within a family of amino acids. For example, amino acids are generally divided into four families: (1) acidic—aspartate and glutamate; (2) basic—lysine, arginine, histidine; (3) non-polar—alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan; and (4) uncharged polar-glycine, asparagine, glutamine, cystine, serine threonine, tyrosine. Phenylalanine, tryptophan, and tyrosine are sometimes classified as aromatic amino acids. It is reasonably predictable that an isolated replacement of leucine with isoleucine or valine, or vice versa; an aspartate with a glutamate or vice versa; a threonine with a serine or vice versa; or a similar conservative replacement of an amino acid with a structurally related amino acid, will not have a major effect on the biological activity. Proteins having substantially the same amino acid sequence as the reference molecule but possessing minor amino acid substitutions that do not substantially affect the immunogenicity of the protein are, therefore, within the definition of the reference polypeptide.
The term epitope is the part of a macromolecule recognized by the immune system and able to induce an immune reaction of the humoral type (B cells) and/or cellular type (T cells). The term is also used interchangeably with “antigenic determinant” or “antigenic determinant site”. Antibodies that recognize the same epitope can be identified in a simple immunoassay showing the ability of one antibody to block the binding of another antibody to a target antigen.
An “immunological response” to a composition or vaccine is the development in the host of a cellular and/or antibody-mediated immune response to a composition or vaccine of interest. Usually, an “immunological response” includes but is not limited to one or more of the following effects: the production of antibodies, B cells, helper T cells, and/or cytotoxic T cells, directed specifically to an antigen or antigens included in the composition or vaccine of interest. Preferably, the host will display either a therapeutic or protective immunological response such that resistance to new infection will be enhanced and/or the clinical severity of the disease reduced. Such protection will be demonstrated by either a reduction or lack of symptoms normally displayed by an infected host, a quicker recovery time and/or a lowered viral titer in the infected host.
The terms “immunogenic” protein or polypeptide as used herein also refers to an amino acid sequence which elicits an immunological response as described above. An “immunogenic” protein or polypeptide, as used herein, includes the full-length sequence of the protein, analogs thereof, or immunogenic fragments thereof. By “immunogenic fragment” is meant a fragment of a protein which includes one or more epitopes and thus elicits the immunological response described above. Such fragments can be identified using any number of epitope mapping techniques, well known in the art. See, e.g., Epitope Mapping Protocols in Methods in Molecular Biology, Vol. 66 (Glenn E. Morris, Ed., 1996). For example, linear epitopes may be determined by e.g., concurrently synthesizing large numbers of peptides on solid supports, the peptides corresponding to portions of the protein molecule, and reacting the peptides with antibodies while the peptides are still attached to the supports. Such techniques are known in the art and described in, e.g., U.S. Pat. No. 4,708,871; Geysen et al., 1984; Geysen et al., 1986, all incorporated herein by reference in their entireties. Similarly, conformational epitopes are readily identified by determining spatial conformation of amino acids such as by, e.g., x-ray crystallography and 2-dimensional nuclear magnetic resonance. See, e.g., Epitope Mapping Protocols, supra. Methods especially applicable to the proteins of T. parva are fully described in the PCT Application Serial No. PCT/US2004/022605 incorporated herein by reference in its entirety.
Synthetic antigens are also included within the definition, for example, polyepitopes, flanking epitopes, and other recombinant or synthetically derived antigens. See, e.g., Bergmann et al., 1993; Bergmann et al., 1996; Suhrbier, 1997; Gardner et al., 1998. Immunogenic fragments, for purposes of the present invention, will usually include at least about 3 amino acids, preferably at least about 5 amino acids, more preferably at least about 10-15 amino acids, and most preferably about 15-25 amino acids or more amino acids, of the molecule. There is no critical upper limit to the length of the fragment, which could comprise nearly the full-length of the protein sequence, or even a fusion protein comprising at least one epitope of the protein.
Accordingly, a minimum structure of a polynucleotide expressing an epitope is that it comprises or consists essentially of or consists of nucleotides to encode an epitope or antigenic determinant of an influenza protein or polyprotein. A polynucleotide encoding a fragment of the total protein or polyprotein, more advantageously, comprises or consists essentially of or consists of a minimum of 15 nucleotides, advantageously about 30-45 nucleotides, and preferably about 45-75, at least 57, 87 or 150 consecutive or contiguous nucleotides of the sequence encoding the total protein or polyprotein. Epitope determination procedures, such as, generating overlapping peptide libraries (Hemmer et al., 1998), Pepscan (Geysen et al., 1984; Geysen et al., 1985; Van der Zee R. et al., 1989; Geysen, 1990; Multipin® Peptide Synthesis Kits de Chiron) and algorithms (De Groot et al., 1999), and in PCT Application Serial No. PCT/US2004/022605 all of which are incorporated herein by reference in their entireties can be used in the practice of the invention, without undue experimentation. Other documents cited and incorporated herein may also be consulted for methods for determining epitopes of an immunogen or antigen and thus nucleic acid molecules that encode such epitopes.
A “polynucleotide” is a polymeric form of nucleotides of any length that contains deoxyribonucleotides, ribonucleotides, and analogs in any combination. Polynucleotides may have three-dimensional structure, and may perform any function, known or unknown. The term “polynucleotide” includes double-, single-stranded, and triple-stranded helical molecules. Unless otherwise specified or required, any embodiment of the invention described herein that is a polynucleotide encompasses both the double stranded form and each of two complementary forms known or predicted to make up the double stranded form of either the DNA, RNA or hybrid molecule.
The term “codon optimization” refers to the process of optimally configuring the nucleic acid sequence encoding a protein, polypeptide, antigen, epitope, domain or fragment for expression/translation in a selected host. In general, gene expression levels depend on many factors, such as promoter sequences and regulatory elements. One of the most important factors is the adaptation of the codon usage of the transcript gene to the typical codon usage of the host (Lithwich, G. and Margalit, H., Genome Res. 13, 2665-2673, 2003). Therefore, highly expressed genes in prokaryotic genomes under translational selection have a pronounced codon usage bias. This is because they use a small subset of codons that are recognized by the most abundant tRNA species (Ikemura, T., J. Mol. Biol. 151, 389-409, 1981). The force that modulates this codon adaptation is called translational selection and its strength is important in fast-growing bacteria (Rocha, E. P., Genome Res. 14, 2279-2286, 2004; Sharp, P. M. et al., Nucleic Acids Res. 33, 1141-1153). If a gene contains codons that are rarely used by the host, its expression level will not be maximal. This may be one of the limitations of heterologous protein expression (Gustafsson, C. et al., Trends Biotechnol. 22, 346-353, 2004) and the development of DNA vaccines (Ivory, C. and Chadee, K., Genet. Vaccines Ther. 2, 17, 2004). A high number of synthetic genes have been re-designed to increase their expression level. The Synthetic Gene Database (SGDB) (Wu G. et al., Nucleic Acids Res. 35, D76-D79, 2007) contains information from more than 200 published experiments on synthetic genes. In the design process of a nucleic acid sequence that will be inserted into a new host to express a certain protein in optimal amounts, codon usage optimization is usually one of the first steps (Gustafsson, C., Trends Biotechnol. 22, 346-353, 2004). Codon usage optimization basically involves altering the rare codons in the target gene so that they more closely reflect the codon usage of the host without modifying the amino acid sequence of the encoded protein (Gustafsson, C., Trends Biotechnol. 22, 346-353, 2004). The information usually used for the optimization process is therefore the DNA or protein sequence to be optimized and a codon usage table (reference set) of the host.
There are several public web servers and stand-alone applications that allow some kind of codon optimization by anyone skilled in the art. ‘GeneDesign’ (Richardson, S. M. et al., Genome Res. 16, 550-556, 2006), ‘Synthetic Gene Designer’ (Wu G. et al., Protein Expr. Purif. 47, 441-445, 2006) and ‘Gene Designer’ (Villalobos, A. et al., BMC Bioinformatics 7, 285, 2006) are packages that provide a platform for synthetic gene design, including a codon optimization step. With regard to the methods for codon usage optimization available in each server or program, the first programs developed used only the ‘one amino acid-one codon’ approach. More recent programs and servers now include further methods to create some codon usage variability. This variability reflects the codon usage variability of natural highly expressed genes and enables additional criteria to be introduced (such as the avoidance of restriction sites) in the optimization process. Most applications and web servers described herein provide three methods of codon optimization: a complete optimization of all codons, an optimization based on the relative codon usage frequencies of the reference set that uses a Monte Carlo approach and a novel approaches designed to maximize the optimization with the minimum changes between the query and optimized sequences. In one embodiment herein, the sequences encoding the protein complement of NDV are codon optimized for expression in avian cells, in a preferred embodiment the nucleic acid sequences that encode NDV P, L and NP are codon optimized for expression in avian cells. In yet another embodiment, the nucleic acid sequence encoding the recombinant protein, antigen, peptide, polypeptide, fragment, domain, or epitope is codon optimized for expression in avian. In another embodiment, the codon optimized sequences encode AIV proteins, antigens, peptides, polypeptides, fragments, domains, or epitopes for avian expression. In yet another embodiment, the codon optimized sequences encode AIV HA and/or N proteins, antigens, peptides, polypeptides, fragments, domains, or epitopes for avian expression.
The following are non-limiting examples of polynucleotides: a gene or gene fragment, exons, introns, mRNA, tRNA, rRNA, siRNA, ribozymes, cDNA, recombinant polynucleotides, branched polynucleotides, plasmids, vectors, isolated DNA of any sequence, isolated RNA of any sequence, nucleic acid probes and primers. A polynucleotide may comprise modified nucleotides, such as methylated nucleotides and nucleotide analogs, uracil, other sugars and linking groups such as fluororibose and thiolate, and nucleotide branches. The sequence of nucleotides may be further modified after polymerization, such as by conjugation, with a labeling component. Other types of modifications included in this definition are caps, substitution of one or more of the naturally occurring nucleotides with an analog, and introduction of means for attaching the polynucleotide to proteins, metal ions, labeling components, other polynucleotides or solid support. The polynucleotides can be obtained by chemical synthesis or derived from a microorganism.
The invention further comprises a complementary strand to a polynucleotide encoding an influenza protein, antigen, epitope or immunogen. The complementary strand can be polymeric and of any length, and can contain deoxyribonucleotides, ribonucleotides, and analogs in any combination thereof.
The terms “protein”, “peptide”, “polypeptide” and “polypeptide fragment” are used interchangeably herein to refer to polymers of amino acid residues of any length. The polymer can be linear or branched, it may comprise modified amino acids or amino acid analogs, and it may be interrupted by chemical moieties other than amino acids. The terms also encompass an amino acid polymer that has been modified naturally or by intervention; for example disulfide bond formation, glycosylation, lipidation, acetylation, phosphorylation, or any other manipulation or modification, such as conjugation with a labeling or bioactive component.
An “isolated” polynucleotide or polypeptide is one that is substantially free of the materials with which it is associated in its native environment. By substantially free, is meant at least 50%, at least 70%, at least 80%, at least 90%, or at least 95% free of these materials.
Hybridization reactions can be performed under conditions of different “stringency.” Conditions that increase stringency of a hybridization reaction are well known. See for example, “Molecular Cloning: A Laboratory Manual”, second edition (Sambrook et al., 1989). Examples of relevant conditions include (in order of increasing stringency): incubation temperatures of 25° C., 37° C., 50° C., and 68° C.; buffer concentrations of 10×SSC, 6×SSC, 1×SSC, 0.1×SSC (where SSC is 0.15 M NaCl and 15 mM citrate buffer) and their equivalent using other buffer systems; formamide concentrations of 0%, 25%, 50%, and 75%; incubation times from 5 minutes to 24 hours; 1, 2 or more washing steps; wash incubation times of 1, 2, or 15 minutes; and wash solutions of 6×SSC, 1×SSC, 0.1×SSC, or deionized water.
The invention further encompasses polynucleotides encoding functionally equivalent variants and derivatives of the influenza polypeptides and functionally equivalent fragments thereof that may enhance, decrease or not significantly affect inherent properties of the polypeptides encoded thereby. These functionally equivalent variants, derivatives, and fragments display the ability to retain influenza activity. For instance, changes in a DNA sequence that do not change the encoded amino acid sequence, as well as those that result in conservative substitutions of amino acid residues, one or a few amino acid deletions or additions, and substitution of amino acid residues by amino acid analogs are those which will not significantly affect properties of the encoded polypeptide. Conservative amino acid substitutions are glycine/alanine; valine/isoleucine/leucine; asparagine/glutamine; aspartic acid/glutamic acid; serine/threonine/methionine; lysine/arginine; and phenylalanine/tyrosine/tryptophan. In one embodiment, the variants have at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% homology or identity to the influenza polynucleotide or polypeptide of interest.
In one aspect, the present invention provides influenza polypeptides, particularly avian influenza polypeptides. In another aspect, the present invention provides a polypeptide having a sequence as set forth in SEQ ID NO: 15, 17, 19, 21, or 23, and variant or fragment thereof.
In another aspect, the present invention provides a polypeptide having at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, 96%, 97%, 98% or 99% sequence identity to an avian HA polypeptide of the invention, particularly to the polypeptides having a sequence as set forth in SEQ ID NO: 15, 17, 19, 21, or 23.
In yet another aspect, the present invention provides fragments and variants of the influenza polypeptides identified above (SEQ ID NO: 15, 17, 19, 21 and 23) which may readily be prepared by one of skill in the art using well-known molecular biology techniques.
Variants are homologous polypeptides having an amino acid sequence at least about 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity to the antigenic polypeptides of the invention, particularly to the amino acid sequence as set forth in SEQ ID NO: 15, 17, 19, 21, or 23.
An immunogenic fragment of an influenza polypeptide includes at least 8, 10, 15, or consecutive amino acids, at least 21 amino acids, at least 23 amino acids, at least 25 amino acids, or at least 30 amino acids of an influenza polypeptide having a sequence as set forth in SEQ ID NO: 2, 4, 5, 8, 10, 12, or 14, or variants thereof. In another embodiment, a fragment of an influenza polypeptide includes a specific antigenic epitope found on a full-length influenza polypeptide.
In another aspect, the present invention provides a polynucleotide encoding an influenza HA polypeptide, such as a polynucleotide encoding a polypeptide having a sequence as set forth in SEQ ID NO: 15, 17, 19, 21, or 23. In yet another aspect, the present invention provides a polynucleotide encoding a polypeptide having at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, 96%, 97%, 98% or 99% sequence identity to a polypeptide having a sequence as set forth in SEQ ID NO: 15, 17, 19, 21, or 23, or a conservative variant, an allelic variant, a homolog or an immunogenic fragment comprising at least eight or at east ten consecutive amino acids of one of these polypeptides, or a combination of these polypeptides. The polynucleotide encoding the influenza HA polypeptide may be codon-optimized for expression in a specific animal species. The HA protein may be modified at the cleavage site from a highly pathogenic avian influenza sequence (multiple basic amino acids: RERRRKKR—SEQ ID NO:25) to a low pathogenic avian influenza sequence (RETR—SEQ ID NO:26).
In another aspect, the present invention provides a polynucleotide having a nucleotide sequence as set forth in SEQ ID NO: 14, 16, 18, 21, 22, or a variant thereof. In yet another aspect, the present invention provides a polynucleotide having at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 95%, 96%, 97%, 98% or 99% sequence identity to one of a polynucleotide having a sequence as set forth in SEQ ID NO: 14, 16, 18, 21, 22, or a variant thereof.
For the purposes of the present invention, sequence identity or homology is determined by comparing the sequences when aligned so as to maximize overlap and identity while minimizing sequence gaps. In particular, sequence identity may be determined using any of a number of mathematical algorithms. A non-limiting example of a mathematical algorithm used for comparison of two sequences is the algorithm of Karlin et al., 1990 modified as in Karlin et al., 1993.
Another example of a mathematical algorithm used for comparison of sequences is the algorithm of Myers et al., 1988. Such an algorithm is incorporated into the ALIGN program (version 2.0) which is part of the GCG sequence alignment software package. When utilizing the ALIGN program for comparing amino acid sequences, a PAM120 weight residue table, a gap length penalty of 12, and a gap penalty of 4 can be used. Yet another useful algorithm for identifying regions of local sequence similarity and alignment is the FASTA algorithm as described in Pearson et al., 1988.
In general, comparison of amino acid sequences is accomplished by aligning an amino acid sequence of a polypeptide of a known structure with the amino acid sequence of a polypeptide of unknown structure. Amino acids in the sequences are then compared and groups of amino acids that are homologous are grouped together. This method detects conserved regions of the polypeptides and accounts for amino acid insertions and deletions. Homology between amino acid sequences can be determined by using commercially available algorithms (see also the description of homology above). In addition to those otherwise mentioned herein, mention is made too of the programs BLAST, gapped BLAST, BLASTN, BLASTP, and PSI-BLAST, provided by the National Center for Biotechnology Information. These programs are widely used in the art for this purpose and can align homologous regions of two amino acid sequences.
In all search programs in the suite, the gapped alignment routines are integral to the database search itself. Gapping can be turned off if desired. The default penalty (Q) for a gap of length one is Q=9 for proteins and BLASTP, and Q=10 for BLASTN, but may be changed to any integer. The default per-residue penalty for extending a gap (R) is R=2 for proteins and BLASTP, and R=10 for BLASTN, but may be changed to any integer. Any combination of values for Q and R can be used in order to align sequences so as to maximize overlap and identity while minimizing sequence gaps. The default amino acid comparison matrix is BLOSUM62, but other amino acid comparison matrices such as PAM can be utilized.
Alternatively or additionally, the term “homology” or “identity”, for instance, with respect to a nucleotide or amino acid sequence, can indicate a quantitative measure of homology between two sequences. The percent sequence identity can be calculated as (Nref−Ndif)*100/Nref, wherein Ndif is the total number of non-identical residues in the two sequences when aligned and wherein Nref is the number of residues in one of the sequences. Hence, the DNA sequence AGTCAGTC will have a sequence identity of 75% with the sequence AATCAATC (Nref=8; Ndif=2).
Alternatively or additionally, “homology” or “identity” with respect to sequences can refer to the number of positions with identical nucleotides or amino acids divided by the number of nucleotides or amino acids in the shorter of the two sequences wherein alignment of the two sequences can be determined in accordance with the Wilbur and Lipman algorithm (Wilbur et al., 1983, incorporated herein by reference), for instance, using a window size of 20 nucleotides, a word length of 4 nucleotides, and a gap penalty of 4, and computer-assisted analysis and interpretation of the sequence data including alignment can be conveniently performed using commercially available programs (e.g., Vector NTI SoftwareTM, Invitrogen Inc. CA, USA). When RNA sequences are said to be similar, or have a degree of sequence identity or homology with DNA sequences, thymidine (T) in the DNA sequence is considered equal to uracil (U) in the RNA sequence. Thus, RNA sequences are within the scope of the invention and can be derived from DNA sequences, by thymidine (T) in the DNA sequence being considered equal to uracil (U) in RNA sequences.
And, without undue experimentation, the skilled artisan can consult with many other programs or references for determining percent homology.
The invention further encompasses the influenza polynucleotides contained in a vector molecule or an expression vector and operably linked to a promoter element and optionally to an enhancer.
A “vector” refers to a recombinant DNA or RNA plasmid, bacteriophage, or virus that comprises a heterologous polynucleotide to be delivered to a target cell, either in vitro or in vivo. The heterologous polynucleotide may comprise a sequence of interest for purposes of prevention or therapy, and may optionally be in the form of an expression cassette. As used herein, a vector needs not be capable of replication in the ultimate target cell or subject. The term includes vectors for cloning as well as viral vectors.
The term “engineered” or “recombinant” means a polynucleotide of semisynthetic, or synthetic origin that either does not occur in nature or is linked to another polynucleotide in an arrangement not found in nature.
“Heterologous” means derived from a genetically distinct entity from the rest of the entity to which it is being compared. For example, a polynucleotide may be incorporated by genetic engineering techniques into a plasmid or vector derived from a different source, and is thus a heterologous polynucleotide. A promoter removed from its native coding sequence and operatively linked to a coding sequence other than the native sequence is a heterologous promoter.
The polynucleotides of the invention may comprise additional sequences, such as additional encoding sequences within the same transcription unit, controlling elements such as promoters, ribosome binding sites, 5′UTR, 3′UTR, transcription terminators, polyadenylation sites, additional transcription units under control of the same or a different promoter, sequences that permit cloning, expression, homologous recombination, and transformation of a host cell, and any such construct as may be desirable to provide embodiments of this invention.
Elements for the expression of an influenza polypeptide, antigen, epitope or immunogen are advantageously present in an inventive vector. In minimum manner, this comprises, consists essentially of, or consists of an initiation codon (ATG), a stop codon and a promoter, and optionally also a polyadenylation sequence for certain vectors such as plasmid and certain viral vectors, e.g., viral vectors other than poxviruses. When the polynucleotide encodes a polyprotein fragment, e.g. an influenza peptide, advantageously, in the vector, an ATG is placed at 5′ of the reading frame and a stop codon is placed at 3′. Other elements for controlling expression may be present, such as enhancer sequences, stabilizing sequences, such as intron and or untranslated 5′ or 3′ sequences and signal sequences permitting the secretion of the protein.
Methods for making and/or administering a vector or recombinants or plasmid for expression of gene products of genes of the invention either in vivo or in vitro can be any desired method, e.g., a method which is by or analogous to the methods disclosed in, or disclosed in documents cited in: U.S. Pat. Nos. 4,603,112; 4,769,330; 4,394,448; 4,722,848; 4,745,051; 4,769,331; 4,945,050; 5,494,807; 5,514,375; 5,744,140; 5,744,141; 5,756,103; 5,762,938; 5,766,599; 5,990,091; 5,174,993; 5,505,941; 5,338,683; 5,494,807; 5,591,639; 5,589,466; 5,677,178; 5,591,439; 5,552,143; 5,580,859; 6,130,066; 6,004,777; 6,130,066; 6,497,883; 6,464,984; 6,451,770; 6,391,314; 6,387,376; 6,376,473; 6,368,603; 6,348,196; 6,306,400; 6,228,846; 6,221,362; 6,217,883; 6,207,166; 6,207,165; 6,159,477; 6,153,199; 6,090,393; 6,074,649; 6,045,803; 6,033,670; 6,485,729; 6,103,526; 6,224,882; 6,312,682; 6,348,450; 6,312,683, and 6,596,279; U.S. patent application Ser. No. 920,197, filed Oct. 16, 1986; WO 90/01543; WO91/11525; WO 94/16716; WO 96/39491; WO 98/33510; EP 265785; EP 0 370 573; Andreansky et al., 1996; Ballay et al., 1993; Felgner et al., 1994; Frolov et al., 1996; Graham, 1990; Grunhaus et al., 1992; Ju et al., 1998; Kitson et al., 1991; McClements et al., 1996; Moss, 1996; Paoletti, 1996; Pennock et al., 1984; Richardson (Ed), 1995; Smith et al., 1983; Robertson et al., 1996; Robinson et al., 1997; and Roizman, 1996. The herein cited and incorporated herein by reference documents, in addition to providing examples of vectors useful in the practice of the invention, can also provide sources for non-influenza peptides or fragments thereof to be expressed by vector or vectors in, or included in, the compositions of the invention.
The present invention also relates to preparations comprising vectors, such as expression vectors, e.g., prophylactic or therapeutic compositions. The preparations can comprise, consist essentially of, or consist of one or more vectors, e.g., expression vectors, such as in vivo expression vectors, comprising, consisting essentially or consisting of (and advantageously expressing) one or more of influenza polypeptides, antigens, epitopes or immunogens. The vector contains and expresses a polynucleotide that comprises, consists essentially of, or consists of a polynucleotide coding for (and advantageously expressing) an influenza antigen, epitope or immunogen, in a pharmaceutically or veterinarily acceptable carrier, excipient or vehicle. Thus, according to an embodiment of the invention, the other vector or vectors in the preparation comprises, consists essentially of or consists of a polynucleotide that encodes, and under appropriate circumstances the vector expresses one or more other proteins of an influenza polypeptide, antigen, epitope or immunogen (e.g., hemagglutinin, neuraminidase, nucleoprotein) or a fragment thereof.
According to another embodiment, the vector or vectors in the preparation comprise, or consist essentially of, or consist of polynucleotide(s) encoding one or more proteins or fragment(s) thereof of an influenza polypeptide, antigen, epitope or immunogen, the vector or vectors expressing the polynucleotide(s). The inventive preparation comprises, consists essentially of, or consists of, at least two vectors comprising, consisting essentially of, or consisting of, and advantageously also expressing, in vivo under appropriate conditions or suitable conditions or in a suitable host cell, polynucleotides from different influenza isolates encoding the same proteins and/or for different proteins. Preparations containing one or more vectors comprising, consisting essentially of or consisting of polynucleotides encoding, and advantageously expressing, in vivo, an influenza polypeptide, antigen, fusion protein or an epitope thereof. The invention is also directed at mixtures of vectors that contain, consist essentially of, or consist of coding for, and express, different influenza proteins, polypeptides, antigens, epitopes or immunogens, e.g., an influenza polypeptide, antigen, epitope or immunogen from different species such as, but not limited to, humans, horses, pigs, seals, whales, in addition to avian species including chicken, turkeys, ducks and geese.
The term plasmid covers any DNA transcription unit comprising a polynucleotide according to the invention and the elements necessary for its in vivo expression in a cell or cells of the desired host or target; and, in this regard, it is noted that a supercoiled plasmid and all of its topoisomers, open-circular plasmid, as well as linear forms of the plasmid, are intended to be within the scope of the invention.
Each plasmid comprises or contains or consists essentially of, in addition to the heterologous polynucleotide encoding a recombinant protein, antigen, epitope or immunogen, optionally fused with a polynucleotide encoding an heterologous peptide sequence, variant, analog or fragment, operably linked to a promoter or under the control of a promoter or dependent upon a promoter. In general, it is advantageous to employ a strong promoter that is functional in eukaryotic cells. The preferred strong promoter is the immediate early cytomegalovirus promoter (CMV-IE) of human or murine origin, or optionally having another origin such as the rat or guinea pig. The CMV-IE promoter can comprise the actual promoter segment, which may or may not be associated with the enhancer segment. Reference can be made to EP-A-260 148, EP-A-323 597, U.S. Pat. Nos. 5,168,062, 5,385,839, and 4,968,615, as well as to PCT Application No WO87/03905. The CMV-IE promoter is advantageously a human CMV-IE (Boshart et al., 1985) or murine CMV-IE. In more general terms, the promoter is either of a viral or a cellular origin. A strong viral promoter other than CMV-IE that may be usefully employed in the practice of the invention is the early/late promoter of the SV40 virus or the LTR promoter of the Rous sarcoma virus. A strong cellular promoter that may be usefully employed in the practice of the invention is the promoter of a gene of the cytoskeleton, such as e.g. the desmin promoter (Kwissa et al., 2000), or the actin promoter (Miyazaki et al., 1989).
Functional sub fragments of these promoters, i.e., portions of these promoters that maintain an adequate promoting activity, are included within the present invention, e.g. truncated CMV-IE promoters according to PCT Application No. WO98/00166 or U.S. Pat. No. 6,156,567 can be used in the practice of the invention. A promoter in the practice of the invention consequently includes derivatives and sub fragments of a full-length promoter that maintain an adequate promoting activity and hence function as a promoter, preferably promoting activity substantially similar to that of the actual or full-length promoter from which the derivative or sub fragment is derived, e.g., akin to the activity of the truncated CMV-IE promoters of U.S. Pat. No. 6,156,567 to the activity of full-length CMV-IE promoters. Thus, a CMV-IE promoter in the practice of the invention can comprise or consist essentially of or consist of the promoter portion of the full-length promoter and/or the enhancer portion of the full-length promoter, as well as derivatives and sub fragments.
Preferably, the plasmids comprise or consist essentially of other expression control elements. It is particularly advantageous to incorporate stabilizing sequence(s), e.g., intron sequence(s), preferably the first intron of the hCMV-IE (PCT Application No. WO89/01036), the intron II of the rabbit β-globin gene (van Ooyen et al., 1979).
As to the polyadenylation signal (polyA) for the plasmids and viral vectors other than poxviruses, use can more be made of the poly(A) signal of the bovine growth hormone (bGH) gene (see U.S. Pat. No. 5,122,458), or the poly(A) signal of the rabbit β-globin gene or the poly(A) signal of the SV40 virus.
According to another embodiment of the invention, the expression vectors are expression vectors used for the in vitro expression of proteins in an appropriate cell system. The expressed proteins can be harvested in or from the culture supernatant after, or not after secretion (if there is no secretion a cell lysis typically occurs or is performed), optionally concentrated by concentration methods such as ultrafiltration and/or purified by purification means, such as affinity, ion exchange or gel filtration-type chromatography methods.
A “host cell” denotes a prokaryotic or eukaryotic cell that has been genetically altered, or is capable of being genetically altered by administration of an exogenous polynucleotide, such as a recombinant plasmid or vector. When referring to genetically altered cells, the term refers both to the originally altered cell and to the progeny thereof. Advantageous host cells include, but are not limited to, baby hamster kidney (BHK) cells, colon carcinoma (Caco-2) cells, COS7 cells, MCF-7 cells, MCF-10A cells, Madin-Darby canine kidney (MDCK) lines, mink lung (MvlLu) cells, MRC-5 cells, U937 cells and VERO cells. Polynucleotides comprising a desired sequence can be inserted into a suitable cloning or expression vector, and the vector in turn can be introduced into a suitable host cell for replication and amplification. Polynucleotides can be introduced into host cells by any means known in the art. The vectors containing the polynucleotides of interest can be introduced into the host cell by any of a number of appropriate means, including direct uptake, endocytosis, transfection, f-mating, electroporation, transfection employing calcium chloride, rubidium chloride, calcium phosphate, DEAE-dextran, or other substances; microprojectile bombardment; lipofection; and infection (where the vector is infectious, for instance, a retroviral vector). The choice of introducing vectors or polynucleotides will often depend on features of the host cell.
In one embodiment of the present invention, the vector is a Newcastle Disease Virus (NDV) vector. Newcastle disease virus also designated as avian paramyxovirus 1 (APMV1, family Paramyxoviridae, subfamily Paramyxovirinae, genus Avulavirus) is an avian pathogen whose naturally occurring strains exhibit a wide range of disease severity. NDV is particularly advantageous as a vaccine vector for veterinary use because the vector itself serves as a needed poultry vaccine. NDV strain pathotypes are asymptomatic enteric (e.g., Ulster 2C, Queensland V4), lentogenic (e.g., Hitchner B1, F (e.g., Asplin), La Sota), mesogenic (e.g., strain H, Mukteswar, Roakin, Beaudette C) or velogenic (e.g., Texas GB, NY parrot 70181, Italien, Milano, Herts 33/56). Advantages of avian influenza vector vaccines based on the NDV vector include, but are not limited to, (1) induce a broad immunity, including humoral, cellular and mucosal responses (2) do not express NP and M proteins and therefore is compatible with the DIVA (differentiate infected from vaccinated animals) strategy, (3) induce rapid onset of immunity, (4) bivalent and (5) production poses less risk for the environment than inactivated vaccines in case of accidental release.
Certain characteristics of NDV suggest that recombinant NDV (rNDV) or engineered NDV expressing a foreign viral protein would be very good vaccine candidates. NDV grows to very high titers in many cell lines and eggs, and it elicits strong humoral and cellular immune responses in vivo. NDV naturally infects via respiratory and alimentary tract mucosal surfaces, so it is especially useful to deliver protective antigens of respiratory disease pathogens such as AIV. In addition, commercially available live NDV vaccines are widely used in the United States and most other countries. Vaccines based on live NDV recombinants may also have advantages over other live recombinant vaccine vectors. First, the foreign protein is expressed with only a few NDV proteins. In contrast, pox and herpes virus vectors express a large number of additional proteins from their large-size genomes. For the generation of specific immune responses in vaccine applications, it may be advantageous to have only a limited number of proteins expressed. Second, NDV replicates in the cytoplasm of the infected cells without a DNA phase, which eliminates the problem of integration of viral genome into the host cell DNA. The virus does not undergo detectable genetic recombination
Another application of reverse genetics is to develop a more effective and better NDV vaccine as described herein. Current NDV vaccines utilize naturally occurring lentogenic strains, such as the Hitchner B1 and LaSota. As encountered with other live attenuated vaccines, the current NDV vaccines may still cause disease due to reversion to virulence. The choice of the NDV vaccine strain as the vector is important since first data reported with the Hitchner B1 NDV strain were disappointing. Later, data obtained with the LaSota NDV strain was encouraging and vaccine candidates based on this strain are being used in the field in China and Mexico.
The invention herein, describes the applicant's use of the NDV AVINEW® vaccine strain as the vector for delivery of recombinant-derived antigens to avians. More specifically the antigens may be avian influenza virus (AIV) antigens. AVINEW® is a live NDV vaccine developed by Merial Ltd. that is used worldwide. This vaccine strain is naturally avirulent and presents a double respiratory and enteric tropism. The divergent tropism in avians may afford unique biological characteristics to recombinant NDV (rNDV) or engineered NDV vaccines that utilize the AVINEW® backbone for gene delivery in avians with respect to interference from Maternally-Derived Antibodies (MDA) to NDV itself. Such resistance to MDA may allow active immunization of commercial and wild-type avians that may inherently have significant levels of NDV-specific MDAs and otherwise be recalcitrant to more conventional recombinant NDV immunization.
Furthermore, the AVINEW® strain belongs to a NDV genogroup or type (Class 2, genotype I) that may infect ducks. In contrast to LaSota, whose tropism is essentially directed to the respiratory tract, the AVINEW® strain does not induce respiratory side reactions.
In one embodiment, the NDV vector is NDV AVINEW®. The NDV vector may also be the vector of U.S. Pat. No. 5,118,502, in particular the strain deposited as ATCC No. VR 2239.
One embodiment of the invention provides the genomic DNA sequence and encoded protein sequences of AVINEW. The genomic DNA sequence of AVINEW NDV strain has a polynucleotide sequence as set forth in SEQ ID NO:1. The AVINEW genomic cDNA sequence (SEQ ID NO:1) is different from the VG/GA sequence (GenBank Accession No. EU289028). The sequence identity between AVINEW (SEQ ID NO:1) and VG/GA (EU289028) genomic sequences is 89.6%. The amino acid sequence identity between the proteins of the Avinew strain and the VG/GA strain is: 95.9% for NP protein (SEQ ID NO:3 of Avinew and GenBank No. ABZ80386), 89.7% for P protein (SEQ ID NO:5 of Avinew v. GenBank ABZ80387), 94.2% for M protein (SEQ ID NO:7 of Avinew v. GenBank No. ABZ80388), 92.4% for F protein (SEQ ID NO:9 of Avinew v. GenBank No. ABZ80389), 88.1% for HN protein (SEQ ID NO:11 of Avinew v. GenBank No. ABZ80390), and 96.9% for L protein (SEQ ID NO:13 of Avinew v. GenBank No. ABZ80391). The nucleic acid sequence identity between the genes of the Avinew train and the VG/GA strain is: 90.6% for NP gene (SEQ ID NO:2 of Avinew v. 122-1591 bp of EU289028), 88.6% for P gene (SEQ ID NO:4 of Avinew v. 1887-3074 bp of EU289028), 90.1% for M gene (SEQ ID NO:6 of Avinew v. 3290-4384 bp of EU289028), 90.0% for F gene (SEQ ID NO:8 of Avinew v. 4544-6205 bp of EU289028), 84.7% for FIN gene (SEQ ID NO:10 of Avinew v. 6412-8145 bp of EU289028), and 90.9% for L gene (SEQ ID NO:12 of Avinew v. 8381-14995 bp of EU289028). Comparison of the complete genomic and individual gene sequences with other available NDV reference sequences showed that the AVINEW NDV strain is genetically closely related to the Australian lentogenic strains 98-1154 and the Queensland V4. The sequence of the NDV 98-1154 complete genome is depicted in GenBank AY935491. The sequence identity between ANIVEW (SEQ ID NO:1) and AY935491 genomic sequences is 98.8%. The amino acid sequence identity between the proteins of the Avinew strain and the VG/GA strain is: 99.8% for NP protein (SEQ ID NO:3 of Avinew v. GenBank No. AAX45376), 97.7% for P protein (SEQ ID NO:5 of Avinew v. GenBank No. AAX45377), 98.4% for M protein (SEQ ID NO:7 of Avinew v. GenBank No. AAX45378), 98.7% for F protein (SEQ ID NO: 9 of Avinew v. GenBank No. AAX45379), 92.4% for FIN protein (SEQ ID NO:11 of Avinew v. GenBank No. AAX45380), and 99.5% for L protein (SEQ ID NO:13 of Avinew v. GenBank No. AAX45381). The nucleic acid sequence identity between the genes of the Avinew train and the VG/GA strain is: 99.0% for NP gene (SEQ ID NO:2 of Avinew v. 122-1591 bp of AY935491), 98.2% for P gene (SEQ ID NO:4 of Avinew v. 1887-3074 bp of AY935491), 98.6% for M gene (SEQ ID NO:6 of Avinew v. 3290-4384 bp of AY935491), 98.8% for F gene (SEQ ID NO:8 of Avinew v. 4544-6205 bp of AY935491), 93.1% for HN gene (SEQ ID NO:10 of Avinew v. 6412-8154 bp of AY935491), and 98.8% for L gene (SEQ ID NO:12 of Avinew v. 8381-14995 bp of AY935491). Only partial sequences are available in GenBank for Queensland V4.
In another embodiment, the invention provides a polynucleotide having a sequence as set forth in SEQ ID NO:1, 2, 4, 6, 8, 10, 12, or 24, and variant or fragment thereof. The invention further comprises a complementary strand to a polynucleotide described herein. In yet another embodiment, the invention provides a polypeptide having a sequence as set forth in SEQ ID NO:3, 5, 7, 9, 11, or 13, and variant or fragment thereof.
In another aspect, the present invention provides a genomic cDNA of AVINEW having the sequence as set forth in SEQ ID NO:1 or SEQ ID NO:24. In yet another embodiment, the polynucleotide is a reverse complementary strand of the polynucleotide having the sequence as set forth in SEQ ID NO:1 or SEQ ID NO:24. In yet another embodiment, the polynucleotide or a reverse complementary strand of a polynucleotide of the present invention has at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, 96%, 97%, 98% or 99% sequence identity to a polypeptide having a sequence as set forth in SEQ ID NO:1 or SEQ ID NO:24.
In one embodiment, the present invention provides a fragment of polynucleotide encoding an AVINEW polypeptide, such as a polynucleotide encoding a polypeptide having a sequence as set forth in SEQ ID NO: 3, 5, 7, 9, 11, or 13. In yet another aspect, the present invention provides a polynucleotide encoding a polypeptide having at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, 96%, 97%, 98% or 99% sequence identity to a polypeptide having a sequence as set forth in SEQ ID NO: 3, 5, 7, 9, 11, or 13, or a conservative variant, an allelic variant, a homolog or an immunogenic fragment comprising at least eight or at east ten consecutive amino acids of one of these polypeptides, or a combination of these polypeptides.
In another aspect, the present invention provides a polynucleotide having a nucleotide sequence as set forth in SEQ ID NO:1, 2, 4, 6, 8, 10, 12, or 24, or a variant thereof. In yet another embodiment, the polynucleotide is a reverse complementary strand of the polynucleotide having the sequence as set forth in SEQ ID NO:1, 2, 4, 6, 8, 10, 12, or 24. In yet another aspect, the present invention provides a polynucleotide or a reverse complementary strand of a polynucleotide having at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, 96%, 97%, 98% or 99% sequence identity to one of a polynucleotide having a sequence as set forth in SEQ ID NO:1, 2, 4, 6, 8, 10, 12, or 24, or a variant thereof.
In one aspect, the present invention relates to a pharmaceutical composition or vaccine for inducing an immunological response in a host animal inoculated with the vaccine or composition, the composition including a pharmaceutical acceptable carrier and a modified AVINEW recombinant virus. In yet another aspect of the invention, the engineered AVINEW virus includes, within a non-essential region of the virus genome, a heterologous DNA sequence which encodes an antigenic protein derived from a pathogen wherein the vaccine when administered to a host, is capable of inducing an immunological response specific to the protein encoded by the pathogen.
The term “nonessential region” refers to a region of a virus genome which is not essential for replication and propagation of the virus in tissue culture and whose deletion or inactivation may reduce virulence in a variety of animal systems. Any nonessential region or portion thereof can be deleted from the AVINEW genome or a foreign sequence can be inserted in it, and the viability and stability of the engineered AVINEW resulting from the deletion or insertion can be used to ascertain whether a deleted region or portion thereof is indeed nonessential. In another embodiment, the nonessential region of the AVINEW genome is the region between P gene and M gene, or the region between M gene and F gene of AVINEW genome. In yet another embodiment, the nonessential region may be in the region of 3075 nt-3289 nt or 4385 nt-4543 nt of SEQ ID NO:1, 3115 nt-3353 nt or 4449 nt-4607 nt of SEQ ID NO:24.
One aspect of the invention relates to NDV vectors expressing avian antigens. The antigen may be avian influenza antigen. The avian influenza antigen may be a hemagglutinin, such as H5 HA.
NDV vectors expressing avian influenza genes, such as a construct of NDV expressing a H5 subtype avian influenza virus (AIV) hemagglutinin (HA) with both a wild-type and mutated HA open reading frame (ORF) from the HPAIV wild bird isolate, A/Bar-headed goose/Qinghai/3/2005 (H5N1) inserted into the intergenic region between the P and M genes of the LaSota NDV vaccine strain (e.g., Ge et al., Journal of Virology, January 2007, vol. 81, no. 1, pp. 105-158), a complete cDNA clone of the Newcastle disease virus (NDV) vaccine strain Hitchner B1 expressing an influenza virus submitted to GenBank under accession number AF375823 (see, e.g., Nakaya et al., Journal of Virology, December 2001, pp. 11868-11873), a NDV recombinant (NDVH5Vm) which expresses the H5 protein of HPAIV A/chicken/Vietnam/P41/05 (H5N1) (see, e.g., Römer-Oberdorfer et al., Vaccine. 2008 May 2; 26(19):2307-13. Epub 2008 Mar. 18), rNDV-AIV-H7 constructed using a lentogenic paramyxovirus type 1 vector (NDV B1 strain) with insertion of the hemagglutinin (HA) gene from avian influenza virus (AIV) A/chicken/NY/13142-5/94 (H5N2) (see, e.g., Swayne et al., Avian Diseases 47:1047-1050, 2003), a NDV-expressing avian influenza virus (AIV) hemagglutinin (HA) of subtype H5 constructed by reverse genetics (see, e.g., Veits et al., PNAS, May 23, 2006, vol. 103, no. 21, pp. 8197-8202) and a recombinant NDV-H5 expressing the HA gene of AIV A/chicken/Vietnam/P41/2005 (H5N1) based on lentogenic NDV vaccine strain Clone 30 (see, e.g., Veits et al., Vaccine (2008) 26, 1688-1696) are also contemplated for the present invention.
In yet another embodiment of the present invention, an avian influenza virus expressing NDV genes, such as a chimeric avian influenza virus that expresses the ectodomain of the hemagglutinin-neuraminidase gene of NDV instead of the neuraminidase protein of the H5N1 avian influenza virus or a bivalent vaccine expressing the ectodomain of an H7 avian influenza virus hemagglutinin into a fusogenic and attenuated NDV gene (containing only its ectodomain, with the transmembrane and cytoplasmic domains derived from the F protein of NDV) (see, e.g., Park et al., PNAS, May 23, 2006, vol. 103, no. 21, pp. 8203-8308) are also contemplated.
In one embodiment, the invention provides for the administration of a therapeutically effective amount of a formulation for the delivery and expression of a protein, antigen, epitope or immunogen in a target cell. Determination of the prophylactically or therapeutically effective amount is routine experimentation for one of ordinary skill in the art. In another embodiment, the formulation comprises an expression vector comprising a polynucleotide that expresses an influenza antigen, epitope or immunogen and a pharmaceutically or veterinarily acceptable carrier, vehicle or excipient. In another embodiment, the pharmaceutically or veterinarily acceptable carrier, vehicle or excipient facilitates transfection and/or improves preservation of the vector or protein.
The pharmaceutically or veterinarily acceptable carriers or vehicles or excipients are well known to the one skilled in the art. For example, a pharmaceutically or veterinarily acceptable carrier or vehicle or excipient can be sterile water, a 0.9% NaCl (e.g., saline) solution or a phosphate buffer. Other pharmaceutically or veterinarily acceptable carrier or vehicle or excipients that can be used for methods of this invention include, but are not limited to, poly-(L-glutamate) or polyvinylpyrrolidone. The pharmaceutically or veterinarily acceptable carrier or vehicle or excipients may be any compound or combination of compounds facilitating the administration of the vector (or protein expressed from an inventive vector in vitro); advantageously, the carrier, vehicle or excipient may facilitate transfection and/or improve preservation of the vector (or protein). Doses and dose volumes are herein discussed in the general description and can also be determined by the skilled artisan from this disclosure read in conjunction with the knowledge in the art, without any undue experimentation.
The cationic lipids containing a quaternary ammonium salt which are advantageously but not exclusively suitable for plasmids, are advantageously those having the following formula:




in which R1 is a saturated or unsaturated straight-chain aliphatic radical having 12 to 18 carbon atoms, R2 is another aliphatic radical containing 2 or 3 carbon atoms and X is an amine or hydroxyl group, e.g. the DMRIE. In another embodiment the cationic lipid can be associated with a neutral lipid, e.g. the DOPE.
Among these cationic lipids, preference is given to DMRIE (N-(2-hydroxyethyl)-N,N-dimethyl-2,3-bis(tetradecyloxy)-1-propane ammonium; WO96/34109), advantageously associated with a neutral lipid, advantageously DOPE (dioleoyl-phosphatidyl-ethanol amine; Behr, 1994), to form DMRIE-DOPE.
Advantageously, the plasmid mixture with the adjuvant is formed extemporaneously and advantageously contemporaneously with administration of the preparation or shortly before administration of the preparation; for instance, shortly before or prior to administration, the plasmid-adjuvant mixture is formed, advantageously so as to give enough time prior to administration for the mixture to form a complex, e.g. between about 10 and about 60 minutes prior to administration, such as approximately 30 minutes prior to administration.
When DOPE is present, the DMRIE:DOPE molar ratio is advantageously about 95:about 5 to about 5:about 95, more advantageously about 1:about 1, e.g., 1:1.
The DMRIE or DMRIE-DOPE adjuvant: plasmid weight ratio can be between about 50:about 1 and about 1:about 10, such as about 10:about 1 and about 1:about 5, and advantageously about 1:about 1 and about 1:about 2, e.g., 1:1 and 1:2.
In another embodiment, pharmaceutically or veterinarily acceptable carrier, excipient, or vehicle may be a water-in-oil emulsion. Examples of suitable water-in-oil emulsions include oil-based water-in-oil vaccinal emulsions which are stable and fluid at 4° C. containing: from 6 to 50 v/v % of an antigen-containing aqueous phase, preferably from 12 to 25 v/v %, from 50 to 94 v/v % of an oil phase containing in total or in part a non-metabolizable oil (e.g., mineral oil such as paraffin oil) and/or metabolizable oil (e.g., vegetable oil, or fatty acid, polyol or alcohol esters), from 0.2 to 20 p/v % of surfactants, preferably from 3 to 8 p/v %, the latter being in total or in part, or in a mixture either polyglycerol esters, said polyglycerol esters being preferably polyglycerol (poly)ricinoleates, or polyoxyethylene ricin oils or else hydrogenated polyoxyethylene ricin oils. Examples of surfactants that may be used in a water-in-oil emulsion include ethoxylated sorbitan esters (e.g., polyoxyethylene (20) sorbitan monooleate (Tween 80®), available from AppliChem, Inc., Cheshire, Conn.) and sorbitan esters (e.g., sorbitan monooleate (Span 80®), available from Sigma Aldrich, St. Louis, Mo.). In addition, with respect to a water-in-oil emulsion, see also U.S. Pat. No. 6,919,084, e.g., Example 8 thereof, incorporated herein by reference. In some embodiments, the antigen-containing aqueous phase comprises a saline solution comprising one or more buffering agents. An example of a suitable buffering solution is phosphate buffered saline. In an advantageous embodiment, the water-in-oil emulsion may be a water/oil/water (W/O/W) triple emulsion (see, e.g., U.S. Pat. No. 6,358,500, incorporated herein by reference). Examples of other suitable emulsions are described in U.S. Pat. No. 7,371,395, incorporated herein by reference.
The immunological compositions and vaccines according to the invention may comprise or consist essentially of one or more adjuvants. Suitable adjuvants for use in the practice of the present invention are (1) polymers of acrylic or methacrylic acid, maleic anhydride and alkenyl derivative polymers, (2) immunostimulating sequences (ISS), such as oligodeoxyribonucleotide sequences having one or more non-methylated CpG units (Klinman et al., 1996; WO98/16247), (3) an oil in water emulsion, such as the SPT emulsion described on p 147 of “Vaccine Design, The Subunit and Adjuvant Approach” published by M. Powell, M. Newman, Plenum Press 1995, and the emulsion MF59 described on p 183 of the same work, (4) cation lipids containing a quaternary ammonium salt, e.g., DDA (5) cytokines, (6) aluminum hydroxide or aluminum phosphate, (7) saponin or (8) other adjuvants discussed in any document cited and incorporated by reference into the instant application, or (9) any combinations or mixtures thereof.
The oil in water emulsion (3), which is especially appropriate for viral vectors, can be based on: light liquid paraffin oil (European pharmacopoeia type), isoprenoid oil such as squalane, squalene, oil resulting from the oligomerization of alkenes, e.g. isobutene or decene, esters of acids or alcohols having a straight-chain alkyl group, such as vegetable oils, ethyl oleate, propylene glycol, di(caprylate/caprate), glycerol tri(caprylate/caprate) and propylene glycol dioleate, or esters of branched, fatty alcohols or acids, especially isostearic acid esters.
The oil is used in combination with emulsifiers to form an emulsion. The emulsifiers may be nonionic surfactants, such as: esters of on the one hand sorbitan, mannide (e.g. anhydromannitol oleate), glycerol, polyglycerol or propylene glycol and on the other hand oleic, isostearic, ricinoleic or hydroxystearic acids, said esters being optionally ethoxylated, or polyoxypropylene-polyoxyethylene copolymer blocks, such as Pluronic, e.g., L121.
Among the type (1) adjuvant polymers, preference is given to polymers of cross linked acrylic or methacrylic acid, especially cross linked by polyalkenyl ethers of sugars or polyalcohols. These compounds are known under the name carbomer (Pharmeuropa, vol. 8, no. 2, June 1996). One skilled in the art can also refer to U.S. Pat. No. 2,909,462, which provides such acrylic polymers cross linked by a polyhydroxyl compound having at least three hydroxyl groups, preferably no more than eight such groups, the hydrogen atoms of at least three hydroxyl groups being replaced by unsaturated, aliphatic radicals having at least two carbon atoms. The preferred radicals are those containing 2 to 4 carbon atoms, e.g. vinyls, allyls and other ethylenically unsaturated groups. The unsaturated radicals can also contain other substituents, such as methyl. Products sold under the name Carbopol (BF Goodrich, Ohio, USA) are especially suitable. They are cross linked by allyl saccharose or by allyl pentaerythritol. Among them, reference is made to Carbopol 974P, 934P and 971P.
As to the maleic anhydride-alkenyl derivative copolymers, preference is given to EMA (Monsanto), which are straight-chain or cross linked ethylene-maleic anhydride copolymers and they are, for example, cross linked by divinyl ether. Reference is also made to J. Fields et al., 1960.
With regard to structure, the acrylic or methacrylic acid polymers and EMA are preferably formed by basic units having the following formula:




in which:

    
    
        R1 and R2, which can be the same or different, represent H or CH3
        x=0 or 1, preferably x=1
        y=1 or 2, with x+y=2.
    
    


For EMA, x=0 and y=2 and for carbomers x=y=1.
These polymers are soluble in water or physiological salt solution (20 g/l NaCl) and the pH can be adjusted to 7.3 to 7.4, e.g., by soda (NaOH), to provide the adjuvant solution in which the expression vector(s) can be incorporated. The polymer concentration in the final immunological or vaccine composition can range between 0.01 and 1.5% w/v, 0.05 to 1% w/v or 0.1 to 0.4% w/v.
The cytokine or cytokines (5) can be in protein form in the immunological or vaccine composition, or can be co-expressed in the host with the immunogen or immunogens or epitope(s) thereof. Preference is given to the co-expression of the cytokine or cytokines, either by the same vector as that expressing the immunogen or immunogens or epitope(s) thereof, or by a separate vector thereof.
The invention comprehends preparing such combination compositions; for instance by admixing the active components, advantageously together and with an adjuvant, carrier, cytokine, and/or diluent.
Cytokines that may be used in the present invention include, but are not limited to, granulocyte colony stimulating factor (G-CSF), granulocyte/macrophage colony stimulating factor (GM-CSF), interferon α (IFNα), interferon β (IFNβ), interferon γ, (IFNγ), interleukin-1α (IL-1α), interleukin-1β (IL-1β), interleukin-2 (IL-2), interleukin-3 (IL-3), interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-6 (IL-6), interleukin-7 (IL-7), interleukin-8 (IL-8), interleukin-9 (IL-9), interleukin-10 (IL-10), interleukin-11 (IL-11), interleukin-12 (IL-12), tumor necrosis factor α (TNFα), tumor necrosis factor β (TNFβ), and transforming growth factor β (TGFβ). It is understood that cytokines can be co-administered and/or sequentially administered with the immunological or vaccine composition of the present invention. Thus, for instance, the vaccine of the instant invention can also contain an exogenous nucleic acid molecule that expresses in vivo a suitable cytokine, e.g., a cytokine matched to this host to be vaccinated or in which an immunological response is to be elicited (for instance, an avian cytokine for preparations to be administered to an avian).
In another embodiment, the composition of the present invention may be prepared using the chemical or physical procedure as described by Stauffer et al. (Recent patents on Anti-Infective Drug Discovery, 1, 291-296, 2006). Some of the inactivation techniques are summarized in the table below.












Chemical
Physical
Combined







Ascorbic Acid

Ascorbic Acid + UV


b-Propiolactone
Heat
Beta Propiolactone + UV


b-aminophenylketone
Pressure
Formalin + Heat


diethylpyrocarbonate
UV
Formalin + UV


Ethylenimine
Non Ionic
Heat + Low Pressure


Formalin/Formaldehyde
Detergents
Pressure + Heat or Cold


Phenol

Psoralen + UV









In one embodiment, the administration of the vaccine is to an avian, such as chickens, ducks, geese, turkeys, guinea fowl, partridges or ostriches. Chickens include, but are not limited to commercial layers, breeders, broilers, fancy chickens, and game hens. Ducks include, but are not limited to, Pekin ducks, Muscovy ducks, mule ducks and wild ducks. In an embodiment wherein the avian is a duck or avian larger than a chicken, larger doses may be contemplated. For example, in an embodiment wherein the administration is by eye drop, a dose approximating about 1 chicken dose, 2 chicken doses, 3 chicken doses, 4 chicken doses, 5 chicken doses, 6 chicken doses, 7 chicken doses, 8 chicken doses, 9 chicken doses and advantageously 10 chicken doses with the dosage up to about 20 to up to about 100 chicken doses if needed. For ease of reference, 5.5 log10 50% Egg Infective Dose (EID50) is approximately 1 chicken dose.
In another embodiment, the dosage may be in mean embryo infectious doses (EID50). In one embodiment, the dosage may be about 101 EID50, about 102 EID50, 103 EID50, about 104 EID50, about 105 EID50, about 106 EID50, about 107 EID50, or about 108 EID50.
The immunological composition and/or vaccine according to the invention comprise or consist essentially of or consist of an effective quantity to elicit a protective or therapeutic response of one or more expression vectors and/or polypeptides as discussed herein; and, an effective quantity can be determined from this disclosure, including the documents incorporated herein, and the knowledge in the art, without undue experimentation.
Advantageously, when the antigen is hemagglutinin, the dosage is measured in hemagglutination units (HAUs) or in micrograms. In an advantageous embodiment, the dosage may be about 100 hemagglutination units (HAU)/dose, about 1000 HAU/dose or about 10000 HAU/dose. In certain embodiments, the dosage is between 1 and 100 μg. The dosage volume may be between about 0.02 ml and 2 ml, advantageously between 0.03 ml and 1 ml, more advantageously between 0.03 ml and 0.5 ml and in an especially advantageous embodiment, the volume may be about 0.03 ml to about 0.3 ml.
The vaccines of the present invention may be administered to avian in ovo, via drinking water, sprays, aerosols, intranasal instillation, eye drop, beak-dipping, by wing-web stabbing, transdermal, subcutaneous or intramuscular injection. Advantageously, the vaccines are administered by subcutaneous, in ovo, eye drop, spray or drinking water.
In yet another embodiment, the vaccine may be administered in ovo 1 to 3 days before hatching, or to a 1 day old, 2 day old, 3 day old, 4 day old, 5 day old, 6 day old, 7 day old, 8 day old, 9 day old, 10 day old, 11 day old, 12 day old, 13 day old, 14 day old, 15 day old, 16 day old, 17 day old, 18 day old, 19 day old, 20 day old or 21 day old chicken.
In one embodiment of the invention, a prime-boost regimen can be employed, which is comprised of at least one primary administration and at least one booster administration using at least one common protein, polypeptide, antigen, epitope or immunogen. The immunological composition or vaccine used in primary administration is different in nature from those used as a booster. However, it is noted that the same composition can be used as the primary administration and the boost. This administration protocol is called “prime-boost”.
In another aspect of the prime-boost protocol of the invention, a composition comprising the engineered avian influenza Avinew NDV vaccine or composition is administered followed by the administration of vaccine or composition comprising a recombinant viral vector that contains and expresses an avian influenza antigen in vivo, or an inactivated viral vaccine or composition comprising the avian influenza antigen, or a vaccine or composition comprising an avian influenza subunit (protein), or a DNA plasmid vaccine or composition that contains or expresses an avian influenza antigen. Likewise, a prime-boost protocol may comprise the administration of vaccine or composition comprising a recombinant viral vector that contains and expresses an avian influenza antigen in vivo, or an inactivated viral vaccine or composition comprising the avian influenza antigen, or a vaccine or composition comprising an avian influenza subunit (protein), or a DNA plasmid vaccine or composition that contains or expresses an avian influenza antigen, followed by the administration of a composition comprising the engineered avian influenza Avinew NDV vaccine or composition. It is further noted that both the primary and the secondary administrations may comprise the composition comprising the engineered avian influenza Avinew NDV vaccine or composition.
A prime-boost protocol comprises at least one prime-administration and at least one boost administration using at least one common antigen. The vaccine or composition used in prime-administration may be different in nature from those used as a later booster vaccine or composition. The prime-administration may comprise one or more administrations. Similarly, the boost administration may comprise one or more administrations.
The various administrations are preferably carried out about 1 to about 6 weeks apart, or about 2 to about 4 weeks apart. Repeated booster every 2 to 6 weeks or an annual booster is also contemplated. The animals are preferably at least one day old at the time of the first administration.
The immunological composition and/or vaccine contains per dose from about 104 to about 1011, advantageously from about 105 to about 1010 and more advantageously from about 106 to about 109 viral particles of recombinant adenovirus expressing an influenza antigen, epitope or immunogen. In the case of immunological composition and/or vaccine based on a poxvirus, a dose can be between about 102 pfu and about 109 pfu. The immunological composition and/or vaccine contains per dose from about 102 to about 107, advantageously from about 103 to about 105 pfu of poxvirus or herpesvirus recombinant expressing the influenza antigen, epitope or immunogen.
In an embodiment wherein the avian immunological composition or vaccine is an inactivated avian virus, the inactivated avian virus may be derived from various seed viruses used in the production of the oil-emulsion vaccines may include Ulster 2C, B1, LaSota or Roakin. An inactivated avian influenza virus may also be classical inactivated (whole virus beta-propiolactone (BPL)-inactivated vaccine (H5N9-It) containing the H5N9 Eurasian isolate A/chicken/Italy 22A/98 propagated on embryonated SPF eggs. Other inactivated vaccines, adjuvanted, include commercially available whole virus preparations (Fort Dodge Animal Health, Intervet International, Merial Italia) based on field viruses of subtypes H5N2 and H5N9 or a recombinant H5N3 virus derived by genetic engineering (the latter contains a modified HA gene of A/chicken/Vietnam/C58/04 (H5N1), the neuraminidase gene of A/duck/Germany/1215/73 (H2N3) and the internal genes of A/PR/8/34 (H1N1).
The viral vector may be an attenuated avipox expression vector. In one embodiment, the avipox expression vector may be a fowlpox vector, for example, TROVAC®. In another embodiment, the avipox expression vector may be a canarypox vector, for example, ALVAC®. The influenza antigen, epitope or immunogen may be a hemagglutinin, such as H5. The fowlpox vector may be vFP89 (see, US 2008/0107681 and US 2008/0107687) or vFP2211 (see, US 2008/0107681 and US 2008/0107687). The canarypox vector may be vCP2241 (see, US 2008/0107681 and US 2008/0107687). Other viruses that may be used in methods of the invention include, but are not limited to, vaccinia viruses, such as an attenuated vaccinia virus, for instance NYVAC, adenoviruses and herpesviruses.
The efficacy of the vaccines may be tested about 2 to 4 weeks after the last immunization by challenging animals, such as an avian, with a virulent strain of influenza, for example, the influenza H5N1, H5N8 or H5N9 strains. Both homologous and heterologous strains may be used for challenge to test the efficacy of the vaccine. The animal may be challenged by spray, intra-nasally, eye drop, oculo-nasal, IM, intra-tracheally, and/or orally. The challenge viral may be about 103 to about 108 EID50 in a volume depending upon the route of administration. For example, if the administration is by spray, a virus suspension is aerosolized to generate about 1 to 100 μm droplets, if the administration is intra-nasal, intra-tracheal or oral, the volume of the challenge virus is about 0.05 to about 5 ml. The dose volume of compositions for target species, e.g., the dose volume of avian compositions, may be about 50 μl for in ovo, about 20 to about 50 μl for eye drop, about 0.25 ml to about 1 ml for spray. Animals may be observed daily for 14 days following challenge for clinical signs and mortality. In addition, the groups of animals may be euthanized and evaluated for pathological findings. Oropharyngeal, tracheal or cloacal swabs may be collected from all animals post challenge for virus detection. The presence or absence of viral antigens in tissues may be evaluated by immunohistochemistry, viral isolation or titration, or nucleic acid detection such as reverse-transcriptase polymerase chain reaction (RT-PCR). Blood samples may be collected post-challenge and may be analyzed for the presence of anti-influenza H5N1 virus-specific antibody.
It should be understood by one of skill in the art that the disclosure herein is provided by way of example and the present invention is not limited thereto. From the disclosure herein and the knowledge in the art, the skilled artisan can determine the number of administrations, the administration route, and the doses to be used for each immunization protocol, without any undue experimentation.
The present invention contemplates at least one administration to an animal of an efficient amount of the therapeutic composition made according to the invention. This administration may be via various routes including, but not limited to, intramuscular (IM), intradermal (ID) or subcutaneous (SC) injection or via intranasal, in ovo, or oral administration. The therapeutic composition according to the invention can also be administered by a needleless apparatus (as, for example with a Pigjet, Dermojet, Biojector, Vetjet or Vitajet apparatus (Bioject, Oregon, USA)). In one embodiment, the animal is an avian.
Another embodiment of the invention is a kit for performing a method of inducing an immunological or protective response against influenza in an animal comprising a recombinant NDV immunological composition or vaccine or an inactivated influenza immunological composition or vaccine and instructions for performing the method of delivery in an effective amount for eliciting an immune response in the animal.
The invention is further illustrated by the following non-limiting examples.
EXAMPLES
Construction of DNA inserts, plasmids and recombinant viral vectors was carried out using the standard molecular biology techniques described by J. Sambrook et al. (Molecular Cloning: A Laboratory Manual, 2nd Edition, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., 1989).
Example 1
Development of Reverse Genetics of the AVINEW® (NDV) Strain and Generation of NDV Mutants Expressing Heterologous Genes
The aim of this Example was to develop the reverse genetics of the AVINEW NDV strain to generate engineered NDV mutants expressing heterologous genes.
The NDV is a negative RNA virus that contains 6 major genes (NP, P, M, F, HN and L) as depicted in FIG. 1A. The generation of genetically modified NDV virus needs a reverse genetics system. A reverse genetic system has been developed by Applicants based on the AVINEW vaccine strain of NDV. This system permits generation of modified Newcastle Disease Viruses expressing a foreign gene, such as the hemagglutinin (HA) of influenza as depicted in FIG. 1B.
Example 1.1
Cloning of the Whole AVINEW NDV Genome into a Transcription Plasmid and Sequence Analysis
For the purpose of sequencing the genome of AVINEW NDV strain, the whole genome of the AVINEW strain needs to be cloned into a plasmid that is designated as a “transcription plasmid” (see 1. in FIG. 1C). The transcription plasmid allows generating a positive RNA corresponding to the entire genome of the AVINEW strain of NDV. The strategy for AVINEW genome cloning by successively joining a set of 10 overlapping cDNAs fragments amplified from the AVINEW extracted RNA by reverse transcriptase polymerase chain reaction (RT-PCR) is shown in FIG. 2. This final plasmid designated pIV029 (see FIG. 3) contains the complete genome sequence of AVINEW that is under the control of T7 RNA polymerase transcription signals (T7 promoter located upstream) and is terminated by Hepatitis Delta Virus (HDV) ribozyme that is used to cleave the RNA at the authentic NDV genomic terminus followed by T7 terminator. Restriction sites were inserted between P and M genes to permit the insertion of a transgene (see FIGS. 2 & 3).
The entire genome of the AVINEW® strain was sequenced. The AVINEW® genome is 15186 bp in length which is, as expected based on the nucleocapsid protein binding motif, a multiple of 6 nucleotides.
The annotated sequence of the insert of pIV029 is presented in FIGS. 4A-40 and a plasmid map is presented in FIG. 3. In FIGS. 4A-4O, the 6 open reading frames (ORF) of the Avinew strain (NP, P, M, F, HN and L) are translated into their amino acid sequence. Each ORF is flanked by “gene start” upstream and “gene stop” downstream sequences that are indicated with GS and GE. The T7 promoter and T7 terminator sequences are indicated.
Example 1.2
Construction of the Expression Plasmids Containing the NP, P and L Genes of AVINEW NDV
In the reverse genetics system, plasmids designated “expression plasmids” that encode the nucleocapsid (NP), phosphoprotein (P) and large polymerase protein (L) under the control of the T7 RNA polymerase promoter need to be constructed (see FIG. 1C). These three proteins are associated with viral RNA to form the RiboNucleoProteins (RNPs) which represent the smallest infectious unit of NDV. The complex composed of NP, P, and L proteins presents RNA dependent RNA polymerase activity.
The expression plasmids pIV32 (FIG. 5), pIV33 (FIG. 6) and pIV34 (FIG. 7) were constructed and contain the NP, P and L genes of AVINEW, respectively, under the control of the T7 RNA polymerase promoter and Foot and Mouth Disease Virus (FMDV) Internal Ribosome Entry Site (IRES).
Example 1.2.1
Construction of the Expression Plasmids pIV32 Containing the NP Gene of AVINEW NDV
The map of expression plasmid pIV32 is shown in FIG. 5. This plasmid contained the nucleotide sequence encoding the open reading frame (ORF) of the nucleocapsid (NP) gene of the Newcastle Disease Virus AVINEW® vaccine strain under the control of T7 RNA polymerase promoter and Foot and Mouth Disease Virus (FMDV) Internal Ribosome Entry Site (IRES). The NDV ORF NP (1467 bp, SEQ ID NO:2) encodes a 489 amino acid polypeptide (SEQ ID NO:3). Protein NP is the major structural component of the nucleocapsid. The protein is approximately 58 kDa. Total of 2600 NP molecules tightly encapsidate the genomic RNA. NP interacts with several other viral encoded proteins, all of which are involved in controlling replication (NP-NP, NP-P, NP-(PL), and NP-V). NP associated with NDV genomic RNA and proteins P and L constitute the NDV ribonucleoprotein (RNP) complex, which is the infectious form of NDV genome.
Example 1.2.2
Construction of the Expression Plasmid pIV33 Containing the P Gene of AVINEW NDV
The map of expression plasmid pIV33 is shown in FIG. 6. This plasmid contained the nucleotide sequence encoding the ORF of the phosphoprotein (P) gene of the Newcastle Disease Virus AVINEW® vaccine strain under the control of T7 RNA polymerase promoter and Foot and Mouth Disease Virus (FMDV) Internal Ribosome Entry Site (IRES). This plasmid was designed for generation of recombinant NDV AVINEW® as a vaccine vector using reverse genetic methodology.
The NDV ORF P (1185 bp, SEQ ID NO:4) encodes a 395 amino acid polypeptide: the structural phosphoprotein (P) (SEQ ID NO:5). This protein has a molecular weight of 53 to 56 kDa as determined by SDS-PAGE. Protein P is essential for the activity of the RNA polymerase complex, which it forms with the large subunit L. Although all the catalytic activities of the polymerase are associated with the L subunit, its function requires specific interactions with P. P associated with proteins L and NP and with NDV genomic RNA constitute the NDV ribonucleoprotein (RNP) complex, which is the infectious form of NDV genome.
In addition, the P gene encodes protein V (unknown function) with an apparent molecular weight of 36 to 38 kDa on SDS-PAGE. The P and V proteins share the same amino terminus, but they diverge at their C-termini. This difference is generated by an RNA-editing mechanism in which one non-templated G residue is inserted into P-gene-derived mRNA. The unedited transcript codes for the P protein while the edited transcript codes for the V protein. Being phosphoproteins, both P and V are rich in serine and threonine residues over their whole lengths. In addition, the V protein is rich in cysteine residues at the C-terminius. As well, the P gene encodes protein W (unknown function), with an apparent molecular weight of 28 to 33 kDa on SDS-PAGE. This protein is also produced by a RNA-editing mechanism in which two instead of one non-template G residues are inserted into P-gene-derived mRNA.
Example 1.2.3
Construction of the Expression Plasmids pIV034 Containing the L Gene of AVINEW NDV
The map of expression plasmid pIV34 is shown in FIG. 7. This plasmid contained the nucleotide sequence encoding the ORF of the large polymerase protein (L) gene of the Newcastle Disease Virus AVINEW® vaccine strain under control of T7 RNA polymerase promoter and Foot and Mouth Disease Virus (FMDV) Internal Ribosome Entry Site (IRES). This plasmid is designed for generation of recombinant NDV AVINEW® as a vaccine vector using reverse genetic methodology.
The NDV L gene (6612 bp, SEQ ID NO:12) encodes a 2204 amino acid polypeptide, which is the L protein (SEQ ID NO:13). Paramyxoviridae, like other non-segmented negative strand RNA viruses, have an RNA-dependent RNA polymerase composed of two subunits, a large protein L and a phosphoprotein P. The L protein confers the RNA polymerase activity on the complex while the P protein acts as a transcription factor. Protein L associated with proteins P and NP and with NDV genomic RNA constitutes the NDV ribonucleoprotein (RNP) complex, which is the infectious form of NDV genome.
Example 1.3
Construction of the Expression Plasmid Allowing Expression of the T7 RNA Polymerase
The reverse genetics system requires the T7 RNA polymerase to be expressed in cells where the NDV virus will be regenerated (see FIG. 1C). Different systems can be used to express the T7 RNA polymerase including the use of a recombinant virus (e.g. an avipox) as a vector, the use of cells that constitutively express the enzyme or the transient expression using an expression plasmid. The latter solution was chosen and an expression plasmid (designated pNS151) encoding the T7 RNA polymerase under the HCMV IE promoter was constructed. The T7 RNA polymerase allows not only the transcription/expression of NP, P and L proteins from the expression plasmids described above, but also transcribes the NDV genome (present in the transcription plasmid) into a positive sense RNA. A map of the plasmid is shown in FIG. 8.
Example 1.4
Recovery of NDV Virus Using the Reverse Genetics System
The above-described five plasmids (one transcription plasmid containing the NDV genome, three expression plasmids expressing NDV NP, P and L, and the expression plasmid expressing the T7 polymerase) were co-transfected together into Chinese hamster ovary (CHO) cells. FIG. 1C is a schematic representation that explains the mechanism of the reverse genetics system. As the scheme shows that upon entry of the cell, T7 RNA polymerase is expressed which then transcribe the NDV genome from the transcription plasmid into a positive sense RNA (RNA(+)) genome as well as the NP, P and L genes from the individual expression plasmids. The NP, P and L protein transcripts are then translated as expressed NP, P and L proteins which then assemble and form RNPs with genomic RNA(+). This RNP complex synthesizes a negative sense RNA genome (RNA(−)) which then initiates the normal replication cycle of NDV virus facilitating the generation of infectious particles. Trypsin or other exogenous proteases such as provided by egg allantoic clued may be added in the medium to cleave the F protein of generated viruses.
Using this system, the infectious particles of AVINEW NDV were successfully obtained. Briefly, the different plasmids (pIV029, pIV32, pIV33, pIV034 and pNS151) required were transfected into CHO cells. After 72 hours, the CHO supernatants were inoculated in 10-day-old embryonated eggs to amplify the virus. After 3 days, the allantoic fluid was harvested and checked for hemagglutination activity (HA) using chicken red blood cells. The obtained reverse genetics AVINEW mutant was designated vAVW01. It contains the same sequence as the AVINEW parental virus except for the two unique restriction sites (PacI & FseI) introduced between the P and M genes (see FIG. 2).
Example 1.5
Generation of NDV Virus Expressing Foreign Genes Using the Reverse Genetics System
To generate modified NDV viruses expressing a foreign antigen, a locus of insertion needs to be chosen. Different loci can be chosen including upstream of NP gene and between 2 genes. In this example, the site between the P and M genes of AVINEW® NDV was chosen to insert a foreign gene as shown in FIG. 9. The foreign gene needs to be inserted along with the required “start” and “stop” transcription sequences and the number of inserted nucleotides needs to be designed such that the total number of nucleotides in the modified NDV genome remains a multiple of six.
This example details the generation of AVINEW mutants expressing the hemagglutinin (HA) gene from avian influenza. The HA gene was first inserted into a transfer plasmid that allows the insertion of the foreign gene and flanking sequences into the PacI and FseI unique restriction sites of pIV029. The structure of the transfer plasmid is depicted in FIG. 9 (within the box). It contains from left to right the PacI site, the 3′UTR of P downstream from the PacI site, the gene end (or STOP) sequence of P, the P/M intergene, the gene start (or START) sequence of M, the 5′ UTR of M, multiple cloning sites, the 3′UTR of P (upstream from the PacI site) and the FseI site. The HA gene was cloned into the multiple cloning site of the transfer plasmid as depicted in FIG. 9 and then the whole PacI/FseI insert was cloned into the same restriction sites of pIV029 (FIG. 3) to generate the transcription plasmid containing the foreign gene. An example (pIV039) of such transcription plasmid is shown in FIG. 10. In this example, a synthetic gene coding for the amino acid sequence of the HA gene of the A/chicken/Indonesia/7/2003 highly pathogenic H5N1 avian influenza virus modified at the cleavage site was inserted into the transcription plasmid.
The transcription plasmid pIV039 was used together with the 4 additional expression plasmids required for the generation of AVINEW mutants by reverse genetics (see example 1.4) to generate an AVINEW® mutant designated vAVW02 expressing the HA gene from the A/chicken/Indonesia/7/2003 highly pathogenic (HP) H5N1 avian influenza (AI) virus.
The same method was used to generate different AVINEW mutants expressing an HA gene from different HPAI H5N1 or low pathogenic AI (LPAI) H9N2. The sequences of the insert HA genes from different H5N1 and H9N2 AI isolates are assigned SEQ ID NO as shown in FIG. 12, and both the DNA and protein sequences are included in the Sequence Listing. The content of the electronically submitted Sequence Listing filed with the application is incorporated herein by reference in its entirety.
The procedure described above was successfully used for the recovery of infectious AVINEW mutants expressing an HA gene from different HPAI H5N1 or low pathogenic AI (LPAI) H9N2 (see Table 1).







TABLE 1







Different Avinew mutants generated and expressing a synthetic HA


gene from different avian influenza isolates. All HA genes from HPAI


H5N1 were mutated at the cleavage site in order to match the


sequence of the cleavage site of LPAI H5 isolates













HA subtype


Name
Insert
Avian influenza strain
and clade of AI





vAVW01
—
—
—


vAVW02
H5
A/chicken/Indonesia/7/2003
H5N1 clade 2.1


vAVW03
H5
A/turkey/Turkey/1/2005
H5N1 clade 2.2


vAVW04
H5
A/Duck/Laos/3295/2006
H5N1 clade 2.3


vAVW05
H9
A/chicken/Iran/AV1221/1998
H9N2


vAVW06
H9
A/chicken/Iran/AV1221/1998
H9N2




(mutated)


vAVW09
H5
A/chicken/WestJava/PWT-WIJ/2006
H5N1 clade 2.1









Example 1.6
Production and Characterization of NDV Virus Expressing Foreign Genes Using the Reverse Genetics System
All engineered AVINEW mutants were amplified by subsequent passage on embryonated eggs and characterized. The recombinant viruses grew to titers similar to the original AVINEW® virus (8 to 10 log 10 EID50/ml) suggesting that the foreign gene insertion did not have a significant impact on the replication of the virus in embryonated eggs. An example of infectious titers obtained in the 2nd or 3rd passage on embryonated eggs is shown in Table 2.
Expression of the H5 transgene was confirmed by indirect immunofluorescence on infected CHO cells and by immunoblot (Western Blot or WB) on allantoic fluids and on CHO infected cells lysates (see FIGS. 11A and 11B for vAVW02 as an example). The electrophoretic profile of the H5 was as expected. Due to the presence of proteases in the allantoic fluid, the proper HA cleavage products, namely HA1 (50 kDa) and HA2 (28 kDa), were detected. In CHO cells infected (in absence of trypsin) with the egg-grown viruses, applicants detected only the HA0 form (75 kDa) (FIG. 11A).
The expression of the foreign HA protein at the surface of the NDV virion was confirmed by immunoelectron microscopy using vAVW02 as an example (see FIG. 2B).







TABLE 2







Yield and control of expression of Avinew mutants generated and


expressing a synthetic HA gene from different avian influenza isolates.















HA expression






detected by WB in





HA expression
allantoic fluid from




Titers in
detected by IF
infected eggs or in


Name
Insert
EID50/ml
in CHO cells
CHO-infected lysate





vAVW01
—
9.8
Negative
Negative


vAVW02
H5
9.1
Positive
Positive


vAVW03
H5
8.2
Positive
Positive


vAVW04
H5
8.7
Positive
Positive


vAVW05
H9
8.8
Positive
Not tested


vAVW06
H9
9.2
Positive
Not tested


vAVW09
H5
9.1
Positive
Not tested









Example 2
Chicken Study 1: Protection Against Newcastle Disease and ND and AI HI Titers Induced by Engineered AVINEW Mutants in Chickens
The aim of this study was to verify that the insertion of a foreign gene into the genome of the AVINEW strain did not decrease the ability to protect chickens against Newcastle disease (ND). The vaccination scheme is shown in the upper panel of FIG. 3A. The percentage of protection induced by the AVINEW vaccine and 2 engineered AVINEW mutants (vAVW01 that does not contain any insert (see Table 1) and vAVW03 that contains a HPAI H5N1 HA insert) is shown in the lower table of FIG. 3A. Similar levels of ND protection were induced by the two tested doses of the 3 vaccines demonstrating that, in the tested conditions, there is no negative impact of the HA insertion on the ability of the vector to protect against a velogenic NDV challenge with the Herts33 strain.
Example 3
Protection Against H5N1 HPAI Induced by Engineered AVINEW Mutants in SPF Chickens with or without Maternally-Derived Antibodies (MDA) Against NDV and/or AI
Example 3.1
Chicken Study 2: Protection Against an Hungarian (2006) H5N1 HPAI Isolate Induced by One Administration of Engineered AVINEW Mutants in SPF Chickens
The efficacy of the engineered AVINEW mutant vAVW03 against an HPAI H5N1 challenge was evaluated in SPF (specific pathogen free) chickens. Eight one-day-old SPF chickens were vaccinated with 105 EID50 by eye drop (ED) and intra-nasal (IN) route (D0). The H5N1 challenge (6 log 10 of the H5N1 clade 2.2 A/duck/Hungary/11804/2006 isolate per bird) was performed 4 (D28) and 6 (D42) weeks after vaccination. Chickens were followed up for 2 weeks after challenge. Results are shown in Table 3 and Table A.







TABLE 3







Chicken study 2: Results of clinical protection from a


vaccination-challenge study evaluating the protective efficacy


induced by the engineered vAVW03 mutant against an


HPAI H5N1 (A/duck/Hungary/11804/2006) challenge in SPF chicks











Vaccination (D0)
H5N1
Protection











Group
Vaccine
Dose (EID50)
Challenge
(MTD)a





1
—
—
D28
0% (3.0)


2
vAVW03
5 log10
D28
100%


3
—
—
D42
0% (3.5)


4
vAVW03
5 log10
D42
75% (8.0) 





aMTD: mean time to death in days













TABLE A







Chicken study 2: Results of protection against shedding from a vaccination-


challenge study evaluating the protective efficacy induced by the


engineered vAVW03 mutant against an HPAI H5N1 (A/duck/Hungary/


11804/2006) challenge in SPF chicks










Vaccination (D0)













Dose
H5N1
Oral sheddinga
Cloacal sheddinga
















Group
Vaccine
(EID50)
Chall.
2 dpc
4 dpc
7 dpc
2 dpc
4 dpc
7 dpc





1
—
—
D28
8/8
—
—
8/8
—
—


2
vAVW03
5 log10
D28
3/8
2/8
2/8
0/8
0/8
0/8


3
—
—
D42
8/8
—
—
7/8
—
—


4
vAVW03
5 log10
D42
4/8
4/8
2/8
0/8
2/8
1/8





aShedding was evaluated using real time PCR from oral and cloacal swabs taken 2, 4 and 7 days post-challenge (dpc)






Full and partial (75%) clinical protections were induced at D28 and D42, respectively. The number of chickens shedding detectable amount of challenge virus was reduced in the vaccinated groups. Furthermore the levels of shedding in the vaccinated groups (2 and 4) at 2 dpc were more than 3 log 10 and about 2 log 10 lower than that in the control groups after challenge at D28 and D42, respectively. Altogether, these results indicate that the Avinew vector expressing an HPAI HA gene is protective in SPF chickens.
Example 3.A
Chicken Study A: Protection Against an Egyptian (2006) H5N1 HPAI Isolate Induced by One Administration of Engineered AVINEW Mutants in SPF Chickens
The efficacy of the engineered AVINEW mutant vAVW03 against an Egyptian HPAI H5N1 challenge was evaluated in SPF (specific pathogen free) chickens. Ten one-day-old SPF chickens were vaccinated with 106 EID50 by eye drop (ED) and intra-nasal (IN) route (D0). The H5N1 challenge (6 log 10 of the H5N1 clade 2.2 A/chicken/Egypt/06959-NLQP/2006 isolate per bird) was performed 3 (D21) weeks after vaccination. Chickens were followed up for 2 weeks after challenge. Results are shown in Table B.







TABLE B







Chicken study A: Results of clinical protection from a


vaccination-challenge study evaluating the protective efficacy


induced by the engineered vAVW03 mutant against an HPAI H5N1


(A/chicken/Egypt/06959-NLQP/2006) challenge in SPF chicks










Vaccination (D0)
Protection after












Group
Vaccine
Dose (EID50)
challenge at D21
















1
—
—
0%



2
vAVW03
6 log10
90%










Excellent (90%) clinical protections were induced at D21 against this Egyptian HPAI H5N1 isolate confirming that the Avinew vector expressing an HPAI HA gene induces protection in SPF chickens.
Example 3.B
Chicken Study B: Protection Against an Hungarian (2006) H5N1 HPAI Isolate Induced by 1 or 2 Administrations of an Engineered AVINEW Mutants or a Prime-Boost Regimen in SPF Chickens
The efficacy of the engineered AVINEW mutant vAVW03 after one, two administrations or a prime-boost regime with an inactivated vaccine against a Hugarian (2006) HPAI H5N1 challenge was evaluated in SPF (specific pathogen free) chickens. Eight one-day-old SPF chicks per group were vaccinated with 105 EID50 by eye drop (ED) and intra-nasal (IN) route at D0 (groups 2, 3 and 4) and at D14 (group 3). Chickens from group 3 received an inactivated vaccine made with the H5N9 A/chicken/Italy/A22/1998 LPAI isolate (0.5 ml/chick). The H5N1 challenge (6 log 10 of the H5N1 clade 2.2 A/duck/Hungary/11804/2006 isolate per chicken) was performed 4 (D42) weeks after the second vaccination. Chickens were followed up for 2 weeks after challenge. Results are shown in Table C.







TABLE C







Chicken study B: Results of protection from a vaccination-challenge


study evaluating the protective efficacy induced by different


vaccination scheme including the vAVW03 mutant against an


HPAI H5N1 (A/duck/Hungary/11804/2006) challenge in SPF chickens.












# birds





protected/




total
Number of chickens/




(MTD*)
total shedding virus




after
(real time RT-PCR)



Vaccination at
challenge
2dpc-4 dpc**












Group
D0
D14
at D42
Oral swab
Cloacal swab





1
—
—
0/8 (3.8)
8/8-0/0
8/8-0/0


2
vAVW03
—
7/8 (6)
5/8-2/8
0/8-0/8


3
vAVW03
vAVW03
7/8 (6)
3/8-2/8
0/8-0/8


4
vAVW03
Inact.
8/8
0/8-1/8
0/8-0/8




H5N9**





*MTD, mean time to death in days


**dpc, day post-challenge


***the inactivated (or killed) AI H5N9 vaccine was prepared with the H5N9 A/chicken/Italy/A22/1998 LPAI isolate






Excellent clinical protections were induced in the 3 vaccinated groups. Reduction in the number of shedding chickens as well as in the level of shedding of challenge virus was also induced by vaccination. The best protective performances were obtained in chickens from group 4 that received the prime-boost regimen. These results confirm that the Avinew vector expressing an HPAI HA gene induces protection in SPF chickens and indicates that the level of protection may be improved by a prime-boost strategy.
Example 3.C
Chicken Study C: Protection Against a Variant Egyptian (2008) H5N1 HPAI Isolate Induced by Different Vaccination Schemes Including an Engineered AVINEW Mutants in SPF Chickens
The efficacy of the engineered AVINEW mutant vAVW03 included in different vaccination schemes (see Table D) against an HPAI H5N1 challenge using a variant Egyptian isolate from 2008 (A/chicken/Egypt/1709-6/2008) was evaluated in one-day-old SPF (specific pathogen free) chickens. The vaccination scheme is shown in Table D. The vAVW03 vaccine was administered at a dose of 106 EID50/100 μL by the intra-ocular (504) and intra-nasal (50 μL) routes at D0 (groups 2 and 3) and at D14 (groups 2 and 4). Chickens from group 3 received an inactivated vaccine made with the reverse genetics H5N1 strain that contains the HA (modified at the cleavage site) and NA from the H5N1 clade 2.3 A/duck/Anhui/1/2006 LPAI isolate (0.5 ml/chick). Chickens from group 4 received at D0 a commercial dose (approximately 3.5 log 10 TCID50/200 μL) by the subcutaneous route (nape of the neck) of the fowlpox recombinant vFP89 expressing the HA from the H5N8 HPAI A/turkey/Ireland/1378/1983 isolate (TROVAC-AIV H5 vaccine, see US 2008/0107681 and US 2008/0107687) diluted in Marek's disease vaccine diluent (Merial's proprietary material). The H5N1 challenge (5 log 10 of the H5N1 clade 2.2 A/chicken/Egypt/1709-6/2008 isolate per bird) was performed 2 weeks after the second vaccination (D28). Chickens were followed up for 10 days after challenge. Results are shown in Table D.







TABLE D







Chicken study C: Results of clinical protection from a


vaccination-challenge study evaluating the protective efficacy


induced by different vaccination scheme including the vAVW03


mutant against an HPAI H5N1 (A/chicken/Egypt/1709-6/2008)


challenge in SPF chickens.














Mean ±






SD HI





titers
# chickens





(log2)
protected/total





using
(MTD**)



Number

H5N1
after



of
Vaccination at
antigen*
challenge at












Group
chickens
D0
D14
D28
D28





1
10
—
—
—
 0/10 (3)


2
14
vAVW03
vAVW03
3.3 ± 0.7
13/14 (6)


3
14
vAVW03
Inact. Re5
9.1 ± 1.5
14/14


4
14
vFP89
vAVW03
4.4 ± 1.3
14/14





*the H5N1 antigen was prepared from the A/turkey/Turkey/1/2005 antigen; SD standard deviation


**MTD, mean time to death in days






The HI titers induced by the different vaccination schemes are shown in Table D. As expected, the higher HI titers were obtained in group 3 after the boost with an inactivated vaccine. Excellent clinical protections (93-100%) were induced in the 3 vaccinated groups. It's worth mentioning that the A/chicken/Egypt/1709-6/2008 isolate (HA protein sequence available in GenBank: ACD65000.1) is one of the H5N1 antigenic variants that emerged recently in Egypt and against which commercial inactivated H5 vaccines provide less protection than against older Egyptian strains. These results confirm that the Avinew vector expressing an HPAI HA gene induces protection in SPF chickens against an antigenic variant H5N1 Egyptian isolate.
Example 3.2
Chicken Study 3: Protection Against H5N1 HPAI Induced by Engineered AVINEW Mutants in Chickens with and without NDV and/or AI MDA
The goal of the study was to evaluate the level of HPAI H5N1 protection induced by the AVINEW mutant vAVW03 expressing an H5N1 HPAI HA gene in SPF chickens and to evaluate the possible interference of maternally-derived antibodies (MDA) against the NDV vector and/or against AI.
In order to evaluate the effect of MDA on AI protection, SPF breeders had to be immunized with different vaccination schemes as shown in Table 4. There were 3 groups of breeders: the first group (G1) was vaccinated against NDV (3 administrations of AVINEW and 1 administration of inactivated (or killed) vaccine) and AI (3 administrations of an inactivated vaccine based on the H5N9 A/chicken/Italy/A22/1998 LPAI isolate); the second group (G4) was vaccinated against NDV only (same immunization scheme as group 1) and the third group (G5) was vaccinated with AI only (two administrations of an inactivated vaccine based on an H5N1 mutant containing the HA and NA genes from the A/goose/Guandong/1996 isolate) (see details in Table 4).







TABLE 4







Vaccination scheme of the SPF breeders used to produce


one-day-old chickens with ND and/or AI MDAs













MDA


Breeders
Breeders
Weeks
in the
















group
vaccines
0
3
4
6
8
9
16
progeny





G1
ND L + K*
L

L

L

K
H5N9 +



AI H5N9 K**

K

K


K
ND


G4
ND L + K
L

L

L

K
ND



—


G5
—







H5N1



AI H5N1 K***





K
K





*L = Live NDV vaccine AVINEW; K = killed NDV vaccine (Gallimune 407)


**the inactivated (or killed) AI H5N9 vaccine was prepared with the H5N9 A/chicken/Italy/A22/1998 LPAI isolate


***the inactivated (or killed) AI H5N1 vaccine was prepared with an AI mutant containing the HA and NA genes from the H5N1 A/goose/Guandong/1996 HPAI isolate






Chickens were hatched from eggs laid by these immunized breeders and the HPAI H5N1 efficacy induced by vAVW03 in these chicks with MDA was compared with that induced in SPF chickens without MDA.
FIG. 13 shows the mean NDV and AI HI titers (in log 2) observed in one-day-old chickens hatched from the immunized breeders described in Table 4. NDV titers were very high in both groups from ND-vaccinated breeders (G1 & G4). The AI HI titers measured with H5N1 clade 2.2 (A/duck/Hungary/11804/2006) and H5N9 (A/chicken/Italy/A22/1998) antigens were higher in the chicken progeny of G5 breeders vaccinated with an inactivated H5N1 vaccine. These results confirmed the presence of the expected MDA in the serums of day-old chicks hatched from the vaccinated SPF breeders.
FIG. 14 depicts a timeline for the immunization and challenge protocol of SPF chickens with or without MDA. One-day-old chickens from regular SPF flocks or from vaccinated SPF breeders were immunized by the oculonasal route with 105 EID50 of either vAVW03 expressing the HA gene from the A/turkey/Turkey/1/2005 HPAI H5N1 isolate (10 animals) or with vAVW01 that did not contain any HA insert and was used as a control (10 animals). Three weeks post-vaccination, all chickens were challenged with 6 log 10 of the HPAI H5N1 A/duck/Hungary/11804/2006 isolate by the intraocular route. Chickens were observed for clinical signs and mortality during two weeks after challenge. Table 5 summarizes the vaccination scheme and the avian influenza protection results.







TABLE 5







AI protection induced by an AVINEW® mutant (vAVW03)


expressing H5N1 HA in SPF chickens and chickens with various


MDAs



















% pro-


Group
MDA
Breeders
Vaccine
Mortality
MDT*
tection
















1
—
SPF
vAVW01
10/10 
3.8
0%


2
—
SPF
vAVW03
1/10
11
90%


3
H5N9 +
G1
vAVW01
7/10
7.3
30%



ND


4
H5N9 +
G1
vAVW03
2/9
10
78%



ND


5
ND
G4
vAVW01
10/10 
3.6
0%


6
ND
G4
vAVW03
0/10
—
100%


7
H5N1
G5
vAVW01
1/10
8
90%


8
H5N1
G5
vAVW03
0/10
—
100%





*MDT = mean death time in days






The rapid mortality (mean death time of 3.6-3.8 days) of chickens without AI MDA vaccinated with vAVW01 (Groups 1 and 5) validated the challenge (see Table 5 and FIG. 15). HPAI H5N1 protection level after 1 mucosal administration of vAVW03 in one-day-old SPF chickens protected 90% of the chickens. Surprisingly, all vAVW03-immunized chickens hatched from breeders (G4 in Table 4) vaccinated with NDV only (group 6) were protected from the HPAI challenge indicating that there was no anti-vector NDV MDA interference on the AI protection. The effect of AIV MDA is more difficult to assess since only 7 and 1/10 chickens died after challenge in the control groups (groups 3 and 7); however 7/9 birds vaccinated with vAVW03 (group 4) were protected indicating that protection can be induced in the presence of both NDV and AI MDAs. Vaccinated chickens that died after challenge died at a later time compared to unvaccinated birds (see Table 5 the mean death time and FIG. 15 for the kinetic of mortality). Table 6 shows the number of chickens positive for oral or cloacal shedding and FIG. 16 shows the kinetic of oral (16A) and cloacal (16B) shedding after challenge. The ratio between levels of shedding in vAVW01/vAVW03 is also shown in FIG. 16 for oral (16C) and cloacal (16D) swabs. The vAVW03-vaccinated chickens shed much lower virus and the number of positive swabs was lower after challenge compared with the vAVW01-vaccinated chickens.







TABLE 6







H5N1 shedding in the 8 tested groups was evaluated by


real time reverse transcriptase PCR (RRT-PCR) targeting


the matrix gene in oral and cloacal swabs at 2, 4, and 7 days


post H5N1 HPAI challenge (dpc).












Bird-
2dpc
4dpc
7dpc














Group
vaccine*
Oral
Cloacal
Oral
Cloacal
Oral
Cloacal





1
SPF-v01
6/6 
6/6 
NS
NS
NS
NS


2
SPF-v03
7/10
0/10
10/10
4/10
3/10
1/10


3
MDA+NDV-
9/9 
1/9 
2/2
1/2 
0/1 
0/1 



v01


4
MDA+NDV-
4/10
0/10
 6/10
0/10
2/10
1/10



v03


5
MDA+NDV-
8/10
1/10
9/9
4/9 
5/5 
1/5 



H5-v01


6
MDA+NDV-
4/10
0/10
 7/10
5/10
0/6 
1/6 



H5-v03


7
MDA+H5-
8/10
3/10
 8/10
4/10
5/10
1/10



v01


8
MDA H5-
7/10
0/10
 6/10
2/10
6/10
1/10



v03





*v01 = vAVW01 and v03 = vAVW03






FIG. 17 depicts the NDV MDA effect on vAVW03-induced MV HI titers (using the H5N1 clade 2.2 (A/duck/Hungary/11804/2006) and H5N9 (A/chicken/Italy/A22/1998) antigens) after vaccination (D21) and after challenge (D35). In the presence of NDV MDAs (NDV), on day 21 (after vaccination and before challenge), there were higher mean AIV HI titers after vaccination and a higher number of chickens with detectable HI titers against both antigens. On day 35 (after challenge), there was no AIV HI titer boost after AIV challenge in the progeny of breeders vaccinated with NDV only and 10/10 chickens were protected (versus 9/10 in SPF group). In SPF chickens with no MDA, the clear increase of AIV HI titers after challenge suggested that the challenge virus replicates somewhat in these chickens. The results suggest an unexpected better AIV antibody induction and protection in chickens with NDV MDAs.
FIG. 18 depicts NDV HI titers post-vaccination (D21). On Day 21, vAVW01-induced NDV titers were usually higher than those induced by vAVW03. On Day 21, there was no difference in chickens with (from G1 (H5+NDV) or G4 (NDV) breeders) or without (from SPF or G5 (H5N1) breeders) NDV MDA with respect to NDV HI titers, indicating that NDV MDAs did not interfere on vAVW01 or vAVW03-induced NDV HI titers.
Altogether the results of this study indicate clearly that one mucosal administration to one-day-old chickens of a relatively low dose (5 log 10 EID50) of the AVINEW engineered mutant vAVW03 induced an excellent level of protection against an HPAI H5N1 challenge. The presence anti-vector (NDV) MDA had no negative impact on AI protection. In contrast and surprisingly, the protection and AI antibody data suggest a better AI protection when NDV MDAs were present in the one-day-old chickens at the time of vAVW03 vaccination. These results also show that AI protection may be induced by vAVW03 in birds with both NDV and AI maternal antibodies.
Example 4
Protection Against H5N1 HPAI Induced by Engineered AVINEW Mutants in Ducklings
Ducks can be naturally infected with NDV and represents the reservoir for avian influenza A viruses. They may not necessarily show clinical signs after AI infection even with highly pathogenic strains but may transmit the virus to the chickens that are highly susceptible. That is why ducks are called the Trojan horses of AI. The goal of this study was to investigate the possibility to use an engineered NDV as a vector vaccine for influenza in ducks.
Example 4.1
Duck Study 1 in 14 Day-Old Muscovy Ducklings
The objective of the study was to compare (1) the immunogenicity and (2) the H5N1 efficacy induced by two AVINEW engineered mutants expressing the synthetic HA gene from 2 different H5N1 clades (vAVW02 is expressing the HA gene of clade 2.1 A/chicken/Indonesia/7/2003 and vAVW03 the HA from clade 2.2 A/turkey/Turkey/1/2005) with that of the parental Avinew strain in conventional Muscovy ducklings.
Example 4.1.1
Duck Study 1: Immunogenicity of Engineered Avinew Mutants in Ducklings
One-day-old Muscovy ducklings were tested for NDV and AIV serology and 7/10 ducklings were surprisingly found seropositive for NDV with a mean HI titre of 3.9 log 2. All sera were negative for the AI HI test. Another blood sampling taken at 13 day of age in 10 ducks gave negative ND HI titres and the study was started when ducks were 14 day of age. Three groups were set up, with ten vaccinated and seven contact control ducklings in each. Contacts were separated the days of vaccinations (D0 & D21) and were set back into the Group the following day. A fourth group of 5 unvaccinated controls was included (see Table 7).







TABLE 7







Duck study 1: Group setting for the evaluation of immunogenicity


of AVINEW mutants expressing HA.















Dose (50 μl




Vaccine

eye drop on


Group
Nb ducks
(D0&D21)
HA insert
D0 & D21)





1
10 vacc. + 7 contacts
AVINEW
—
10 chicken






doses


2
10 vacc. + 7 contacts
vAVW02
A/ck/
6.5 log10





Indonesia/
EID50





7/2003


3
10 vacc. + 7 contacts
vAVW03
A/tk/Turkey/
6.5 log10





1/2005
EID50


4
5
—
—
—









Blood sampling were taken at D0, D21 & D42 for NDV and AI HI test and AI SN test using the MDCK cell-adapted M6 11804 H5N1 HPAI Hungarian strains. Throat and cloacal swabs in vaccinated animals on D4, D7 & D12 and in contact animals on D7 & D12 were taken for NDV-specific real time PCR (primers M4100 & M4220 and probe M4169) (Wise et al. (2004) J. Clin Microbiol 42, 329-348).
The results showed that no adverse reaction was observed, indicating that the 3 vaccines were safe in these experimental conditions. All samples from group 4 (unvaccinated controls) were negative for PCR & serology. All samples from the unvaccinated contact birds in groups 1 to 3 were negative for PCR & serology indicating that the vaccine did not spread from the vaccinated birds to the contacts. NDV HI titres are shown in FIG. 19. At D21, HI titres of G1 (3.6 log 2; 100%≧3 log 2) were significantly higher (ANOVA; p=0.004) than those of G2 (100%<3 log 2) and G3 (3/10≧3 log 2). However, 3 weeks after the second administration, mean NDV HI titres were similar (ANOVA; p=0.682) in the 3 vaccinated groups (5.1, 5.7 and 6.1 log 2 in group 1, 2 and 3, respectively).
AI H5N1 HI titres are shown in FIG. 20. No detectable HI titres (<3 log 2) was observed at D21 after the first vaccination in ducks from G2 and G3 except 1 duck in G2 that had a 4 log 2 HI titre. After the second administration, HI titres of all ducks were ≧3 log 2 with a mean titre of approx. 4 log 2. There was no significant difference in the AI HI titre induced by the two AVINEW mutants vAVW02 & 03 at both times.
AI H5N1 seroneutralizing (SN) titres are shown in FIG. 21. No detectable SN titres (<2 log 2) was observed at D21 after the first vaccination in ducks from G2 and G3 except 2 ducks in G3 that had a 2 or 3 log 2 SN titre. After the second administration, HI titres of all ducks were ≧4 log 2 with a mean titre of approx. 6.2 log 2. There was no significant difference in the AI HI titre induced by the two AVINEW mutants vAVW02 & 03 at both times.
NDV PCR: Results of NDV PCR are shown in Table 8. Only a few ducks were found positive after the first and second vaccination in groups 1 and 3. All positive samples were from throat swabs except one swab in group 3 at D28. The 2 ducks positive at D25 after the 2nd administration of AVINEW were the only birds positive after the first administration at both D3 and D7. All samples were negative in group 2, despite induction of anti-ND and anti-AI antibodies.







TABLE 8







Duck study 1: Results of NDV real-time PCR testing in throat


and cloacal swabs (numbers of positive ducks/total)













Vaccine
After V1

After V2













Group
(D0&D21)
D4
D7
D25
D28





1
AVINEW
3/10
2/10
2/10
2/10


2
vAVW02b
0/10
0/10
0/10
0/10


3
vAVW03
7/10
2/10
2/10
 3/10*





*All positive samples were from throat swabs except 1 of the 3 positive birds in G3 at D28 whose cloacal swab was positive.






In summary, the study confirmed the safety of AVINEW and showed that insertion of the HA gene into the AVINEW-AI mutants did not induce adverse reactions in ducklings. AVINEW induced significantly higher NDV HI titres after the first administration than the 2 tested AVINEW-AI mutants, suggesting that insertion of the HA gene impairs slightly the NDV replication. Two eye drop administrations of 10 chicken doses of the AVW-AI mutants were needed to induce positive NDV and AI HI titres as well as AI SN titres in all ducks. There was no difference in the immunogenicity against a clade 2.2 H5N1 antigen of the two tested AVINEW-AI mutants despite the presence of HA gene from 2 different clades (clade 2.1 in vAVW02 and clade 2.2 in vAVW03). Only a few birds vaccinated with AVINEW and vAVW03 shed the virus mainly into throat swabs. However, this shedding was insufficient to transmit the vaccine virus to contact ducklings that remained negative during the whole study. Some ducks of this study were subsequently challenged with an H5N1 Hungarian isolate; the results of the challenge are presented in Example 4.1.2.
Example 4.1.2
Duck Study 1: H5N1 Protection Induced by Engineered Avinew Mutants in Muscovy Ducklings
A H5N1 challenge study was performed in a few ducks vaccinated with vAVW02 or vAVW03 (see Example 4.1.1). Four of the ducks vaccinated twice by eye drop with vAVW02 or 03 were challenged at 9 weeks of age. Two ducks of groups 1 (AVINEW) were used as negative controls. Mean H5 HI titres were 5.5 log 2 (4 ducks at 5 and 4 at 6 log 2) and mean SN titres were 4.0 log 2 (1 at 3, 6 at 4 and 1 at 5 log 2 SN titre) in the vAVW02 & 03 vaccinated groups. The 8 vaccinated and 2 control ducks were challenged by an IM administration of 4.7 log 10 EID50 of the HPAI H5N1 A/duck/Hungary/11804/2006 (M6 11804) strain. Cloacal and throat swabs were taken at days 2, 7 and 10 after challenge and heart, pancreas, brain and spleen were sampled at necropsy and tested by PCR and histopathology.
The results are summarized in Table 9. The 2 controls died within 48 hours post-infection. Oronasal and cloacal swabs as well as brain, pancreas, heart and spleen were positive for H5N1 by PCR. Histopathology of the different organs showed signs of a peracute H5N1 infection. No clinical signs were observed in the 8 vaccinated ducks during the 10 day observation period. Shedding was only detected in the throat swab of 3 of the 8 vaccinated ducks (2 in G2 and 1 in G3) at day 3 post-challenge. One of these positive ducks (the one in G3) was also positive for AI PCR in the cloacal swab. All other swabs and organs were negative. No lesion was found in the organs of vaccinated ducks.







TABLE 9







Duck study 1: Summary of the results of protection induced by AVINEW vector


vaccines in 14 day-old Muscovy ducklings.














Dose in

Clinical






log10
Vaccin.
Signs &
Shedding
Organs
Organs


Vaccine
EID50
Day
mortality
(PCR)
(PCR)
(lesions)





AVINEW
6.5
D0 + D21
2/2 (2 dpi)
2/2
2/2
2/2


vAVW02
6.5
D0 + D21
0/4
2/4 (throat)
0/4
0/4


vAVW03
6.5
D0 + D21
0/4
1/4 (throat + cloacal)
0/4
0/4









The result showed that the IM challenge was very severe in the 2 control birds. Full clinical and partial shedding protection was observed in the 8 ducks vaccinated twice by eye drop with an AVINEW vector vaccine expressing a synthetic H5 gene from H5N1 isolate.
Example 4.2
Duck Study 2 in One-Day-Old Muscovy Ducklings
The objective of the duck study in this example was to compare the immunogenicity (example 4.2.1) and the efficacy (example 4.2.2) induced by one or two administrations of the vAVW03 AVINEW mutant expressing the synthetic HA gene from clade 2.2 A/turkey/Turkey/1/2005 in day-old Muscovy ducklings.
Example 4.2.1
Duck Study 2: Immunogenicity Of Engineered Avinew Mutants in One-Day-Old Ducklings
The animals used in this study were one-day-old Muscovy ducklings that were all found negative for NDV (HI) and AIV (HI & SN) serology. Three groups were set up, with ten vaccinated and five contact control ducklings in each. Contacts were separated the days of vaccinations (D0 & D21) and were set back into the Group the following day. A third group of 5 unvaccinated controls was included (see Table 10). Ten vaccinated ducklings from group 1 and 2 were vaccinated by eye drop of 50 μl containing 6.5 log 10 EID50 vAVW03 at D0 (group 1 and 2) and at D14 (group 2, only).







TABLE 10







Duck study 2: Group setting for the evaluation of immunogenicity of


1 or 2 administrations of the AVINEW mutant vAVW03 expressing HA.










Group
Nb ducks
Vaccine
Vacc. Time





1
10 vacc. + 5 contacts
vAVW03
D0


2
10 vacc. + 7 contacts
vAVW03
D0 + D14


3
5
—
—









Blood sampling were taken at D0, D14 & D35 and tested for NDV (La Sota antigen) and AI (M6 11804 HPAI H5N1 Hungarian/2006 antigen) antibodies with the HI test and for AI by SN test using the MDCK cell-adapted M6 11804 H5N1 HPAI Hungarian strains.
No adverse reaction was observed, confirming the safety of vAVW03 for day-old Muscovy ducklings. NDV HI titres and AI SN titres are presented in FIGS. 22 A and B, respectively. At d14, 2 weeks after the first administration of vAVW03, only 10/20 vaccinated ducks had detectable NDV HI titres (≧3 log 2) and only 8/20 had detectable H5N1 SN titres (≧1 log 2). At d35, HI and SN titres remained similarly low in group 1 (6/10 positive with NDV HI test (mean of 2.9 log 2) and 8/10 positive with SN H5N1 test (mean of 1.3 log 2) and increased in group 2 after the 2nd administration of vAVW03. All samples from the control group (group 3) were negative for both NDV HI test and H5N1 SN test. All serums from unvaccinated contact ducks in groups 1 and 2 were also negative for NDV H1 and H5N1 SN except one duck in group 2 that seroconvert to NDV (3 log 2) and to SN H5N1 (1 log 2). This suggests that the vAVW03 vaccine spread in group 2 from vaccinated to 1 out of the 5 unvaccinated contacts. Some ducks of this study were subsequently challenged with an H5N1 Hungarian isolate; the results of the challenge are presented in Example 4.2.2.
The results showed that the safety of vAVW03 was confirmed in one-day-old ducklings. One eye-drop administration of 6.5 log 10 EID50 of vAVW03 in one-day-old Muscovy ducklings induced detectable low NDV HI titers and H5N1 SN titers in 40-50% birds only. A clear boost effect in NDV and SN H5N1 titers was observed after a second eye drop administration of vAVW03. The detection of low anti-NDV and anti-H5N1 antibody in one unvaccinated duck placed in contact with ducks of group 2 vaccinated twice at D0 and D14 suggests that, in contrast to the previous study, horizontal transmission could happen at a low frequency in the tested conditions.
Example 4.2.2
Duck Study 2: AI H5N1 Efficacy of Engineered AVINEW-AI Mutants in One-Day-Old Ducklings
A H5N1 challenge study was performed in a few ducks vaccinated once or twice with the vAVW03 AVINEW-AI mutant expressing the HA gene of a clade 2.2 (see Example 4.2.1).
Five ducks from groups 1 (1 administration at D0) and 2 (2 administrations at D0 and D14) as well as two unvaccinated ducks in contact with birds of groups 1 and 2 and two unvaccinated ducks from group 3 were challenged at 5 weeks of age. The 10 vaccinated, the 4 contact and the 2 control ducks were challenged by an oronasal administration of 4.7 log 10 EID50 of the HPAI H5N1 A/duck/Hungary/11804/2006 (M6 11804) strain. Cloacal and throat swabs were taken at day 4 and day 7 and at day of death. Ten days after the challenge or at time of death, heart, pancreas, brain, liver and spleen were sampled at necropsy and tested by PCR and histopathology.
Individual results are shown in table 11. The 2 controls from group 2 died within 48 hours post-infection. Oronasal and cloacal swabs as well as brain, pancreas, heart and spleen were positive for H5N1 by PCR. Histopathology of the different organs showed signs of a peracute H5N1 infection. No clinical signs were observed in the 10 vaccinated ducks of groups 1 and 2 during the 10 day observation period. One duck in group 1 (#402) did not have detectable NDV and H5N1 antibodies and another duck (#403) had a low NDV HI titre only. This result indicated that these antibody tests may not be fully predictive in terms of clinical protection. Shedding was detected in three of the five ducks of group 1 (2 in both swabs and 1 in throat swab only) and only one duck of group 2 (throat swab only) at D4. At D7, only one duck of group 1 and group 2 were positive for shedding in the throat swab. All other swabs and organs were negative. No lesion was found in the organs of vaccinated ducks. All unvaccinated ducks that were kept in contact with vaccinated birds of group 1 and group 2 died within 2 or 3 days, and were positive by PCR analysis in their swabs and organs as the control ducks from group 3, except one contact duck (#429) from group 2 that was fully protected. Interestingly, it was the only contact duck that showed low levels of NDV and H5N1 antibodies at the time of challenge suggesting that the vaccine has been transmitted from the vaccinated ducks to this contact ducks. This duck did not show any clinical signs and was negative by PCR in its swabs and organs. Study of histopathologic lesions in different organs of the ducks that died after challenge was performed, which included: brain (incipient lymphocytic encephalitis), liver (acute, serous hepatitis with multiplex focal necrosisof the parenchyma), heart (interstitial oedema, petechae in the myocardium), pancreas (hypeaemia, interstitial oedem), small intestine (hyperaemia, oedema in the mucus membrane), spleen (hyperaemia, lymphocyte depletion in the Malpighi bodies), lung (hyperaemia, interstitial oedema, incipient focal interstitial pneumponia), Trachea (oedema in the mucus membrane). The result showed mild histopathologic changes including encephalitis, oedema, hyperaemia and necrosis of hepatocytes in different organs.







TABLE 11







Duck study 2: Individual results of protection in the duck study 2 performed with


vAVW03 given once (D0) or twice (D0 and D14) in day-old Muscovy ducklings.














NDV HI
AI SN
Clinical
Shedding





titre
titre
signs &
(PCR)*
Organs
Organs
















Group
Bird
(log2)
(log2)
mortality
D2/3
D4
D7
(PCR)
(lesions)



















1
401
4
2
−
nd
−
−
−
−


vAVW03 at
402
<3
<1
−
nd
T
T
−
−


D0
403
3
<1
−
nd
T, C
−
−
−



405
4
1
−
nd
−
−
−
−



408
3
2
−
nd
T, C
−
−
−


2
412
5
3
−
nd
−
−
−
−


vAVW03 at
413
5
3
−
nd
T
T
−
−


D0 + D14
417
5
2
−
nd
−
−
−
−



419
5
4
−
nd
−
−
−
−



420
3
2
−
nd
−
−
−
−


1
421
<3
<1
+ (D2)
T, C


+
+


Unvacc.
424
<3
<1
+ (D3)
T, C


+
+


Contacts


2
426
<3
<1
+ (D2)
T, C


+
+


Unvacc.
429
3
1
−
nd
−
−
−
−


Contacts


3

<3
<1
+ (D2)
T, C


+
+


Unvacc.

<3
<1
+ (D2)
T, C


+
+





*T = positive throat swab; C = positive cloacal swab






The result showed that the oronasal challenge was very severe despite the relatively low dose used (4.7 log 10 EID50), suggesting that this Hungarian H5N1 isolate (isolated from ducks) has a high level of virulence for Muscovy ducks. Full clinical protection was observed in all vaccinated ducks, even those that received only 1 administration of vAVW03 at day-old, 5 weeks before the challenge and that did have a low or undetectable NDV H1 or H5N1 SN titre. Shedding was observed in a lower number of ducks in group 2 (1/5) that received 2 vaccine administrations compared to group 1 (3/5) that received only one administration. Interestingly, the only contact duck that had detectable NDV and H5N1 antibody titers before challenge likely due to the horizontal transmission of the vAVW03 vaccine from the vaccinated ducks was fully protected.
Example 4.3
Duck Study 3 in One-Day-Old Muscovy Ducklings
The objective of the duck study in this example was to confirm H5N1 protection induced by vAVW03 alone or associated with other vaccines against another H5N1 HPAI isolate in one-day-old SPF Muscovy ducklings.
The study design is shown in Table 12. The immunogenicity of a single vAVW03 administration was compared with that of 2 administrations of vAVW03 and a heterologous prime-boost scheme consisting of priming at D0 with the TROVAC-AIV H5 vector vaccine (fowlpox recombinant vFP89 expressing the native HA gene of the HPAI H5N8 A/turkey/Ireland/1378/1983 isolate; licensed in USA) using 10 chicken doses (about 4.5 log 10 TCID50/dose) by the subcutaneous route followed by vAVW03 at D14 administered by the mucosal route (see details in Table 12). At D28 and D42, 5 ducks of each group were challenged with the French HPAI H5N1 clade 2.2 A/swan/France/06299/06 isolate (106 EID50/duck).







TABLE 12







Duck study 3 design and results of protection













Protected/total




Vaccine* (dose)**
(MTD) after



Num-
administered at
H5N1 challenge*** at












Group
ber
D0
D14
D28
D42





1
5 + 5
—
—
0/5 (3.4)
0/5 (3.4)


2
5 + 5
vAVW03 (5.5)
—
5/5
5/5


3
5 + 5
vAVW03 (5.5)
vAVW03 (5.5)
5/5
5/5


4
5 + 5
TROVAC-AIV
vAVW03 (5.5)
5/5
5/5




H5 (4.5)





*vAVW03 was administered by the oculo-nasal route with 50 μl vaccine suspension (mineral water used as diluent); TROVAC-AIV H5 was administered by the subcutaneous route with 0.2 ml vaccine suspension (Marek's vaccine diluent used as diluent).


**dose of vAVW03 is expressed in log10 EID50 and of TROVAC-AIV H5 as log10 TCID50; the dose of TROVAC-AIV H5 corresponds to 10 chicken doses of a commercial batch of this vaccine


***The challenge strain was the HPAI H5N1 clade 2.2 A/swan/France/06299/06 isolate; 6 log10 EID50 administered by oculonasal route; MTD: mean time to death in days






All non-vaccinated ducks showed clinical signs and died within 4 days after challenge. None of the vaccinated ducks showed clinical signs or died (see Table 12). Oropharyngeal and cloacal swabs were sampled at different times after challenge (2.5, 4.5, 6.5, 9.5, and 11.5 day post-challenge). Viral load was measured by the M-based real-time RTPCR based on Spackman et al (2002) J Clin Microbiol 40:3256-3260. Results of challenge at D28 and D42 are presented at FIGS. 23a-d and 24a-d, respectively.
The shedding data clearly indicated that the vaccinated ducks shed fewer viruses than the non-vaccinated controls and the percentage of positive birds was also reduced after both challenges at D28 (FIGS. 23a-d) and D42 (FIGS. 24a-d). There was no difference between samples from group 2 and 3, indicating that one vAVW03 administration at one day of age provided the same protection as two vAVW03 immunizations at D0 and D14 in these conditions. Percentages of positive as well as virus loads were lower in ducks from group 4 that received the heterologous prime-boost regimen compared to those of groups 2 and 3, especially for the challenge at D28. These results indicate that a priming with a fowlpox recombinant expressing another HA gene from the same subtype administered before vAVW03 improves the level of protection compared to 1 or 2 administrations of vAVW03.
The AI HI titers were measured in serums sampled before (D28 and D40) and after (D42 and D57) challenge at D28 and D42, respectively, using an HPAI H5N1 (French isolate 06167i H5N1 clade 2.2.1 close to the challenge strain) as the antigen (See Table 13). Only a few ducks of group 4 had detectable HI titers at D28. It is interesting to note that despite the absence of detectable seroconversion against AI at the time of challenge, all vaccinated ducks were protected against the severe HPAI challenge. This result confirms previous one indicating that HI test cannot be used to predict the efficacy of such engineered NDV AI vaccine.
Fourteen day after challenge at D28, HPAI H5N1 HI titers increased from 0 at D28 to 7.2 log 2 at D42 in groups 2 and 3 whereas in group 4, they increased from 2.3 (D28) to 6.0 (D42). The lower increase of HI titers after challenge in group 4 compared to groups 2 and 3 suggested that the challenge virus replicated less in this group. Such decrease of challenge virus replication in ducks of group 4 was observed in the shedding data after challenge at D28 (see above and FIGS. 23a-d).







TABLE 13







Duck study 3. Mean AI HI titers (log2) before and after challenge










Challenge at D28
Challenge at D42











Group
D28 (prech.)
D42 (postch.)
D40 (prech.)
D57 (postch.)





1
0 (0/7)
—
  0 (0/7)
—


2
0 (0/7)
7.2 (5/5)
0.4 (0/7)
8.6 (5/5)


3
0 (0/5)
7.2 (5/5)
  0 (0/7)
8.4 (5/5)


4
2.3 (2/6)  
6.0 (4/4)
0.9 (0/7)
8.2 (5/5)









In summary, one (D0) or two (D0 and D14) mucosal deliveries of vAVW03 administered to one-day-old Muscovy ducklings protected them against HPAI H5N1 challenges performed at D28 and D42. A heterologous priming with a fowlpox recombinant expressing an HA from an H5N8 isolate before vAVW03 administration improved the protection against an early challenge at D28.
Example 4.4
Duck Study 4—Duration of Immunity in One-Day-Old Muscovy Ducklings
The objective of the Duck Study in this example was to evaluate the duration of immunity induced by one administration of vAVW03 or that induced by the heterologous TROVAC-AIV H5/vAVW03 prime-boost scheme tested in Duck study 3.







TABLE 14







Duck study 4 design and results of clinical protection












Vaccine2 (dose)3
Protected4/total (MTD)



Num-
administered at
after H5N1 challenge5 at












Group
ber1
D2
D15
D65
D86





1
5 + 5
—
—
0-0/5 (4.1)
0-1/5 (5.4)


2
8 + 9
vAVW03 (5.5)
—
7-8/8
8-8/9 (9.5)


3
8 + 8
TROVAC-
vAVW03
7-8/8
8-8/8




AIV H5 (4.5)
(5.5)


4
8 + 8
—
Inactivated
Not done
8-8/8





1Number of ducks for the challenge at D65 + at D86 (Mean Time to Death in days)


2vAVW03 was administered by the oculo-nasal route with 50 μl vaccine suspension (mineral water used as diluent); TROVAC-AIV H5 was administered by the subcutaneous route with 0.2 ml vaccine suspension; inactivated vaccine is a commercial oil-adjuvanted inactivated vaccine vaccine that contains Re5 reverse genetics H5N1 isolate including the HA (modified at the cleavage site) and NA genes from the clade 2.3 A/duck/Anhui/1/2006 isolate.


3Dose of vAVW03 is expressed in log10 EID50 and of TROVAC-AIV H5 as log10 TCID50; the dose of TROVAC-AIV H5 corresponds to 10 chicken doses of a commercial batch of this vaccine.


4Number of birds protected against morbidity − number of birds protected against mortality/total (MTD: mean time to death in days).


5The challenge strain was the HPAI H5N1 clade 2.2 A/swan/France/06299/06 isolate; 6 log10 EID50 administered by oculonasal route.






None of the birds developed detectable AI HI antibodies against the HP H5N1 06167i clade 2.2.1 antigen (close to the challenge strain) before challenge.
These late challenges were effective since they induced 100% morbidity and killed most of the unvaccinated control ducks (only one sick bird survived the late challenge at D86; see Table 14). Most birds vaccinated with vAVW03 were protected; only 1/8 showed mild clinical signs and survived at the D65 challenge and 1/9 showed clinical signs and died at the D86 challenge. All birds from the prime-boost (TROVAC AIV-H5 at D2 and vAVW03 at D15) group survived both challenges; only one bird showed clinical signs at the earlier (D65) challenge. None of the birds from group 4 vaccinated with the inactivated Re5 vaccine showed clinical signs or died.
The oropharyngeal and cloacal shedding was also investigated after challenge. All control birds shed viruses at high levels (6.8 and 4.9 equivalent EID50/mL by the oropharyngeal and cloacal routes, respectively) and for at least 9.5 days (for the survivor). In group 2 and 3, the level of shedding was lower (about 1 and 2 log 10 lower, respectively) and it decreased faster than the control group. Shedding profiles in group 4 were close to those observed in group 3.
In conclusion, one administration of vAVW03 to Muscovy ducklings (2 days of age) provided a good level of protective immunity up to 84 days of age. The prime-boost regimen with a fowlpox vector followed by a NDV vector provides a better protective immune response than one administration of the NDV vector and a similar protective response as the inactivated Re5 vaccine.
Example 4.5
Duck Study 5—vAVW003 Efficacy in Pekin Ducklings
The objective of this study was to evaluate the efficacy of vAVW03 in Pekin ducks against an HPAI H5N1 challenge. Seven-day-old Pekin ducklings were vaccinated as shown in Table 15. The challenge strain was the HPAI H5N1 clade 2.2 A/turkey/Turkey/1/2005 isolate; 6 and 7 log 10 EID50 administered by oculonasal route were used at D28 and D42, respectively. Clinical signs (morbidity) and deaths (mortality) were recorded after challenge. Shedding was measured after challenge using a real time RT-PCR in buccal and cloacal swabs taken 2, 5, and 8 days post-challenge (dpc). The study design and results of protection are shown in Table 15.







TABLE 15







Duck study 5 design and results of protection











Vaccine1 (dose)2





administered at
Results of challenge at D28
Results of challenge at D42
















Gp
Number
D0
D14
Morbidity
Mortality
Detection5
Morbidity
Mortality
Detection





1
10
—
—
6/10
5/10
10/10 
3/10
6/10
9/10


2
10
—
Re54
0/9 
0/9 
5/9 
0/10
0/10
1/10


3
10
vAVW03
—
0/10
0/10
0/10
0/10
0/10
5/10




(5.5)


4
10
vAVW03
vAVW03
0/10
0/10
0/10
0/10
0/10
2/10




(4.5)
(5.5)


5
10
vFP893
vAVW03
0/10
0/10
0/10
0/9 
0/9 
4/9 




(4.5)
(5.5)





1vAVW03 was administered by the oculo-nasal route with 50 μl vaccine suspension (mineral water used as diluent); TROVAC-AIV H5 was administered by the subcutaneous route with 0.2 ml vaccine suspension (Marek's vaccine diluent used as diluent).


2dose of vAVW03 is expressed in log10 EID50 and of TROVAC-AIV H5 as log10 TCID50; the dose of TROVAC-AIV H5 corresponds to 10 chicken doses of a commercial batch of this vaccine


3vFP89: fowlpox vector AIV H5 (see, US 2008/0107681 and US 2008/0107687).


4Re5: Oil-adjuvanted inactivated vaccine based on a reverse genetics strain containing the modified HA gene and NA gene from the HPAI H5N1 A/duck/Anhui/1/2006 (clade 2.3).


5Number of chickens positive for buccal or cloacal swabs at 2, 5 or 8 dpc.






The results indicated that Pekin ducks are relatively resistant to the H5N1 challenge since only about half of the non-vaccinated birds showed clinical signs or died after challenge. Nevertheless, most of them shed detectable amount of virus indicating active replication of the challenge strain. All vaccinated ducks were clinically protected at both challenge dates and the number of birds shedding virus was reduced compared to the unvaccinated controls. These results indicate that significant protection can be induced by vAVW03 in Pekin ducklings.
Example 4.6
Duck Study 6—vAVW003 Efficacy in One-Day-Old Pekin Ducklings with NDV MDAs
The objective of the Duck Study 6 was to evaluate the HPAI H5N1 efficacy induced by one administration of vAVW03 in Pekin ducks born from breeders vaccinated with an inactivated combo vaccine containing NDV antigen in order to evaluate the effect of NDV MDAs on the vAVW03-induced efficacy. Two-day-old Pekin ducklings with NDV MDAs were used in this study. SPF Muscovy ducklings were also used to validate the challenge. The study design and protection data is presented in Table 16.







TABLE 16







Duck study 6 design and results of protection against HPAI H5N1 challenge










Vaccination
Protection** against













Ducks
at D0
Morbidity
Mortality
%















Group
Species
Number
Vaccine
dose
Route*
(MTC)
(MTD)
protection


















1
Muscovy
7
—

—
0/5
0/5 (3.5)
0%


2
Pekin
7
—

—
2/5 (4.2)
4/5 (6.5)
40%


3
Pekin
14
vAVW03
5.5
ON
8/9 (11.5)
9/9
89%


4
Pekin
11
vAVW03
6.5
ON
6/9 (6.8)
6/9 (7.2)
67%


5
Pekin
11
vAVW03
5.5
Oral
7/9 (8.5)
8/9 (6.5)
78%


6
Pekin
11
vAVW03
6.5
Oral
8/9 (6.5)
8/9 (6.5)
89%





*ON = oculo-nasal


**The challenge strain was the HPAI H5N1 clade 2.2 A/swan/France/06299/06 isolate; 6 log10 EID50 administered by oculonasal route at D24; MTC: mean time to clinical signs in days; MTD: mean time to death in days






The HPAI H5N1 challenge was validated by the rapid mortality (all died 3.5 days post-challenge) of the non-vaccinated Muscovy ducklings used as controls. However, the non-vaccinated Pekin ducks were much more resistant to the H5N1 challenge since only 3/5 showed clinical signs and only 1/5 died 6.5 days post-challenge. Partial protection (from 67 to 89%) against morbidity was induced by vAVW03 and there was no clear dose- or administration route-effect in Pekin ducklings.
All control Pekin ducks shed virus by the oropharyngeal route. The shedding was decreased in load, time and number of positive birds in the vaccinated groups.
This study shows that AI protection can be induced with one administration of vAVW03 in Pekin ducks with NDV MDAs.
Having thus described in detail preferred embodiments of the present invention, it is to be understood that the invention defined by the above paragraphs is not to be limited to particular details set forth in the above description as many apparent variations thereof are possible without departing from the spirit or scope of the present invention.
All documents cited or referenced in the application cited documents, and all documents cited or referenced herein (“herein cited documents”), and all documents cited or referenced in herein cited documents, together with any manufacturer's instructions, descriptions, product specifications, and product sheets for any products mentioned herein or in any document incorporated by reference herein, are hereby incorporated herein by reference, and may be employed in the practice of the invention.

## Claims

1. A method for modifying the genome of Newcastle Disease Virus (NDV) to produce engineered NDV vector, wherein the method comprises the introduction into the NDV genome an isolated heterologous polynucleotide in a non-essential region of the NDV genome, and wherein the NDV comprises a genome having at least 95% sequence identity to a polynucleotide having the sequence as set forth in SEQ ID NO:1 or a genome complementary to a polynucleotide having at least 95% sequence identity to the polynucleotide having the sequence as set forth in SEQ ID NO:1.

2. The method of claim 1, wherein the non-essential region is selected from the regions consisting of untranslated regions located upstream the NP gene, between two genes of the NDV genome, and downstream of the L gene.

3. The method of claim 2, wherein the non-essential region is located between the P and M genes or between the M and F genes.