Initial Study of Malaria Vaccine Pfs25-EPA/Alhydrogel(Registered Trademark)
Condition: Malaria
MeSH terms: Malaria
Study type: Interventional
Phase: Phase 1

Summary: 
      Background:

      - The malaria vaccine Pfs25-EPA/Alhydrogel may help block malaria parasites from developing
      in mosquitoes. When a mosquito bites a vaccinated person, the vaccine should prevent
      parasites from developing in the mosquito. As a result, the mosquito will not spread malaria
      to the next person it bites. However, the vaccine will not directly prevent people from
      getting sick with malaria. Researchers want to test the safety of and response to this
      vaccine.

      Objectives:

      - To test the safety of the malaria vaccine Pfs25-EPA/Alhydrogel.

      Eligibility:

      - Healthy volunteers between 18 and 50 years of age.

      Design:

        -  Participants will be screened with a medical history, physical exam, and blood tests.

        -  They will be assigned to a study group to have either two or three doses of the vaccine.
           Participants will have checkups after each dose of vaccine,

        -  The additional doses will be given 2 months or 2 and 4 months after the first vaccine.

        -  Participants will have regular blood tests to check the level of the response to the
           vaccine.

        -  They will be followed for up to 1 year after the last vaccine to have any additional
           tests as needed.
    

Detailed description: 
      A vaccine to interrupt malaria transmission would be a valuable tool for local elimination or
      eradication of this disease. Pfs25, a surface antigen of ookinetes in the mosquito stage of
      P. falciparum, is a lead candidate for a malaria transmission blocking vaccine. Recombinant
      Pfs25 has been conjugated to Pseudomonas aeruginosa ExoProtein A (EPA), and adjuvanted with
      Alhydrogel(Registered Trademark). This open label, dose escalating Phase 1 study in malaria
      naive adults, conducted at Johns Hopkins Bloomberg School of Public Health Center for
      Immunization Research (CIR) in Baltimore, Maryland, will determine initial safety and
      immunogenicity of the vaccine given on a 2-dose,3-dose, or 4-dose schedule. Thirty (30)
      volunteers will be enrolled, with 5 receiving the low dose (8 micro g of conjugated Pfs25), 5
      receiving the middle dose (16 micro g of conjugated Pfs25), and 20 receiving the high dose
      (47 micro g of conjugated Pfs25). The high dose group will receive either 2, 3 or 4 doses of
      vaccine, on a 0, 2, 4 and 10 month vaccination schedule. Volunteers will be followed for 12
      months following the last vaccination. Safety outcomes will be local and systemic adverse
      events (AEs). Immunogenicity outcomes will be antibody responses as measured by ELISA,
      transmission blocking in a standard membrane feeding assay, and B and T cell responses.
    

Intervention name(s): Pfs25-EPA/Alhydrogel
Intervention type(s): Biological
Intervention MeSH terms: Aluminum Hydroxide
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Recombinant; Proteins; Antigen; Membrane; Assay; Malaria