STABILIZED LIVE ATTENUATED VACCINE AND ITS PRODUCTION

Abstract: A vaccine, which comprises at least one live attenuated plain virus selected from measles, mumps or rubella virus and, as a stabilizing agent, 2.5 to 5 W/V% lactose, 2.5 to 5 W/V% saccharose, 1.8 to 2 W/V% D-sorbitol, about 0.1 W/V% sodium glutamate and 2 to 3 W/V% gelatin hydrolysate having a molecular weight of about 35,000.

Description: This invention relates to a stabilized live attenuated vaccine and its production. A titer of live attenuated vaccine is in general temperature unstable. A vaccine preparation is therefore supplied as a low-temperature freezed product or a lyophilized product. To stabilize the vaccine further a chemical stabilizing agent may be added to the vaccine solution. Examples of chemical stabilizing agents are human albumin, gelatin hydrolyzate, sugar alcohols, amino acids and other non-toxic substances. Known examples are a preparation consisting of 5 W/V% of a basic amino acid such as arginine, lysine or histidine, or 5 W/V% of a sugar alcohol such as saccharose, adnitol or sorbitol (Japan. Patent Appln. No. 45-1887); a preparation comprising a mixture of 5 to 10 W/V% peptone, 3 W/V% arginine or lysine and 5 W/V% saccharose (Japan. Pat. Unexam. Publ. No. 50-2225), a preparation comprising 4 W/V% lactose and 2 W/V% sorbitol or 0.005M to 0.05M of at least one amino acid in a phosphate-buffer solution containing Ca⁺⁺ and Mg⁺⁺ (Japan. Pat. Appln. No. 57-81338), a preparation consisting of 5 W/V% lactose, 1.5 W/V% D-sorbitol, 0.3 W/V% dextran 70, 0.048% potassium glutamate, 0.0625 W/V% disodium phosphate, 0.026 W/V% potassium phosphate, 0.3 W/V% gelatin and 0.25 W/V% human albumin (Japan. Pat. Appln. No. 55-80465), and a preparation comprising a vaccine solution which has been acidified to pH 6.0 to 6.5 prior to lyophilization by adding a phosphate buffer solution containing a stabilizing agent comprising gelatin partial hydrolysate M.W. approx. 3,000, sorbitol, saccharose, lactose, maltose, L-glutamate and L-arginine (Japan. Pat. Unexam. Publ. No. 57-114527). EP-A-0 028 563 discloses a vaccine stabilizing composition in buffered solution containing gelatin, a monosaccharide (e.g. sorbitol, lactose) or disaccharide, glutamic acid (sodium salt) and arginine. Nowadays, vaccines have to be distributed to tropical countries where there are no cold-chain distribution systems. In these areas, the vaccine preparations which are supplied must have heat stability in high temperatures. The above stabilizing agents are not suitable for use in such conditions. We have found that a live attenuated vaccine shows strong thermostability when lactose, D-sorbitol, saccharose, gelatin hydrolysate and sodium glutamate at specific ratio in concentration were added to a vaccine virus suspension comprising medium-199 for cell culture (Morgan et al. Proc. Soc. Exp. Biol. Med.,73: 1-8, 1950) (hereinafter referred to as medium - 199). Each component is known as a stabilizing agent for a live attenuated vaccine, however it has not previously been known that a combination thereof at a specific concentration ratio exhibits unexpected thermostability. The present invention provides a vaccine, which comprises at least one live attenuated plain vaccine selected from measles, mumps or rubella virus, for example which has been grown in a medium-199 for cell culture, and, as a stabilizing agent, 2.5 to 5 W/V% lactose, 2.5 to 5 W/V% saccharose, 1.8 to 2 W/V% D-sorbitol, about 0.1 W/V% sodium glutamate and 2 to 3 W/V% gelatin hydrolysate having a molecular weight of about 35,000. The present invention also provides a process for preparing a vaccine which comprises adding at least one live attenuated plain vaccine selected from measles, mumps or rubella virus, lactose, saccharose, D-sorbitol, sodium glutamate and gelatin hydrolysate having a molecular weight of about 35,000, each being added individually or in any combination thereof, as a stabilizing agent, to provide a final concentration of 2.5 to 5 W/V% lactose, 2.5 to 5 W/V% saccharose, 1.8 to 2 W/V% D-sorbitol, about 0.1 W/V% sodium glutamate and 2 to 3 W/V% said gelatin hydrolysate. The stabilizing agent may be added directly to the virus in the medium in which the virus is cultured. The virus may be cultured in medium 199. The stabilizing agent may be dissolved in medium 199 at the desired concentration and aseptically filtered. The vaccine may be lyophilized and then reconstituted. In the present invention it is not required to adjust the pH of the vaccine solution to less than neutral but only to add each sterilized component. A further advantage of the present invention is that the vaccine does not contain human albumin which provides a superior stabilization effect; the additives used are more safe. Therefore the adverse effects of immunological preparations caused by the carrier or vehicle can be reduced. The thermostability of the vaccine of the present invention can be observed at virus suspension (Table 1), and is more apparent in the lyophilized product (Table 2). The thermostability of the lyophilized live attenuated vaccine product of the present invention is superior than that of the known vaccine preparation containing a conventional stabilizing agent. For example when a measles vaccine preparation containing a conventional stabilizing agent consisting of 5 W/V% lactose, 0.1 W/V% sodium glutamate and 0.2 W/V% gelatin hydrolysate is kept at 37° for one week, its titer decreases to 1/100 to 1/500 with loss of immunogenicity. In contrast the vaccine of the present invention loses its titer at most up to 1/3 without losing immunogenicity as compared with a titer of an original vaccine preparation. As shown in Figs. 1 and 2, the thermostability of mumps and rubella vaccines of the present invention is also superior than the commercial vaccine preparation containing a conventional stabilizing agent. A live attenuated measles vaccine of the present invention can be used for the worldwide project for prophylaxis of measles promoted by WHO, including in countries having no cold-chain distribution systems. Figs. 1 and 2 show the heat-stability of vaccines of the present invention and of commercially available vaccines. The following Example further illustrates the present invention. EXAMPLE 5 W/V% Lactose, 5 W/V% saccharose, 1.8 W/V% D-sorbitol, 0.1 W/V% sodium glutamate, and 2 W/V% gelatin hydrolysate having a molecular weight of about 35,000 [Behringwerke AG, West Germany, gelatin hydrolysate powder dissolved in medium-199 for raw material of "HEMACEL" (Trade name, gelatin hydrolysate for liquid transfusion)] were added to a measles vaccine virus suspension in medium-199 to prepare a bulk vaccine (2 batches). The bulk vaccine was lyophilized and finally 5 lots of vaccine preparation were produced. A comparative accelerated heat-stability test with this vaccine and a commercial vaccine lyophilized product (4 lots) was performed. Live attenuated mumps or rubella vaccines of the present invention were prepared, each in 2 batches, and the vaccine solutions were lyophilized to prepare 4 lots of each product. A comparative accelerated heat-stability test with commercial vaccine lyophilized products (each 2 lots) was carried out. As shown in Table 2 and Figs. 1 and 2, the decrease in titer of the lyophilized live attenuated measles, mumps and rubella vaccines of the present invention, after keeping at 37°C and at 45°C for one week, is significantly less than that of the commercially available conventional vaccines.

Claims: Claims for the following Contracting States : AT, CH, DE, FR, GB, IT, LI, LU, NL, SE A vaccine, which comprises at least one live attenuated plain virus selected from measles, mumps or rubella virus and, as a stabilizing agent, 2.5 to 5 W/V% lactose, 2.5 to 5 W/V% saccharose, 1.8 to 2 W/V% D-sorbitol, about 0.1 W/V% sodium glutamate and 2 to 3 W/V% gelatin hydrolysate having a molecular weight of about 35,000. A process for preparing a vaccine, which comprises adding to at least one live attenuated plain virus selected from measles, mumps or rubella virus, lactose, saccharose, D-sorbitol, sodium glutamate and gelatin hydrolysate having a molecular weight of about 35,000, each being added individually or in any combination thereof, as a stabilizing agent, to provide a final concentration of 2.5 to 5 W/V% lactose, 2.5 to 5 W/V% saccharose, 1.8 to 2 W/V% D-sorbitol, about 0.1 W/V% sodium glutamate and 2 to 3 W/V% said gelatin hydrolysate. A process according to claim 2 wherein the stabilizing agent is added directly to the virus in the medium in which the virus is cultured. A process according to claim 2 or 3 wherein the virus has been cultured in medium-199. A process according to claim 2, 3 or 4 which further comprises lyophilizing said vaccine. A process according to claim 5 which further comprises reconstituting the lyophilized vaccine. Claims for the following Contracting States : ES, GR A process for preparing a vaccine, which comprises adding to at least one live attenuated plain virus selected from measles, mumps or rubella virus, lactose, saccharose, D-sorbitol, sodium glutamate and gelatin hydrolysate having a molecular weight of about 35,000, each being added individually or in any combination thereof, as a stabilizing agent, to provide a final concentration of 2.5 to 5 W/V% lactose, 2.5 to 5 W/V% saccharose, 1.8 to 2 W/V% D-sorbitol, about 0.1 W/V% sodium glutamate and 2 to 3 W/V% said gelatin hydrolysate. A process according to claim 1 wherein the stabilizing agent is added directly to the virus in the medium in which the virus is cultured. A process according to claim 1 or 2 wherein the virus has been cultured in medium-199. A process according to claim 1, 2 or 3 which further comprises lyophilizing said vaccine. A process according to claim 4 which further comprises reconstituting the lyophilized vaccine.

Inventors: MAKINO, SATOSHI, NAKAGAWA, MASAHARU, SASAKI,KEIKO
Applicants: THE KITASATO INSTITUTE
Application year: 1988
Main classification: A61K39
IPC codes: A61K39