DEVELOPMENT OF AN EFFECTIVE VACCINE AGAINST FOOT-AND-MOUTH-DISEASE WITH PARTIALLY PURIFIED AND CONCENTRATED VIRUS-ANTIGEN

Foot-and-mouth disease (FMD) virus is poorly immunogenic. There is nee d to improve the quality of the vaccine by incorporating enhanced quan tity of purified virus antigen to prevent sporadic breakdown of immuni ty in regularly vaccinated organized herds. A technique has been stand ardized for virus purification and concentration by polyethylene glyco l (PEG) treatment for large scale production of concentrated FMD vacci ne. The vaccine prepared with tenfold concentrated antigen was given f ield trial in an organised farm with a reduced dose as compared to the conventional vaccine. High level serum neutralizing antibody in cattl e was observed throughout the entire period of study. The concentrated vaccine controlled the spread of the disease when used in face of out break in villages adjacent to the organized farm.