Preparation of inactivated poliomyelitis vaccine with attenuated sabin strains.

Inactivated poliomyelitis vaccines were prepared with each type of concentrated and purified attenuated and virulent viruses (Sabin 1, 2, 3, Mahoney, Brunhilde, MEF-1 and Saukett). During inactivation period with formalin, no significant difference were observed for the decrease of virus infectivity between Sabin and virulent viruses. By analysis of D antigen content with gel diffusion test befor and during inactivation period, type 1 Mahoney showed instability and could be recovered only 29% of D antigen at the end of inactivation period, but Sabin type 1 showed good stability as well as other types of Sabin and virulent viruses.In immunization tests with guinea pigs, inactivated Sabin viruses induced good seroconversion against not only homologous Sabin virus but also virulent virus.These results indicate that it seems possible to make inactivated poliomyelitis vaccine with Sabin viruses having comparable immunogenicity to the vaccine from virulent viruses. By use of attenuated virus the safety of the vaccine is improved and the vaccine can be prepared in the facilities in which live oral vaccine is producing.