We devised the vaccination with formalin inactivated virus of Japanese encephalitis mixed with complete adjuvant to the swine, rabbits and chicks for inducing high titer of hemoagglutinin inhibiting (HI in short) and neutralizing antibody which could prevent viremia, when these animals were bitten by hazardous mosquitoes.
The results obtained were as follows.
1) The higher titer (1:240) of HI antibody was induced to swine, rabbits and chicks by two times injections of 1 ml of inactivated Japanese encephalitis vaccine with complete adjuvant, than that without adjuvant, and titer of HI antibody (1:53) showed itself 46 days after 1st injection. The neutralizing antibodies in the serum of swine, and rabbit obtained by the vaccination were proportional to HI antibodies.
2) In rabbits, the group vaccinated with inactivated vaccine mixed with incomplete adjuvant yielded lower HI antibody than the group of complete adjuvant, but yielded higher HI antibody than the non-vaccinated group. Therefore this method, almost free from side effects, can be used as the vaccination.
3) It was found on 27th of August that HI antibodies of swinewere increased by natural infection. And it was recognized that 2-mercaptoethanol resistant antibodies were prcduced by vaccination with complete adjuvant as well as vaccination without complete adjuvant. However 2-mercaptoethanol sensitive antibodies were produced in the swine of the non-vaccinated group by natural infection.