Effect of complete adjuvant on vaccination of live attenuated Japanese encephalitis vaccine to swine for preventing viremia. 39. Epidemiological studies of J.E.

In an attempt to eliminate Japanese encephalitis virus in natural surroundings, pigs having maternal antibody were given inoculation of live-attenuated Japanese encephalitis vaccine and injection of Freund’s complete adjuvant simultaneously. Titer of hemoagglutination inhibiting antibodies of pigs inoculated with live attenuated vaccine and complete adjuvant, was higher than that inoculated with vaccine alone and its titer persisted. ∗PMID: 4334469 [PubMed indexed for MEDLINE] Copyright c ©OKAYAMA UNIVERSITY MEDICAL SCHOOL Acta Merl. Okayama 25, 71-75 (1971) EFFECT OF COMPLETE ADJUVANT ON VACCINATION OF LIVE ATTENUATED JAPANESE ENCEPHALITIS VACCINE TO SWINE FOR PREVENTING VIREMIA (REPORT 39 OF EPIDEMIOLOGICAL STUDIES OF J. E.) Masana OGATA, Yutaka NAGAO, Ritsuko KIKUI, * Naoji KITAMURA, * Hajime ARIYASU, ** Hajime KIMOTO** and Hisashi HAGAYA** Department of Public Health, Okayama University Medical School, Okayama, Japan (Director: Prof. M. Ogata) Received for publication, January 12, 1971 Many ecologic studies (1. 2) of Japanese encephalitis (jE) virus have recognized that swine in Japan is naturally infected in high incidence and is an important natural source of virus for Culex tritaeniorhynchus proved to be the vector mosquitoes. Therefore, it is first necessary to prevent viremia in swine to eliminate the natural source of infection. Freund's complete adjuvant was widely used for yielding high antibody in rabbits and guinea pigs (3-6), And we have reported that the swine inoculated inactivated JE vaccine supplemented with complete adjuvant showed higher titers of hemoagglutination inhibiting (HI) and neutralizing (NT) antibody, than those swine inoculated JE virus alone (7), And also we described that occurrence of viremia in swine caused by natural infection can be protected by antibody induced by inoculation of vaccine (8), On the other hand, KODAMA, SASAKI, and INOUE (9) inoculated pigs with live-attenuated mutant strain (Mukai strain) of JE virus and found that the strain produced no detectable viremia and was able to evoke both HI and NT in colostrum deprived pigs after a single subcutaneous injection. However, the antibody response in the swine having maternal antibody by the use of live-attenuated vaccine (Mukai strain) is found to be absent (0), In the present study, the effect of complete adjuvant on antibody response of swine, having maternal antibody and receiving inoculation * Institute of Hygiene, Okayama Prefecture. ** Health Center of Domestic Animals, Wake District of Okayama Prefecture. 71 1 Ogata et al.: Effect of complete adjuvant on vaccination of live attenuated Produced by The Berkeley Electronic Press, 1971 72 M. OGATA, Y. NAGAO, R. KIKUI, N. KITAMURA, H. ARIYASU, H. KIMOTO and H. HAGAYA with a new strain of live-attenuated vaccine was investigated. This report describes briefly our results. MATERIALS AND METHODS Materials IE vaccine: Live-attenuated vaccine prepared by tissue culture was donated by Dr. KAWAKUBO of Nissei Research Institure. The titer showed 109/ml TCID50 units for HK cells. Pigs: Pigs, 1.5 month old, showing 1 : 40 of HI antibody titer were employed. These animals were kept on Wake district, Okayama Prefecture, where JE virus is epidemic every year. Method Vaccination: In the group inoculated with JE vaccine alone, pigs were inoculated once with 3 ml live-attenuated JE vaccine intramuscularly in the neck. In the group inoculated with JE vaccine and injected with complete adjuvant, pigs were inoculated with 3 mllive-attenuated JE vaccine in the neck, and injected simultaneously with 3 ml complete adjuvant intramuscularly, on the other side of the neck. Collection of blood: The blood of pigs was obtained from auricular vein at oneweek interval after inoculation. Determination of HI antibodies in the serum: Antibody titers in the sera of pigs were tested by the technique of the HI test, following the modified method of CLARK and CASALS (11). The hemagglutination antigen used was JaGAr strain (Takeda Co.) purified with ether after suckling mouse brain passage.