Vaccination with complete adjuvant-added inactivated virus vaccine of Japanese encephalitis to swine for preventing viremia (with specific reference to the effect of vaccination on viremia; epidemiological study on Japanese encephalitis. 35).

As to trial toward the elimination of Japanese encephalitis virus in natural surroundings, pigs received inoculation of inactivated Japanese encephalitis vaccine supplemented with complete Freund’s adjuvant twice at one-week interval. Effect of adjuvant supplement on the magnitude of antibody and also prevention of viremia caused by natural infection by antibody induced with vaccine were investigated. The results of this study are summarized as follows. 1. In the group of pigs inoculated with vaccine containing adjuvant, titer of hemoagglutination inhibiting and neutralizing antibodies was higher than those inoculated with vaccine alone and their high titer persisted. 2. With respect to natural infection of pigs, on August 22 when the pigs were thought to have been infected, there was observed a rise in antibody titers. And on antibody formed in those pigs inoculated with vaccine with or without adjuvant proved to be all 2-ME resistant type, whereas the antibodies produced in control group were 2-ME sensitive antibody. 3. Viremia was detected in the blood of pigs naturally infected, but it was not demonstrated pigs inoculated with vaccine supplemented with adjuvant or without adjuvant. The virus of pig blood which was inoculated into suckling mouse brain and was separated after low suckling passage mouse was supposed to be JaGAr strain from optimum hydrogen ion concentration of its hemoagglutination reaction. 4. Effect of vaccination on antibody response of pigs having maternal antibody was not recognized. ∗PMID: 4334578 [PubMed indexed for MEDLINE] Copyright c ©OKAYAMA UNIVERSITY MEDICAL SCHOOL Acta Med. Okayama 24, 579-587 (1970) VACCINATION WITH COMPLETE ADJUVANT-ADDED INACTIVATED VIRUS VACCINE OF JAPANESE ENCEPHALITIS TO SWINE FOR PREVENTING VIREMIA (WITH SPECIFIC REFERENCE TO THE EFFECT OF VACCINATION ON VIREMIA; EPIDEMIOLOGICAL STUDY ON JAPANESE ENCEPHALITIS 35) Masana OGATA, Yutaka NAGAO, Fumihiko JITSUNARI, Ritsuko KIKUI* and Naoji KITAMURA* Department of Public Health, Okayama University Medical School and *Institute of Hygiene, Okayama Prefecture, Okayama, Japan (Director: Prof. M. Ogata) Received for publication, November 9, 1970 Many ecologic studies 0,2) of Japanese encephalitis (jE) virus have recognized that swine in Japan are naturally infected in high incidence and are an important natural source of virus for Culex tritaeniorhynchus proved to be the vector mosquito. Therefore, it is necessary to prevent viremia in swine in order to eliminate the natural source of infection. For this purpose, we tried a method of vaccination using inactivated JE virus vaccine, but the antibody response was found very low. Freund's adjuvant was widely used for yielding high antibody in rabbits and guinea pigs (3-6). And we developed a method of vaccination using inactivated JE virus vaccine supplemented with Freund's complete adjuvant in 1968 (7). In the previous report (7, 8), we recognized that swine inoculatedJE vaccine supplemented with complete adjuvant showed higher titers of hemoagglutination-inhibiting (HI) and neutralizing (NT) antibody than those swine inoculated JE virus alone. In the present study, we examined effects of inactivated JE vaccine supplemented with Freund's complete adjuvant on antibody response of swine having trace or lack of antibody by HI and NT tests. And we also tested whether occurrence of viremia in swine caused by natural infection can be protected by antibody induced with inoculation of vaccine or not. In addition to this, the effect of vaccination on swine having maternal HI antibody was conducted. MATERIALS AND METHODS Materials; JE vaccine; JE vaccine for animal use (formalin inactivated vaccine, containing 0.01 wIv % of ethyl-mercury thiosalicylic acid, sodium salt) was used.