Immune Reaction of the Vaccinated Hamsters with Combined Hantaan-Puumala Vaccine

ABSTRACT

A large number of viruses belonging to Genus Hantavirus in Family Bunyaviridae are etiologic agents for hemorrhagic fever with renal syndrome (HFRS), or hantavirus pulmonary syndrome (HPS). Hantaan (HTN), Seoul (SEO), Belgrade (BEL), Puumala (PUU) serotype viruses are well known causative agents for HFRS in Eurasian continent. Among those viruses Hantaan and Seoul serotypes are well known to cause HFRS in Korea, but there are some sporadic incidence by other than Hantaan or Seoul viruses. Recently we have developed the combined Hantaan-Puumala virus vaccine to prevent world-wide occurring HFRS. This combined vaccine is formalin inactivated, suckling mouse and suckling hamster brain extracts for Hantaan and Puumala viruses, respectively. Protein contents of this purified candidate vaccine is 27 microgram/ml, which contains 1,024 ELISA antigen units to each virus, but content of myelin basic protein which is causing experimental allergic encephalomyelitis is legs than 0.1 ng/ml. Thirty hamsters were given twice at one month interval intra-muscularly and bled on 30 days after each vaccination from retro-orbital sinus vein. Antibody titers were tested against 5 major serotype viruses, Hantaan, Seoul, Belgrade, Puumala and Sin Nombre viruses by IFA and PRNT. The mean IF antibody titers on 30 days after primary shot were 78.4, 68.8, 68.8, 37.9, and 15.6; mean neutralizing antibody titers were 65.4, 12, 6.1, 65.6 and 0.5 against Hantaan, Seoul, Belgrade, Puumala and Sin Nombre viruses, respectively. The mean IF antibody titers on 30 days after booster shot were 686.9, 567.5, 550.4, 516.3, and 430.9; and neutralizing antibody titers were 710.8, 41.9, 24.3, 409.9, and 1.6 against Hantaan, Seoul, Belgrade, Puumala and Sin Nombre viruses, respectively.