Humoral immune response in capuchin monkeys (Cebus apella) after vaccination with inactivated suckling mouse brain rabies vaccine: comparison of two schedules of immunization

Abstract

Two groups of adult capuchin monkeys (Cebus apella) were vaccinated i.m. against rabies with inactivated suckling mouse brain rabies vaccine (SMBV), at the Zoo Park Foundation in São Paulo, SP, Brazil. The animals had not been immunized against rabies at any time before. Group I consisted of nine animals, to which were given three 1.0mL doses on days 0 and 30, plus a booster on day 210. Group II comprehended ten animals, to which were given two 1.0mL doses: one, on day 0 and, another, a booster, on day 210. The blood samples were collected on days 0, 30, 60, 90, 150, 210, 240, 300 and 365, being the titrated neutralizing antibodies determined by the simplified fluorescent focus inhibition technique. The vaccine induced immune responses with neutralizing antibody titers above 0.5 IU/m in both groups of capuchin monkeys; however, they were short, lasting 54.9 ± 57.0 days and 36.1 ± 60.2 days in Groups I and II, respectively, after primo-vaccination, and 62.6 ± 74.0 and 86.4 ± 61.5 days in Groups I and II, respectively, after a booster. No statistically significant differences were observed out between the two groups studied (p >; 0.05).