Short duration of neutralizing antibody titers after pre-exposure rabies vaccination with suckling mouse brain vaccine

Abstract

The human anti-rabies pre-exposure treatment currently used in Brazil, employing a 1-ml dose of suckling mouse brain vaccine (SMBV) administered on days 0, 2, 4 and 28, was compared to an alternative treatment with two 1 ml-doses on day 0, and one 1 ml-dose injected on days 7 and 21. The latter induced higher virus-neutralizing antibody (VNA) titers on day 21. Both Brazilian rabies vaccines produced with PV or CVS rabies virus strains were tested. Two additional volunteer vaccinee groups, receiving the pre-exposure and the abbreviated postexposure schedules recommended by the WHO using cell-culture vaccine (CCV) produced with PM rabies virus strain, were included as reference. The VNA were measured against both PV and CVS strains on days 21, 42 and 180 by the cell-culture neutralization microtest. The PV-SMBV elicited higher seroconversion rates and VNA by day 21 than the CVS-SMBV. Both, however, failed to induce a long-term immunity, since VNA titers were <0.5 IU/ml on day 180, regardless of the schedule used. Cell-culture vaccine always elicited very high VNA on all days of collection. When serum samples from people receiving mouse brain tissue were titrated against the PV and CVS strains, the VNA obtained were similar, regardless of the vaccinal strain and the virus used in the neutralization test. These results contrast with those obtained with sera from people receiving PM-CCV, whose VNA were significantly higher when tested against the CVS strain.

Antibody response in cattle after vaccination with inactivated and attenuated rabies vaccines

“…Consequently, homology only existed between the vaccinal virus strain and the target strain for those serum samples from bovines immunized with IPVvac when neutralization assay was used for testing. We have recently reported that people receiving PM-cellculture had significantly higher VNA titers when their serum samples were tested against CVS strain than they did when they were tested against PV strain 21 , corroborating this supposition.…”

Evaluation of Rapid Neutralizing Antibody Detection Test against Rabies Virus in Human Sera

“…This may be the result of inadequate courses of vaccine or a reduction of NAb levels after vaccination. The reduction of NAb levels was also reported by Zanetti and colleagues, who showed that after 180 days post vaccination, seroconversion could not be found in 60% of people who were vaccinated with four doses of suckling mouse-derived vaccine on day 0-0-7-21 [ 12 ]. Recently, atypical rabies transmission from animals to humans associated with the butchering and processing of dog meat has been reported in several parts of the world [ 4 , 13 – 15 ].…”

Resposta imune humoral de macacos-pregos (Cebus apella) após vacinação com vacina anti-rábica inativada produzida em cérebros de camundongos lactentes: comparação de dois esquemas de imunização

“…The inactivated suckling mouse brain rabies vaccine (SMBV) presents an adequate antigenic mass, producing immunity with few adverse side effects in the majority of the animal population 4 . Since a low immunogenic response had been observed in studies undertaken with individuals and animals immunized with the inactivated suckling mouse brain rabies vaccine, a booster dose was found necessary 5,6,7,8,9 . The SMBV is used in Brazilian national vaccination campaigns against rabies, in dogs and cats, carried out, annually, in September.…”