Vaccine immune response and interference of colostral antibodies in calves vaccinated against rabies at 2, 4 and 6 months of age born from antirabies revaccinated females.

Considering the high prevalence of rabies in cattle, we aimed to evaluate the interference of colostral antibodies transferred to calves after birth and the benefit of administering an antirabies vaccination in two-month-old calves compared to vaccinating at 4 and 6 months of age. Calves born from females revaccinated against rabies during the third trimester of pregnancy were studied. Forty-eight hours after parturition, blood samples from dams and offspring were collected, and antirabies neutralizing antibody titers were analyzed using the Rapid Focus Fluorescent Inhibition Test. We found that all calves had similar titers of antibodies transferred through the colostrum. Furthermore, none of the calves presented a satisfactory serological response after the first vaccination, but all had an appropriate response after revaccination. This study demonstrates that antirabies vaccination should be recommended for calves at two months of age in endemic and epizootic situations.

Importance of antirabies revaccination for an adequate antirabies protection in bovine newborns.

The transfer of antirabies immunoglobulins in cows that were prime vaccinated and cows that were revaccinated against rabies correlated to the serum titers in their offspring was evaluated. The results demonstrated that revaccination against rabies during pregnancy induces neutralizing antibody titers at a protective level that are transferred directly to calves through colostrum and reinforce the importance of revaccination for improved colostral antibody transfer and offspring protection against rabies.

Perfil de aglutininas anti-Leptospira em bezerras búfalas vacinadas com bacterina pentavalente comercial contra leptospirose / Serological response anti-Leptospira in female buffalo calves vaccinated with commercial pentavalent bacterin against leptospirosis

Avaliou-se o perfil sorológico de 17 bezerras búfalas vacinadas nos dias zero, 30 e 210 com bacterina pentavalente comercial contra leptospirose, empregando-se a prova de soroaglutinação microscópica com antígenos vivos, durante o período de 360 dias. Utilizaram-se quatro bezerras-controle, e todos os animais foram negativos no dia zero. Nos animais vacinados, foram observadas reações aos 60 dias para todos os sorovares, associadas a títulos máximos para Canicola, Grippothyphosa e Pomona. No 90° dia, houve declínio acentuado dos títulos para todos os sorovares e ausência de títulos para Hardjo. Nos dias 120°, 150°, 180° e 210°, ocorreram oscilações de títulos para todos os sorovares. No 240° dia, foram encontrados títulos máximos para Hardjo, elevação para os outros sorovares e ausência de título para Canicola. Nos dias 270°, 300° e 330°, foi observado declínio gradativo dos títulos. No 360° dia, foram encontrados títulos residuais para Icterohaemorrhagiae, Grippothyphosa e Pomona e ausência de reação para os outros sorovares. Inferiram-se a reduzida persistência dos títulos vacinais mesmo após o reforço e revacinação e a baixa interferência da vacinação no diagnóstico sorológico.

The serological profile of 17 buffalo calves vaccinated at zero, 30 and 210 days of age using a commercial pentavalent bacterin against leptospirosis was evaluated using microscopic seroagglutination, during 360 days post-vaccination (PV). Four non-vaccinated buffalo calves were used as control. All animals studied showed a negative reaction at day zero. In the vaccinated animals, the serological responses for all serovars were detected at the 60th day PV, with maximum agglutinin levels for Canicola, Grippothyphosa and Pomona. The antibody levels decreased for all serovars at day 90 with zero titters for Hardjo serovar. At days 120, 150, 180 and 210 PV were observed oscillations of titters for all serovars. At day 240, maximum antibody levels for Hardjo, an increase of titters for others serovars and no reaction for Canicola were found. At days 270, 300 and 330 a gradual decrease of antibody levels were observed. At day 360 residual titters for Icterohaemorrhagiae, Grippothyphosa and Pomona, and no reaction for the other serovars were observed. The results indicate a short persistency of seric agglutinin levels induced by vaccination, even after improvement and preparation of the vaccine reinforcement, and low interference of vaccination with serodiagnosis.