Neutralizing antibodies to bovine herpesviruses types 1 (BHV-1) and 5 (BHV-5) induced by an experimental, oil-adjuvanted, BHV-1 vaccine

English. An experimental oil-adjuvanted, inactivated vaccine against bovine herpesvirus type 1 (BHV-1.1), was produced and evaluated in its capacity to induce neutralizing antibodies against bovine herpesvirus type 1 (BHV-1, subtypes 1.1 and 1.2) and bovine herpesvirus type 5 (BHV-5). Cattle were vaccinated and revaccinated 90 days later. Antibodies were measured at days 0, 30, 90, 120, 180, 270 and 450 days after the first dose of vaccine (DPV). Antibody titres to BHV-1.1 and BHV-1.2 were significantly higher than to BHV-5 throughout the experiment. While all calves seroconverted to BHV-1.1 and BHV-1.2 after the first dose of vaccine, only two out of 23 (8,7%) calves seroconverted to BHV-5. However, after the booster injection all animals seroconverted to the three virus types. At 450 DPV, 79% (15/19 cattle) and 84% (16/19) were still positive for antibodies to BHV 1.1 and BHV 1.2, whereas 50% (10/19) of the calves remained seropositive for BHV-5. It was concluded that although a potent BHV-1 vaccine may induce crossreactive neutralizing antibodies to BHV-5, the levels of such antibodies are significantly lower and of shorter duration than antibodies to BHV-1.1 or BHV-1.2.

Portuguese. Foi avaliada a capacidade de uma vacina experimental oleosa inativada contra o herpesvírus bovino tipo 1 induzir anticorpos contra o herpesvírus bovino tipo 1 (BHV-1.1 e BHV-1.2) e herpesvírus bovino tipo 5 (BHV-5). Bovinos foram vacinados com duas doses de vacina, aplicadas com um intervalo de 90 dias. Foi medido o título de anticorpos nos dias 0, 30, 90, 120, 180, 270 e 450 após a primeira vacinação (DPV). Os títulos de anticorpos contra BHV-1.1 e BHV-1.2 foram significativamente maiores que os contra BHV-5, ao longo do experimento. Enquanto todos os animais soroconverteram para BHV-1.1 e BHV-1.2 após a primeira dose de vacina, apenas dois em 23 animais (8,7%) soroconverteram para o BHV-5. No entanto, após o reforço, todos os animais soroconverteram contra BHV-1.1, 1.2 e BHV-5. Aos 450 DPV, 79% (15/19 animais) e 84% (10/19) ainda se encontravam soropositivos para BHV-1.1 e BHV-1.2, enquanto apenas 50% dos animais (10/19) se demonstraram positivos contra o BHV-5. Foi concluído que, embora uma vacina com alta capacidade de indução de anticorpos contra o BHV-1 possa induzir anticorpos capazes de neutralizar o BHV-5, os níveis de tais anticorpos são significativamente mais baixos e de menor duração do que aqueles induzidos contra BHV-1.1 e BHV-1.2.