Immunogenicity of an inactivated bovine herpesvirus type 5 strain defective in thymidine kinase and glycoprotein E Imunogenicidade de uma cepa inativada do herpesvírus bovino tipo 5 defectiva na timidina quinase e glicoproteína E

• Published in: Pesquisa veterinária brasileira 2010-01, Vol.30 (1), p.57-62
• Main Authors: Mário Celso S. Brum, Luizinho Caron, Shafiqul I. Chowdhury, Rudi Weiblen, Eduardo Furtado Flores
• Format: Article
• Language: English
• Subjects: differential vaccine; DIVA; glicoproteína E; glycoprotein E; recombinant vaccine; Vaccines; vacina diferencial; Vacinas; vírus recombinante
• ISSN: 0100-736X; 1678-5150
• DOI: 10.1590/S0100-736X2010000100009

The immunogenicity of an inactivated, experimental vaccine based on a bovine herpesvirus type 5 strain defective in thymidine kinase and glycoprotein E (BoHV-5 gE/TKΔ) was evaluated in cattle and the results were compared with a vaccine containing the parental BoHV-5 strain (SV507/99). To formulate the vaccines, each virus (wildtype SV507/99 and BoHV-5 gE/TK∆) was multiplied in cell culture and inactivated with binary ethyleneimine (BEI). Each vaccine dose contained approximately of 10(7.5) TCID50 of inactivated virus mixed with an oil-based adjuvant (46:54). Forty calves, 6 to 9-months-old, were allocated into two groups of 20 animals each and vaccinated twice (days 0 and 22pv) by the subcutaneous route with either vaccine. Serum samples collected at day 0 and at different intervals after vaccination were tested for virus neutralizing (VN) antibodies against the parental virus and against heterologous BoHV-5 and BoHV-1 isolates. The VN assays demonstrated seroconversion to the respective homologous viruses in all vaccinated animals after the second vaccine dose (mean titers of 17.5 for the wildtype vaccine; 24.1 for the recombinant virus). All animals remained reagents up to day 116 pv, yet showing a gradual reduction in VN titers. Animals from both vaccine groups reacted in similar VN titers to different BoHV-1 and BoHV-5 isolates, yet the magnitude of serological response of both groups was higher against BoHV-5 field isolates. Calves vaccinated with the recombinant virus did not develop antibodies to gE as verified by negative results in a gE-specific ELISA, what would allow serological differentiation from naturally infected animals. Taken together, these results indicate that inactivated antigens of BoHV-5 gE/TK recombinant virus induced an adequate serological response against BoHV-5 and BoHV-1 and thus can be used as an alternative, differential vaccine candidate.A imunogenicidade de vacina experimental inativada, produzida com uma cepa do herpesvírus bovino tipo 5 defectiva nos genes da timidina quinase e glicoproteína E (BoHV-5 gE/TKΔ) foi avaliada em bovinos e o resultado foi comparado com a resposta induzida pela cepa parental do BoHV-5 (SV507/99). Para a formulação da vacina, cultivos de células infectados com cada um dos vírus (SV507/99 ou BoHV-5 gE/TKΔ) foram inativados com etilenamina binária. Cada dose de vacina continha aproximadamente 107,5 TCID50 de um dos vírus inativados emulsionado em adjuvante oleoso (46:54). Quarenta bezerros de ra