Immunogenicity and protective efficacy of a gE, gG and US2 gene-deleted bovine herpesvirus-1 (BHV-1) vaccine

The efficacy and safety of a gene-deleted bovine herpesvirus-l (BHV-1) vacc ine was determined in a bovine herpesvirus challenge trial in calves, Three different doses of the vaccine were administered intramuscularly at 10(5), 10(6) and 10(7) PFU/ml and compared to a commercial vaccine and non vaccin ated control calves. Challenge was performed by intranasal aerosolization w ith the Cooper strain of BHV-1 (3 x 10(4) PFU/ml). The non-vaccinated calve s shed significantly (P < 0.05) more virus than all other groups on days 4, 8 and 10 post challenge. By day 14 post challenge, antibody titers for BHV -1 of calves vaccinated with 107 PFU/ml were significantly (P < 0.05) highe r than the commercial or non-vaccinated calves. Clinical scores of non-vacc inated calves were significantly (P < 0.05) higher than all other groups on days 4-14 post challenge. With both radioimmunoprecipitation and competiti ve enzyme-linked immunosorbent assays (C-ELISA), calves in the gene-deleted vaccine groups mounted comparable specific responses against gB, gC and go post vaccination as calves in the commercial vaccine group, but in a dose dependent manner. These data suggest that the gene-deleted BHV-1 vaccine te sted may be used as an effective vaccine in controlling BHV-1 infections. ( C) 1999 Elsevier Science Ltd. All rights reserved.