The present study evaluated the immunogenicity of six commercial vaccines containing inactivated antigens of bovine herpesvirus-1 (BoHV-1): one Brazilian (BR), a North American (US), two Uruguaians (UR1 e UR2) and two Argentinians (ARG1 e ARG2).Groups of 6 to 9 naive calves were vaccinated twice in a 21-days interval with each one of the vaccines. The sera collected 21 days after the second dose were tested for BoHV-1 and BoHV-5-specific neutralizing (VN) antibodies. With the exception of US and UR1 vaccines, the other vaccines induced low VN titers in most animals. The titers induced by the US vaccine (geometric mean, GMT=38) were higher than the others (P<0.05). The UR1 vaccine induced titers (GMT=20.2) higher than those induced by BR (GMT=8.7), UR2 (GMT=7.3), ARG1 (GMT=10) and ARG2 (GMT=6.3) vaccines (P<0.05), which did not differ among them (P>0.05). The US vaccine induced titers compatible with protection (> 16) in 7 animals (87.5%). The other vaccines induced titers below 16 in 62.5% (5 out of 8, BR), 33.3% (4 out of 9, UR1), 75% (6 out of 8, UR2) and 83.3% of the calves (5 out of 6, ARG2). The ARG1 vaccine showed the poorest performance, only three animals (37.5%) seroconverted, yet in low titers. The neutralizing activity against BoHV-5, an antigenicaly related virus, was lower than to BoHV-1 in all groups, however, for BR, ARG1 and ARG2 the differences were not significant (P>0.05). The low VN titers induced by most vaccines, even being tested at an ideal time interval, indicate the need for reviewing the criteria for vaccine production, licensing and import as well.
BoHV-1; BoHV-5; commercial vaccines; Brazil
