Immunoreactivity of sera of calves vaccinated with Haemorrhagic septicaemia vaccine to outer membrane proteins of Pasteurella multocida (B:2) strain P₅₂

Outer membrane proteins (OMPs) of Pasteurella multocida strain P52 were purified by immunoaffinity chromatography (IAC) using pre-challenge serum from HS vaccinated cattle-calves. IgG antibody titers of pre-challenge sera from HS vaccinated calves surviving and succumbing to direct challenge with virulent culture were determined against formalized P52 cells, P52 crude cell lysate, and OMPs of P52 purified by IAC. It was observed that OMP antigens were involved with protective response in calves and indirect ELISA test using lAC purified antigens can be developed for in vitro potency determination of Haemorrhagic septicemia (HS) vaccines.