USE OF AN UNCAPSULATED HAEMOPHIL US PARASUIS VACCINE IN PIGS

摘要

Control of Haemophilus parasuis infections depends on two major factors: early diagnosis of infection and development of immunity against the agent. To date there is no universally effective vaccine against H. parasuis. This is in part due to the factthat there are 15 antigenically distinct serotypes as well as antigenic subtypes of some serotypes. Vaccination with a killed whole cell vaccine prepared from one serovar does not always confer protection against other serotypes, or even against subtypes of the same serovar. Virulent H. parasuis strains tend to have similar OMP profiles, and also to induce effective protection against both homologous and heterologous H. parasuis challenges. Considering that the majority of H. parasuis virulent strainshave similar OMP patterns and that protective immunity is mainly related to the recognition of these sub-capsular antigenic determinants, vaccination of naive animals using an uncapsulated virulent H. parasuis strain would be most likely to protect against homologous and heterologous challenges. In the present study, the induction of protective immunity by an uncapsulated H. parasuis killed vaccine against homologous and heterologous challenge was evaluated.