Safety and efficacy of a classical swine fever subunit vaccine in pregnantsows and their offspring

In the study three groups with five pregnant sows each were used. The anima ls were vaccinated twice, 2 weeks apart, in different stages of gestation, i.e. +/-4, +/-8 and +/-12 weeks after insemination and then 14 days later, respectively. From each group of sows three litters were randomly selected and vaccinated twice, 4 weeks apart, at 5 and 9, 7 and 11, and 9 and 13 wee ks of life, respectively Blood for serological investigations by virus neut ralisation test and ELISA tests (for E-rns antibodies and for E2 antibodies , separately) was taken before immunisation, at each vaccination and 2 week s thereafter. Clinical observations shown that no local nor systemic reacti ons as well as no adverse effect on gestation occurred after vaccinations i n any of the sows. Serological tests detected a low level of antibodies aft er the first vaccination and a typical booster effect after the second one. In piglets no adverse effect of the vaccination on the body weight gain wa s found. The presence of maternally derived antibodies (MDA) in non-vaccina ted control piglets was observed up to the age of 5-13 weeks of life. The m ost evident immunological reaction was obtained in piglets vaccinated at th e age of 5 or 7 weeks of life and revaccinated 4 weeks later. The CSFV-E2 s ubunit marker vaccine tested proved to be safe for pregnant sows and immuno genic for MDA positive piglets. (C) 2000 Elsevier Science B.V. All rights r eserved.