Bouma A, De Jong M C, Kimman T G
DLO-Institute of Animal Science and Health (ID-DLO), Lelystad, The Netherlands.
Vaccine. 1997 Feb;15(3):287-94. doi: 10.1016/s0264-410x(96)00179-x.
The purpose of this study was to investigate whether maternal immunity could prevent transmission of pseudorabies virus (PRV) among pigs, and whether it reduced the effectiveness of a single or double vaccination with regard to the transmission of PRV. In five experiments, the transmission of PRV, expressed as the reproduction ratio R, was compared in groups of pigs with maternal immunity and in groups of pigs without maternal immunity. Transmission of PRV among unvaccinated pigs with maternal immunity (R = 0.2) was significantly lower than among pigs without maternal immunity (R = 6.3). Furthermore, maternal immunity in young pigs prevented transmission of PRV, as R was significantly below one. In once-vaccinated groups, PRV spread extensively among pigs with maternal immunity (R = 23), but did not spread extensively among pigs without maternal immunity (R = 0.6). In twice-vaccinated groups, transmission of PRV among pigs with maternal immunity (R = 0.6) did not differ significantly from the transmission of PRV among pigs without maternal immunity (R = 0.3). Thus, a single vaccination of pigs with PRV strain 783 at 10 weeks of age, when they still possessed maternal immunity, seemed not sufficient to prevent transmission of PRV. Virus transmission could be reduced, however, if maternally immune pigs were vaccinated twice at 10 and 14 weeks of age.
本研究的目的是调查母源免疫是否能预防猪伪狂犬病病毒（PRV）的传播，以及母源免疫是否会降低单次或两次接种疫苗对PRV传播的有效性。在五项实验中，比较了有母源免疫的猪群和无母源免疫的猪群中PRV的传播情况，以繁殖率R表示。有母源免疫的未接种疫苗的猪之间PRV的传播率（R = 0.2）显著低于无母源免疫的猪（R = 6.3）。此外，仔猪的母源免疫可预防PRV的传播，因为R显著低于1。在单次接种疫苗的猪群中，PRV在有母源免疫的猪中广泛传播（R = 23），但在无母源免疫的猪中未广泛传播（R = 0.6）。在两次接种疫苗的猪群中，有母源免疫的猪之间PRV的传播率（R = 0.6）与无母源免疫的猪之间PRV的传播率（R = 0.3）无显著差异。因此，仔猪在10周龄时仍具有母源免疫，用PRV 783株进行单次接种似乎不足以预防PRV的传播。然而，如果有母源免疫的仔猪在10周龄和14周龄时进行两次接种，则可降低病毒传播。
