[Immunological reactivity of suckling pigs born to sows immunized against the lapinized K vaccine].
The lapinized K vaccine was used to immunize 25 five-day-old pigs and 27 ten-day-old pigs. A group of 10 pigs were also included in the experiment as controls. All animals originated from eight sows treated with a lapinized K vaccine on the 70th day of pregnancy. On the 14th day following vaccination part of the pigs of the two test groups were revaccinated. Three months later half of the immunized pigs were infected with a pathogenic swine fever virus. The remaining animals were infected then in a six months time following immunization. Systematic clinical and morphological investigations were carried out. It was concluded that the 5-day-old animals possessed much lower immunologic responsiveness to the lapinized K vaccine against swine fever as against the 10-day-old ones. Revaccination with the same vaccine on the 14th day led to a weaker immune response as compared to single vaccination. The immunity of the vaccinated 10-day-old pigs, originating from sows that had been immunized with the same vaccine during pregnancy, lasted about three months.