Humoral and cellular immune responses in swine after vaccination with inactivated pseudorabies virus
Gutekunst, D.E.; Pirtle, E.C.
American Journal of Veterinary Research 40(10): 1343-1346
1979
ISSN/ISBN: 0002-9645 PMID: 230755 Document Number: 146162
Humoral and cellular immune responses were compared in seronegative swine vaccinated twice, 2 wk apart, with an inactivated pseudorabies virus (PRV) vaccine or lipid-conjugated PRV combined with the inactivated vaccine. Vaccinated and contact control swine were challenge-exposed 14 wk after vaccination. Precipitating antibody [Ab] was detected by the microimmunodiffusion test in 92% of swine 7 days after the 1st vaccination and all animals were microimmunodiffusion test-positive 14 days after vaccination. Low concentrations of virus-neutralizing (VN) Ab were present in 50% of the vaccinated swine at 7 days and all had VN Ab 14 days after vaccination. The VN Ab reached a high concentration 3-4 wk after vaccination and remained constant thereafter until challenge exposure; an anamnestic Ab response then occurred. Detectable humoral Ab were not present in the control swine until after challenge exposure, at which time primary Ab response occurred. Cellular immune responses were detected in 50% of the vaccinated swine by the leukocyte migration-inhibition test at 7 days after vaccination; all vaccinated swine had a positive response 14 days after vaccination. Inhibition increased to a maximum at 5 wk after vaccination, then slowly declined. Inhibition was slightly higher and more sustained in swine given the combined vaccine. Inhibition of leukocyte migration was observed 4 days after challenge exposure of the control swine. Concentrations of immunoglobulin (Ig)G fluctuated in vaccinated and control swine. Concentrations of IgG were markedly increased in vaccinated swine 1 wk after the 2nd vaccination and in vaccinated and control swine 1 wk after challenge exposure. Control swine excreted more PRV from their nasal passages in larger quantities and for a longer period than vaccinated swine after challenge exposure.