Adsorption of colostral antibodies against classical swine fever, persistence of maternal antibodies, and effect on response to vaccination in baby pigs
J. Vandeputte et al., Adsorption of colostral antibodies against classical swine fever, persistence of maternal antibodies, and effect on response to vaccination in baby pigs, AM J VET RE, 62(11), 2001, pp. 1805-1811
Objective-To determine kinetics of antibody absorption, persistence of anti
body concentrations, and influence of titers on vaccination of baby pigs wi
th a vaccine against classical swine fever (CSF).
Animals-15 sows and their litters.
Procedure-Farrowings were supervised. Initial time of suckling was recorded
. In the first experiment, blood samples were collected at farrowing, 2 and
4 hours after suckling, and hourly until 10 hours after ink tial suckling.
Samples were assayed for CSF antibodies, using a serum neutralizing (SN) t
est. A second experiment included 33 baby pigs vaccinated as follows: 10 pr
ior to ingestion of colostrum, 18 between 1 and 4 hours after ingestion of
colostrum, and 5 at 12 hours after ingestion of colostrum. Fourteen pigs we
re vaccinated when 7 weeks old, and 15 pigs were not vaccinated. At 10 week
s of age, pigs were challenge-exposed with virulent CSF virus. Blood sample
s were collected and assayed for CSF antibodies and p125 antigen and p125 a
ntibodies.
Results-CSF antibodies were detected in pigs beginning 2 hours after suckli
ng, Colostral antibodies persisted for > 7 weeks (half-life, 7.9 days). Vac
cination of pigs before suckling provided effective protection from severe
disease after challenge-exposure. However vaccination of neonates with anti
body titers was not effective, because 19 of 23 (82%) pigs succumbed after
challenge-exposure, All pigs vaccinated when 7 weeks old resisted challenge
-exposure, whereas all unvaccinated control pigs succumbed.
Conclusions and Clinical Relevance Vaccination before ingestion of colostru
m conferred good protection against CSF in baby pigs. Vaccination of 7-week
-old pigs that had decreasing concentrations of passively acquired antibodi
es was efficacious.