Adsorption of colostral antibodies against classical swine fever, persistence of maternal antibodies, and effect on response to vaccination in baby pigs.
OBJECTIVE
To determine kinetics of antibody absorption, persistence of antibody concentrations, and influence of titers on vaccination of baby pigs with a vaccine against classical swine fever (CSF).


METHODS
15 sows and their litters.


METHODS
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 initial suckling. Samples were assayed for CSF antibodies, using a serum neutralizing (SN) test. A second experiment included 33 baby pigs vaccinated as follows: 10 prior 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 were vaccinated when 7 weeks old, and 15 pigs were not vaccinated. At 10 weeks of age, pigs were challenge-exposed with virulent CSF virus. Blood samples were collected and assayed for CSF antibodies and p125 antigen and p125 antibodies.


RESULTS
CSF antibodies were detected in pigs beginning 2 hours after suckling. Colostral antibodies persisted for > 7 weeks (half-life, 79 days). Vaccination of pigs before suckling provided effective protection from severe disease after challenge-exposure. However, vaccination of neonates with antibody 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
Vaccination before ingestion of colostrum conferred good protection against CSF in baby pigs. Vaccination of 7-week-old pigs that had decreasing concentrations of passively acquired antibodies was efficacious.
Vandeputte
J
J
Regulatory Affairs International, Merial SAS, Lyon, France.
Too
H L
HL
Ng
F K
FK
Chen
C
C
Chai
K K
KK
Liao
G A
GA
D000327:Adsorption; D000818:Animals; D000831:Animals, Newborn; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D000956:Antigens, Viral / Q000097:blood; D006691:Classical Swine Fever / Q000276:immunology* / Q000378:metabolism / Q000517:prevention & control; D006692:Classical Swine Fever Virus / Q000276:immunology*; D003126:Colostrum / Q000276:immunology*; D005260:Female; D006207:Half-Life; D007112:Immunity, Maternally-Acquired / Q000276:immunology; D007700:Kinetics; D011897:Random Allocation; D012044:Regression Analysis; D013552:Swine; D014611:Vaccination / Q000662:veterinary*; D014765:Viral Vaccines / Q000276:immunology / Q000493:pharmacokinetics* / Q000592:standards
D000914:Antibodies, Viral; D000956:Antigens, Viral; D014765:Viral Vaccines