Immune response of sows vaccinated with attenuated transmissible gastroenteritis virus (TGEV) and recombinant TGEV spike protein vaccines and protection of their suckling pigs against virulent TGEV challenge exposure.
OBJECTIVE
To compare recombinant transmissible gastroenteritis virus (TGEV) spike protein, (SP) R2-2, with attenuated live virus (ALV) vaccine in sows during late pregnancy.


METHODS
13 TGEV-seronegative sows and their pigs.


METHODS
At prepartum weeks (PPW) 6 and 4, sows of groups 1 and 2 received ALV via the oral/intranasal (O/IN) route. At PPW 2, group-1 sows received ALV IM and group-2 sows received SPR2-2 IM. Group-3 sows received SPR2-2 IM at PPW 4 and ALV O/IN at PPW 2. Sows of group 4 (negative controls) were inoculated O/IN with mock-infected ST cell fluids at PPW 6 and 4 and IM with Sf9 cell lysates at PPW2 (n = 2), or IM with Sf9 cell lysates at PPW4 and O/IN with mock-infected ST cell fluids at PPW2 (2). Serum, colostrum, and milk samples were tested for antibody to TGEV, and a lymphoproliferative (LP) assay was done on blood mononuclear cells. Suckling pigs were challenge exposed with virulent TGEV.


RESULTS
Sows of groups 1 and 2 had higher IgG and significantly higher antibody titers in colostrum; their pigs had significantly higher serum antibody titer. At challenge exposure of their pigs, LP responses of group-2 sows were significantly higher than those of sows in the other 3 groups. Mean pig mortality ranged from 43 (group 2) to 92% (group 4). Significant negative correlations were observed among litter mortality and sow LP response, colostral titer, and pig serum titer at time of challenge exposure.


CONCLUSIONS
In sows vaccinated twice with attenuated live TGEV, the recombinant SPR2-2 administered IM may be comparable to ALV administered IM as a booster. Vaccination failed to provide complete protection to suckling pigs after challenge exposure.
Park
S
S
Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center (OARDC), Ohio State University, Wooster 44691, USA.
Sestak
K
K
Hodgins
D C
DC
Shoup
D I
DI
Ward
L A
LA
Jackwood
D J
DJ
Saif
L J
LJ
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000917:Antibody Formation; D000956:Antigens, Viral / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000821:virology; D005260:Female; D005761:Gastroenteritis, Transmissible, of Swine / Q000276:immunology* / Q000517:prevention & control; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D011270:Pregnancy, Animal / Q000276:immunology*; D013552:Swine; D005760:Transmissible gastroenteritis virus / Q000276:immunology*; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic; D014764:Viral Proteins / Q000276:immunology*; D014765:Viral Vaccines
D000914:Antibodies, Viral; D000956:Antigens, Viral; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic; D014764:Viral Proteins; D014765:Viral Vaccines; C064484:spike protein S, Transmissible gastroenteritis virus