Immunity and the level of neutralization antibodies in foals and mares vaccinated with a modified live-virus rhinopneumonitis vaccine
Dutta, S.K.; Shipley, W.D.
American Journal of Veterinary Research 36(4 Part 1): 445-448
1975
ISSN/ISBN: 0002-9645 PMID: 164808 Document Number: 86739
Foals on farms '1' and '2' and mares on farms '1' and '3' were inoculated with a commercially available rhinopneumonitis vaccine and then tested for antibodies and for protection against the natural infection. The serum-neutralization antibody titres against equine herpesvirus type 1 were 1:8 or less in the majority of foals and 1:16 or higher in about 10%. Nasal secretory antibody in the foals (farm 2) was less than 1:4. Vaccinated foals did not show any apparent respiratory tract infection for about six months, but then an outbreak of respiratory tract disease appeared on farm 1 involving three foals. From each of these three foals a herpesvirus was isolated. On farm 1, about half of the vaccinated mares aborted, but there were no abortions on farm 3. Isolations of herpesvirus were made from five of the six aborted fetuses (farm 1). Antibody titres of pregnant mares at the time of foaling were high.