Detection of humoral immune response induced in horses vaccinated with inactivated Equine Herpes Virus Vaccine

Equine herpesviruses (EHV1 and EHV4) are essential in horses. Repeated cases of infection and abortion in mares who have regularly vaccinated impetus us to determine to investigate the humoral immune response after post-vaccination with the same inactivated vaccine and the best vaccination protocol. Twelve healthy susceptible horses were divided into four groups (3 horse /group). The first group was vaccinated I/M with inactivated Equine Herpes (type 1 and 4), where each horse was inoculated with a single dose (2ml/ dose /horse). The second group was vaccinated with inactivated Equine Herpes (type 1 and 4) then a booster dose after two months. The third group was vaccinated with inactivated Equine Herpes (type 1 and 4) followed by two booster doses at two months intervals. Three horses were kept as a negative control in the fourth group. Serum samples were tested for the EHV and antibodies using virus Neutralization Test (VNT) and ELISA; it was found that VNT against EHV-1 indicated that the neutralizing antibody titer value ≥ 4 fold titer rise had been demonstrated at 28th-day post-vaccination for all vaccinated horse groups, it was demonstrated that the vaccinated horse group (1) indicated the significant greater titer values compared to other vaccinated groups and showed protective titer value till the end of the experiment (6 months post-vaccination), There is an agreement in titer values between ELISA and VNT tests for EHV was observed, but it could not reveal the same antibodies, where the ELISA measures antibodies against EHV1-4. It was concluded that the single-dose vaccination protocol was more appropriate for horse vaccination than other vaccination protocols.