Vaccination of foals with a modified live, equid herpesvirus-1 gM deletion mutant (RacH Delta gM) confers partial protection against infection

摘要

Equid herpesvirus-1 (EHV-1) causes respiratory and neurological disease and late gestation abortion in pregnant mares. Current vaccines contain either inactivated or live EHV-1, but fail to provide complete clinical or virological protection, namely prevention of nasopharyngeal shedding and cell-associated viraemia. Thus, the development of novel products, such as modified live virus (MLV) vaccines which stimulate virus-specific, humoral and cell mediated immune responses more effectively remains a priority. Two groups of weaned foals (n = 6 each group) were used in a longitudinal, prospective, experimental study to evaluate immune responses elicited by two vaccinations with a glycoprotein M (gM) deletion mutant of EHV-1 (RacHdeltagM). Following two concurrent intranasal and intramuscular inoculations six weeks apart, vaccinated (8.4 +/- 0.2 months old) and control foals (6.2 +/- 0.4 months) were challenge infected intranasally with EHV-1 Ab4/8 four weeks after the second vaccination and clinical signs and virological replication measured.