Caprine herpesvirus 1 vaccine adjuvanted with the LTK63 mutant as a mucosal adjuvant induces strong protection against genital infection in goats

Caprine herpesvirus 1 provides a unique virus-animal model to investigate potential tools applicable for the therapy and prophylaxis of genital herpesvirus infections of humans. In order to evaluate the efficacy of mucosal immunization in the goat model, an inactivated CpHV-1 vaccine was adjuvated with the enzymatically inactive mutant of the heat-labile enterotoxin of Escherichia coli, LTK63, and used to immunize goats by the vaginal route, by administering two doses at a 3-week interval. The mucosal vaccine was safe, as neither local nor systemic reactions were associated with the vaccine administration. The vaccinated animals displayed high levels of secretory IgA and were significantly protected after challenge with the virulent CpHV-1 strain, with marked decrease in virus shedding, while the unvaccinated goats were not. These findings suggest that mucosal immunization is potentially exploitable in the control of genital infection by herpesviruses.