Prevention of herpes genitalis by the 'Bulgarian' vaccine F.HSV-2V(PRK): preliminary clinical evidence.

AIM

To examine the antigenic properties of the formalin-inactivated herpes simplex virus type 2 (HSV-2) virus-particle vaccine F. HSV-2V(PRK), which has been used therapeutically in Bulgaria for 30 years, and to make preliminary assessment of its potential protective efficacy by a follow-up of vaccinated patients with herpes genitalis.

METHODS

Properties of the vaccine were examined by standard immunological laboratory tests. Fifty-five patients at risk of herpes genitalis received 2-4 vaccinations and were monitored during a 6-year follow-up.

RESULTS

The vaccine was antigenic in laboratory tests and absorbed neutralizing antibody from hyperimmune rabbit serum against herpes simplex virus type 1 (HSV-1). In vaccinated patients, there was an overall contraction rate of herpes genitalis of 5.4%. There was no evidence of significant local or generalized adverse effects from vaccination.

CONCLUSION

Bulgarian vaccine F.HSV-2V(PRK) may have protective efficacy, which, in association with its apparent safety from our findings and from its clinical use for over 30 years in Bulgaria, suggests that it should be scrutinized by a formal clinical trial.