Vaccination strategies to prevent genital herpes and neonatal herpes simplex virus (HSV) disease

Vaccination strategies to prevent genital and neonatal herpes simplex virus (HSV) disease have a history of apparent efficacy in animal studies followed by failure in clinical trials. Further study of the immune response induced by natural HSV infections in both adults and neonates will provide insight into the requirements for vaccination against acute disease and recurrences. Lessons can also be learnt from the recent partial success of a HSV-2 glycoprotein D vaccine coupled with monophosphoryl lipid A adjuvant, which induced protection from clinical disease in HSV-1 and HSV-2 seronegative women. Its efficacy has been attributed to enhancement of Th-1 immunity by the adjuvant. Newer vaccine vectors including DNA vaccines, recombinant viral vaccines and specific HSV mutants are being developed but better animal models are required for more rapid progress. This review examines the history of HSV vaccine development, describes recent progress towards an effective prophylactic vaccine against HSV and outlines further improvements required to make current vaccines immunogenic to a wide population.