Some progress has been made in antiviral chemotherapeutic control of HSV primary infections with drugs such as acyclovir (Corey and Holmes, 1983; Gunby, 1983). However, such approaches do not prevent the virus from establishing latency, which would be the ultimate goal of vaccination. An immunization approach that could prevent both primary infections and recurrences would be the most desirable form of control. The feasibility of this is discussed under “Vaccine Preventable Illness.”

It should be stressed that HSV and other human herpes viruses, which rapidly become shielded from the immune response in the dorsal root ganglia, present a more difficult problem in vaccine development than other agents for which the target organ is distant to the portal of entry. To protect effectively against these viruses, the level of immunity resulting from vaccination must be very high. Achievement of these high levels of immunity probably will require that subunit glycoprotein vaccines be administered periodically. This may pose a problem of maintaining immunity in young adults, who probably have a low frequency of physician visits for other purposes.

Corey and Mertz (in press) have discussed the concepts and problems involved in developing vaccines against HSV.

Defining the target population is the first step in calculating the possible reduction in morbidity and mortality (or the maximum potential health benefit) that could be produced by a vaccine candidate. This knowledge can be translated into an estimate for vaccine preventable illness (VPI). For HSV, VPI is defined as the number of cases,