Recent serosurveys indicate that the prevalence of genital herpes has continued to increase even during the decade of HIV. Much of this continued transmission is due to the difficulty of identifying the subclinical carrier of HSV-2. The development of serologic assays that accurately distinguish HSV-1 from HSV-2 infection now allow such persons to be identified, and recent studies indicate almost all HSV-2 seropositives have symptoms and signs of reactivation HSV-2. Moreover, over 50% will shed virus subclinically in the genital tract. This underestimation of this reactivation rate appears to be another factor in the continued spread of the virus throughout the population. The development of an HSV vaccine is imperative if we are to control this rapidly increasing infection.