Recombinant glycoprotein vaccine for the prevention of genital HSV-2 infection: two randomized controlled trials. Chiron HSV Vaccine Study Group

JAMA. 1999 Jul 28;282(4):331-40. doi: 10.1001/jama.282.4.331.


Context: In the last 3 decades, herpes simplex virus type 2 (HSV-2) infection seroprevalence and neonatal herpes have increased substantially. An effective vaccine for the prevention of genital herpes could help control this epidemic.

Objective: To evaluate the efficacy of a vaccine for prevention of HSV-2 infection.

Design: Two randomized, double-blind, placebo-controlled multicenter trials of a recombinant subunit vaccine containing 30 microg each of 2 major HSV-2 surface glycoproteins (gB2 and gD2) against which neutralizing antibodies are directed, administered at months 0, 1, and 6. Control subjects were given a citrate buffer vehicle. Participants were followed up for 1 year after the third immunization.

Setting and participants: We enrolled 2393 persons from December 10, 1993, to April 4, 1995, who were HSV-2 and human immunodeficiency virus seronegative. One trial with 18 centers enrolled 531 HSV-2-seronegative partners of HSV-2-infected persons; the other, with 22 centers, enrolled 1862 persons attending sexually transmitted disease clinics. A total of 2268 (94.8%) met inclusion criteria and were included in the analysis with 1135 randomized to placebo and 2012 to vaccine.

Main outcome measure: Time to acquisition of HSV-2 infection, defined by seroconversion or isolation of HSV-2 in culture during the study period by randomization group.

Results: Time-to-event curves indicated a 50% lower acquisition rate among vaccine vs placebo recipients during the initial 5 months of the trial; however, overall vaccine efficacy was 9% (95% confidence interval, -29% to 36%). Acquisition rates of HSV-2 were 4.6 and 4.2 per 100 patient-years in the placebo and vaccine recipients, respectively (P =.58). Follow-up of vaccine recipients acquiring HSV-2 infection showed vaccination had no significant influence on duration of clinical first genital HSV-2 episodes (vaccine, median of 7.1 days; placebo, 6.5 days; P>.10) or subsequent frequency of reactivation (median monthly recurrence rate with vaccine, 0.2; with placebo, 0.3; P>.10). The vaccine induced high levels of HSV-2-specific neutralizing antibodies in vaccinated persons who did and did not develop genital herpes.

Conclusions: Efficient and sustained protection from sexual acquisition of HSV-2 infection will require more than high titers of specific neutralizing antibodies. Protection against sexually transmitted viruses involving exposure over a prolonged period will require a higher degree of vaccine efficacy than that achieved in this study.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antibodies, Viral / biosynthesis
  • Case-Control Studies
  • Double-Blind Method
  • Female
  • Herpes Genitalis / immunology
  • Herpes Genitalis / prevention & control*
  • Herpesvirus 2, Human / immunology*
  • Humans
  • Male
  • Middle Aged
  • Neutralization Tests
  • Proportional Hazards Models
  • Vaccination
  • Vaccines, Synthetic* / administration & dosage
  • Vaccines, Synthetic* / immunology
  • Viral Envelope Proteins / immunology*
  • Viral Vaccines* / administration & dosage
  • Viral Vaccines* / immunology


  • Antibodies, Viral
  • Vaccines, Synthetic
  • Viral Envelope Proteins
  • Viral Vaccines
  • glycoprotein B, herpes simplex virus type 2
  • glycoprotein D-herpes simplex virus type 2