Year of publication | 1997 | 1999 | 1992 | 2001 |
Setting | Two antenatal clinics (University Hospital Seattle and Madigan Army Hospital, Tacoma) | Two multicentre randomised controlled trials of an ineffective HSV-2 vaccine | Two university research clinics | Multicentre randomised controlled trials of an ineffective HSV-2 vaccine |
Participants | 7046 pregnant women at risk for HSV acquisition | 2393 sexually active adults at high risk of HSV-2 acquisition | 144 heterosexual couples discordant for genital HSV infection (97% had HSV-2) | 528 monogamous couples discordant for HSV-2 infection |
Duration of follow up | Duration of pregnancy | 18 months | Median 334 days | 18 months |
Outcome measure(s) | Type specific seroconversion | Culture proven HSV infection or type specific seroconversion in susceptible partner | Culture proven HSV infection or type specific seroconversion in susceptible partner | Acquisition of HSV-2 infection by susceptible partner |
Transmisson rate | HSV-1 : 2.3 % (± SE 0.4) | HSV-1 : 1.0/100 person years | 16.9% | 9.7% |
(Male to female) | HSV-2 : 1.6% (± SE 0.4) | HSV-2 : 6.8/100 person years | | |
Transmisson rate | | HSV-1 : 1.9/100 person years | 3.8% | 1.9% |
(Female to male) | | HSV-2 : 4.4/100 person years | | |
Effect of pre-existing HSV-1 antibodies on risk of acquisition | No protective effect demonstrated | No protective effect demonstrated | Protective for female susceptible partners only | No protective effect demonstrated |
Effect of pre-existing HSV-1 antibodies on risk of transmission | – | – | No effect demonstrated | Increased risk of transmission in HSV-1 and HSV-2 coinfected source partners |
Effect of condoms on risk of transmission | – | – | No effect demonstrated | Use in >25% of sex acts protective for female susceptible partners |
Other determinants of transmission | – | – | – | Age, frequency of sexual activity, duration of relationship |