Comment: The quality of evidence is downgraded by study limitations (unclear risk of bias).
The recommendation is strong because shortening the duration symptoms, which may be severe, is important for a large majority of patients, and adverse effects are very uncommon. The cost of treatment is low.
A Cochrane review «Interventions for men and women with their first episode of genital herpes»1 «Heslop R, Roberts H, Flower D et al. Interventions...»1 included 26 studies with a total of 2084 men and women experiencing their first episode of genital herpes. Oral acyclovir, when compared to placebo, reduced the duration of symptoms (mean difference (MD) -3.22, 95% CI -5.91 to -0.54; 2 trials, I²=52%). Oral valacyclovir showed a similar length of symptom duration when compared to acyclovir in two studies. Two studies reported no evidence of a reduction in the number of median days to recurrence following treatment with oral acyclovir versus placebo.