Untreated Recurrence Baseline
HSV-2 hides in sacral nerve ganglia and reactivates without treatment.
- 4–12: Median recurrences/yr (untreated adults)
- ~55: Days shedding/yr (asymptomatic + symptomatic)
- ~490M: Global HSV-2 prevalence (adults worldwide)
- ~10%: Partner risk/yr, no rx (discordant couples)
Latency in the ganglion
Virus persists dormant in sacral dorsal root ganglion neurons.
Latency allows lifelong intermittent reactivation.
Recurrence triggers
Stress, illness, and sun exposure can trigger reactivation flares.
Daily Suppressive Therapy Initiation
Daily valacyclovir or acyclovir begins blocking viral DNA replication.
- 500mg: Typical valacyclovir dose (once daily)
- ~1–2wk: Time to steady state (plasma levels)
- 3–5x: Bioavailability vs acyclovir (valacyclovir prodrug)
- >80%: Adherence needed (for full benefit)
Mechanism of action
Nucleoside analog halts viral DNA polymerase during replication.
Consistency matters more than dose size.
Onset of benefit
Suppressive effect builds gradually over the first months.
Reduced Outbreak Frequency
Sustained daily therapy cuts symptomatic recurrences substantially.
- ~70–80%: Recurrence reduction (vs untreated)
- Multiple: Trials showing benefit (RCT evidence base)
- Adherence: Effect scales with (+ duration)
- Low: Breakthrough risk (at high adherence)
Dose-response pattern
Higher adherence over more months yields fewer flares.
Missed doses let reactivation slip through.
Long-term suppression
Years of daily use remain safe and well tolerated.
Reduced Asymptomatic Shedding
Suppressive therapy also lowers silent viral shedding between outbreaks.
- ~80–90%: Shedding reduction (on daily therapy)
- Most days: Shedding without symptoms (untreated baseline)
- PCR swabs: Detection method (research studies)
- Transmission: Shedding drives (even without lesions)
Silent viral release
Virus sheds from skin even when no symptoms appear.
Shedding, not just outbreaks, spreads HSV-2.
Why it matters
Lower shedding directly lowers exposure to partners.
Lowered Partner Transmission Risk
Combined effects meaningfully cut annual risk to a partner.
- ~48–77%: Transmission risk cut (valacyclovir studies)
- Further drop: Add condoms (combined protection)
- Landmark RCT: Discordant couple studies (Corey et al. 2004)
- Never zero: Residual risk (counsel accordingly)
Risk reduction, not elimination
Suppression lowers but does not eliminate transmission risk.
Combine therapy with condoms and disclosure.
Shared decision-making
Couples weigh adherence, condoms, and disclosure together.