Updates
Dated notes on developments in HSV vaccine research — trial registrations, results, and status changes. A trial starting is not evidence it will succeed; each update says only what its sources support.
- State of the evidence: October 2026
A plain-language look at where herpes vaccine research stands, as of 21 October 2026. No tracked trial changed status this month, the trial that is furthest along is still a small early safety study in people, and two university vaccines that have only been tested in mice were added to the tracker.
- New preclinical data extend the trivalent mRNA approach to HSV-1 eye disease
A peer-reviewed mouse study from the University of Pennsylvania group behind the trivalent gC2/gD2/gE2 mRNA design — the approach licensed to BioNTech as BNT163 — reported that the vaccine protected against HSV-1 eye infection and spread to the nervous system in mice. The findings are preclinical (in animals) and broaden the trivalent rationale beyond genital HSV-2; on their own they are not evidence of protection in people.
- Moderna ends its therapeutic HSV vaccine program (mRNA-1608)
Trade press reported on 20 November 2025 that Moderna will not advance mRNA-1608, its therapeutic HSV-2 vaccine candidate, to Phase 3, discontinuing the program as part of a company-wide pipeline cut. We have not yet confirmed this against a Moderna release or filing. Its Phase 1/2 trial had completed in April 2025 with encouraging interim data; the available reporting frames the decision as strategic rather than a reported safety or efficacy failure.
- IDWeek 2025: first clinical data for two mRNA HSV vaccine candidates
At IDWeek 2025 (19–22 October, Atlanta), interim clinical data were presented for two mRNA herpes vaccine candidates: BioNTech's prophylactic BNT163 (Phase 1) and Moderna's therapeutic mRNA-1608 (Phase 1/2). Both are early-stage safety and immune-response read-outs shared as conference abstracts — encouraging early signals, not evidence that either prevents or controls disease.