BNT163
phase 1 BioNTech SE
Last updated:
| Developer | BioNTech SE |
|---|---|
| Platform | mRNA |
| HSV target | HSV-2 |
| Approach | prophylactic |
| Phase | phase 1 |
| Status | First-in-human Phase 1 trial ongoing (active, not recruiting). Started December 2022; estimated primary completion October 2026. No efficacy data published. |
| Trials | NCT05432583 |
BioNTech's mRNA prophylactic (preventive) vaccine candidate aimed at preventing genital lesions caused by HSV-2, and potentially HSV-1. Its first-in-human Phase 1 trial began in December 2022 and is ongoing but no longer recruiting, with estimated primary completion in October 2026. As of mid-2026 it is an early-stage safety and immune-response study; no efficacy results have been published.
What it is
BNT163 is BioNTech’s prophylactic herpes vaccine candidate — one designed to prevent infection rather than treat an existing one. Its stated goal is to prevent the genital lesions caused by HSV-2, and potentially HSV-1.
It is an mRNA vaccine: it delivers genetic instructions that prompt the body’s cells to make selected viral proteins so the immune system learns to recognize them. It is a trivalent vaccine, encoding three HSV-2 glycoproteins (gC2, gD2, and gE2), with the aim of blocking the virus from entering and spreading between cells and of countering some of the ways the virus evades immune responses. BNT163 is the clinical form of the trivalent mRNA approach developed at the University of Pennsylvania and licensed to BioNTech — see Trivalent gC2/gD2/gE2 mRNA (UPenn) for the underlying preclinical science.
Where it stands
BNT163 is in a first-in-human Phase 1 trial (NCT05432583), a dose-escalation study evaluating safety, tolerability, and immune responses (including neutralizing antibodies) in healthy adults aged 18–55. The trial began in December 2022. Its status on ClinicalTrials.gov is Active, not recruiting, with estimated primary completion in October 2026.
A Phase 1 study of this kind is designed to answer whether the vaccine is safe and whether it triggers an immune response — not whether it prevents herpes. No efficacy data have been published. As of the date above, this is the only HSV vaccine from a large biopharmaceutical company still in active clinical development.
Registry snapshot
- Registry status
- Active, not recruiting
- Phase
- phase 1
- Enrollment
- 318 (actual)
- Lead sponsor
- BioNTech SE
- Started
- Dec 8, 2022
- Primary completion
- Oct 2026
Registry record last updated Oct 20, 2025.
Background
- How mRNA herpes vaccines work
Several of the most-watched herpes vaccine candidates use mRNA — the same technology behind the COVID-19 vaccines. This explainer covers how an mRNA vaccine delivers instructions for a cell to make selected viral proteins, why several HSV programs chose the approach, and why a platform that works for one disease is not proof it will work for another.
- HSV-1 vs HSV-2: what's the difference?
Herpes simplex virus comes in two types. HSV-1 has traditionally caused oral herpes and HSV-2 genital herpes, but that line has blurred, and either type can infect either site. The distinction still matters for vaccines: a vaccine can protect against one type and not the other, as the Phase 3 Herpevac trial showed. Neither type has an approved vaccine as of 2026.
- Prophylactic vs therapeutic: two very different herpes vaccines
"A herpes vaccine" can mean two different things. A prophylactic (preventive) vaccine is given to people who are not infected, to stop them getting herpes simplex virus (HSV) at all. A therapeutic vaccine is given to people who are already infected, to reduce outbreaks and viral shedding. The two use different trials, endpoints, and populations — so the first question to ask of any candidate is which goal it targets. Neither type is approved.
- What each clinical trial phase does and doesn't prove
A plain-language guide to reading herpes (HSV) vaccine news by trial phase. Each phase answers a different question, and early-phase results say nothing about whether a vaccine prevents disease. A trial existing or finishing is not the same as a vaccine working — the Phase 3 Herpevac trial ran to completion but missed its main goal, and as of 2026 no HSV vaccine has cleared Phase 3 to approval.
- Why gC2, gD2, and gE2? The trivalent vaccine rationale
Several leading HSV-2 vaccine candidates combine three viral surface proteins — gC2, gD2, and gE2 — to do two jobs at once: block the virus from entering cells and disable two of the tricks it uses to evade the immune system. The rationale is well supported by animal data; whether it protects people is still being tested in an early-stage (Phase 1) human trial of the candidate BNT163.
- Why is HSV so hard to vaccinate against?
Herpes simplex virus establishes a lifelong dormant infection in nerve cells and carries genes that actively blunt the immune response, so even natural infection does not stop reinfection or recurrences — a vaccine has to outperform what the body manages on its own. This explainer walks through the four obstacles researchers keep hitting: latency, active immune evasion, unknown correlates of protection, and animal models that do not fully mirror human disease. As of 2026, no HSV vaccine is approved.
Key literature
Sources
- A Clinical Trial to Study the Safety, Tolerability, and Immune Responses After Vaccination With an Investigational Vaccine Designed to Prevent Genital Herpes Lesions (NCT05432583)
- BioNTech Starts Phase 1 Clinical Trial for Prophylactic Herpes Simplex Virus-2 Vaccine Candidate BNT163
- Safety and Immunogenicity of BNT163, a Trivalent mRNA HSV Vaccine Candidate for Genital Herpes (abstract P-105)