# An R2 non-neuroinvasive herpes simplex virus type 2 vaccine

> **NIH NIH R42** · THYREOS, INC · 2024 · $663,123

## Abstract

PROJECT SUMMARY
There is an unmet need for a herpes simplex virus (HSV) vaccine. We propose to
develop a live-attenuated HSV-2 vaccine based on our R2 technology platform. R2
vaccines show unprecedented safety and efficacy in animal models, and offer
antigenicity superior to subunit/mRNA and single-round vaccine designs. R2 vaccines
are also the first live-attenuated alphaherpesvirus vaccines that lack neuroinvasive
potential, and thereby are incapable of establishing life-long infections in the nervous
system. In phase I of this fast-track STTR application, we propose to: (i) produce a HSV-
2 self-excising infectious clone of a low-passage clinical isolate, (ii) use the clone to
produce a HSV-2 R2 recombinant, and (iii) characterize the R2 vaccine in culture side by
side with our existing HSV-1 R2 vaccine candidate. In phase II, the HSV-2 R2 vaccine
will be tested for safety, immunogenicity, and efficacy in mice and guinea pigs. This work
will provide the foundation to advance product development to clinical trials.

## Key facts

- **NIH application ID:** 11077588
- **Project number:** 4R42AI177202-02
- **Recipient organization:** THYREOS, INC
- **Principal Investigator:** Gregory Allan Smith
- **Activity code:** R42 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $663,123
- **Award type:** 4N
- **Project period:** 2024-06-01 → 2026-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11077588

## Citation

> US National Institutes of Health, RePORTER application 11077588, An R2 non-neuroinvasive herpes simplex virus type 2 vaccine (4R42AI177202-02). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/11077588. Licensed CC0.

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