# A Novel Sublingual Vaccine to Prevent Neisseria Gonorrhoeae Infection

> **NIH NIH R43** · VIRTICI, LLC · 2024 · $306,500

## Abstract

Project Summary
Our goal is to advance a novel, safe and effective sublingual (SL) vaccine against Neisseria gonorrhoeae (Ng)
infection.
Antibiotic resistant Ng is an interconnected global threat to people, animals, and the environment. Furthermore,
approximately 50% of all annual Ng infections in the US are drug-resistant1. The emergence of drug-resistant
Ng is accelerating, and previous antibiotic treatments such as penicillin, tetracycline, ciprofloxacin, and
cefixime are no longer recommended1, 2. A single recommended treatment remains – ceftriaxone. Current
research suggests that it is the suppression of Th1 and Th2 responses by Ng, modulated by increased Th17
responses, which drives Ng infection and re-infection3-5. Protection from Ng is thought to benefit from a robust
Th1 response or balanced Th1/Th2 response3, 6, 7. However, current Ng vaccination approaches mainly using
aluminum salt do not induce appropriate Th1/2 responses, limiting vaccine efficacy4, 8, 9. A vaccine that
generates a strong Th1, or a more balanced Th1/Th2 response, with robust mucosal immunity, would
significantly enhance Ng vaccine efficacy.
Current Ng vaccine approaches are mainly focused on developing novel parenteral vaccines4, 8. Parenteral
vaccines are generally effective at stimulating systemic antibody-mediated immune responses but are less
effective at inducing mucosal immunity10-12. Parenteral vaccines require significant resources for cold-chain
management and administration, which translate into slow global vaccination. Since low- and middle-income
countries have the highest Ng burden, new vaccines must support global delivery.
Our project team brings together three innovative aspects and areas of expertise that will make a novel SL Ng
vaccine a reality. First, we have identified novel Ng antigens expressed during natural mucosal infection that
generate cross-reactive antibody responses. Second, our novel TLR4 agonist, INI-2005, induces robust
systemic and mucosal immune response following SL administration. Third, INI-2005 demonstrates good
synthesis and thermostability properties and appears safe.
Building from this work, this application is designed to validate a SL Ng vaccine consisting of a novel SL
adjuvant, INI-2005, and three unique Ng antigens identified from a reverse vaccinology-like approach. The
specific aims of this Phase I SBIR application are to: 1) Produce and benchmark the TLR agonist and Ng
antigens; 2) Determine the optimal SL formulation to maximize immune responses in mice; and 3)
Demonstrate that the SL formulation effectively protects mice against Ng infection. Funding of this application
will validate a SL vaccine to prevent Ng infection, designed for robust Th1 immune responses and mucosal
immunity, administered easily, and thermostable for rapid, global distribution.

## Key facts

- **NIH application ID:** 10830447
- **Project number:** 5R43AI174574-02
- **Recipient organization:** VIRTICI, LLC
- **Principal Investigator:** Neil A Fanger
- **Activity code:** R43 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $306,500
- **Award type:** 5
- **Project period:** 2023-04-20 → 2026-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10830447

## Citation

> US National Institutes of Health, RePORTER application 10830447, A Novel Sublingual Vaccine to Prevent Neisseria Gonorrhoeae Infection (5R43AI174574-02). Retrieved via AI Analytics 2026-06-12 from https://api.ai-analytics.org/grant/nih/10830447. Licensed CC0.

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