# Investigation of novel chlamydia vaccines in male infection models and sexual transmission challenges

> **NIH NIH F31** · UNIVERSITY OF NEW MEXICO HEALTH SCIS CTR · 2024 · $36,022

## Abstract

PROJECT SUMMARY
Chlamydia trachomatis (Ct) is the pathogen that causes the world’s most common bacterial sexually transmitted
infection, with over 129 million cases in 2020. Untreated urogenital Ct can have severe sequelae, including
pelvic inflammatory disease, ectopic pregnancy, tubal factor infertility, epididymitis, urethritis, and prostatitis.
Untreated anorectal Ct can lead to proctitis, ulcerations, abscesses, fissures, and fistulas. Anorectal infections
likely also act as a reservoir for the bacterium, in which urogenital infection occurs via autoinoculation. Most Ct
research has focused on female urogenital infections, as these infections more commonly cause severe
sequelae. However, there is a large gap and an urgent need to study Ct infections in males. Although male
urogenital tract infections are less likely to lead to severe sequelae, males can transmit infection to the female
reproductive tract, which is more vulnerable to complications. Additionally, anorectal infections occur in men
who have sex with men, men who have sex with women and in women. Current treatment is curative antibiotics,
but these do not prevent reinfection, do not robustly clear infection at all anatomic sites, and can have poor
patient compliance. Identifying strategies to reduce and prevent transmission of Ct, as well as limit infection, is
very urgent. Our lab has developed vaccines against Chlamydia using highly immunogenic bacteriophage virus-
like particles (VLPs) as a platform displaying short peptide epitopes of Ct adhesion factors in an immunogenic
manner. In particular, our Qb-VD4-MOMP vaccine, targeting Ct adhesion factor Major Outer Membrane Protein,
provides protection in female mice. However, the anorectal tract and male urogenital tract have distinct
immunological environments, and Ct infections at these sites are not well studied. This F31 proposal aims to
investigate the ability of our Qb-VD4-MOMP vaccine to protect against Chlamydia infection in male mice. The
overall goal of this proposed research is to determine the immunogenicity and protective ability of these vaccines
in male mice, utilizing urogenital, anorectal, and sexual transmission infection models. The outcome of this
research will highlight the populations that will benefit from vaccination by preventing both infection and
transmission. Aim 1 will investigate vaccine efficacy in male mice urogenitally or anorectally infected with
Chlamydia. Additionally, vaccine efficacy in the context of immunization of either or both partners will be
investigated in mouse sexual transmission models of Chlamydia (Aim 2). These vaccines may or may not elicit
the same protection in males as in females, and the use of adjuvants, mixed vaccines, or alternative vaccine
targets may be necessary to provide protection in males. Overall, this research will reveal important aspects of
vaccine-mediated protection and advance these vaccines closer to human clinical trials.

## Key facts

- **NIH application ID:** 11000254
- **Project number:** 5F31AI179064-02
- **Recipient organization:** UNIVERSITY OF NEW MEXICO HEALTH SCIS CTR
- **Principal Investigator:** Andzoa Jamus
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $36,022
- **Award type:** 5
- **Project period:** 2023-09-01 → 2025-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11000254

## Citation

> US National Institutes of Health, RePORTER application 11000254, Investigation of novel chlamydia vaccines in male infection models and sexual transmission challenges (5F31AI179064-02). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/11000254. Licensed CC0.

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