# mVACS--mRNA Vaccines for C. difficile Suppression

> **NIH NIH U19** · UNIVERSITY OF PENNSYLVANIA · 2024 · $1,529,954

## Abstract

SUMMARY – mVACS PROGRAM
Clostridioides difficile is the most reported nosocomial pathogen in the United States and a major public health
threat worldwide. Challenges in treating infections with conventional antibiotics and increasing rates of recurrent
infection underscore the need for new interventions. To date, no vaccine has proven to be effective at clearing
C. difficile from infected individuals. The mVACS program—"mRNA Vaccines for C. difficile Suppression”—is
tightly focused on the goal of designing and implementing improved vaccines to mitigate or eliminate C. difficile
infection (CDI). For this we will employ modified mRNA vaccine technology, which has been pioneered so
successfully by team member Dr. Drew Weissman and his collaborators at BioNTech to immunize against SARS-
CoV-2. Already Drs. Weissman, Alameh, and Zackular have established a collaboration with BioNTech to
develop an mRNA targeting C. difficile toxins and other antigens and shown their lead formulation to be highly
protective in mice challenged with a lethal dose of C. difficile. However, C. difficile is not fully cleared from the
mice, and there is mild transient pathogenesis, so there is more to be done. The team is moving forward with
this anti-toxin vaccine, but improvements in design are necessary for optimal efficacy. The mVACS team is a
highly skilled and synergistic group dedicated to developing modified mRNAs to oppose C. difficile infection and
pathogenesis. The program consists of three projects and three cores. Project 1 (Vaccine Development)
(Project Leads: Alameh and Weissman) will test new mRNAs against multiple C. difficile targets, as well as
mixtures of mRNAs and novel nanoparticle/lipid formulations. Project 2 (Antigen Discovery) (Project Lead:
Zackular) will take advantage of advanced analysis of C. difficile microbiology and ecology of infection to produce
a series of novel vaccine targets. Project 3 (Immunology) (Project Lead: Abt) will quantify mucosal adaptive
immune responses against C. difficile in humans and mouse systems, identifying gaps and correlates of efficacy.
Projects 2 (Antigen Discovery) and Project 3 (Immunology) will flow new data to Project 1 (Vaccine
Development) to optimize vaccine design. The Projects will be complemented by three Cores: Core A
(Administrative Core) (Core Leads: Bushman and Weissman), Core B (Genomics Core) (Core Leads:
Bittinger, Bushman, and Moustafa) and Core C (Clinical Core) (Core Leads: Kelly and Conrad). Together with
our industry partner BioNTech, we are highly optimistic that we can advance effective new vaccine designs to
suppress C. difficile.

## Key facts

- **NIH application ID:** 10792885
- **Project number:** 5U19AI174998-02
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Frederic D Bushman
- **Activity code:** U19 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $1,529,954
- **Award type:** 5
- **Project period:** 2023-03-01 → 2028-02-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10792885

## Citation

> US National Institutes of Health, RePORTER application 10792885, mVACS--mRNA Vaccines for C. difficile Suppression (5U19AI174998-02). Retrieved via AI Analytics 2026-06-13 from https://api.ai-analytics.org/grant/nih/10792885. Licensed CC0.

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