# Optimal adjuvant/antigen formulation toward a Staphylococcus aureus human vaccine

> **NIH NIH R41** · IMMUNARTES LLC · 2022 · $253,925

## Abstract

Project Summary / abstract:
Staphylococcus aureus is a commensal of the human skin and an invasive pathogen, as well as the leading
cause of skin and soft tissue infections (SSTI) or sepsis in the United States. S. aureus has developed
resistance against all known antibiotics. S. aureus infection is not associated with the development of immunity
and, even with surgical and antibiotic therapy, recurrent infections occur in up to 30% of patients. Therefore,
the development of a vaccine or immune therapeutic that prevents S. aureus SSTI, bacteremia, sepsis, or that
improves the outcome of standard-of-care therapies, or that reduces the incidence of recurrent infections is of
high importance. The immune evasive properties of S. aureus are primarily mediated by staphylococcal protein
A (SpA), a surface protein that binds immunoglobulin (Ig) thereby preventing opsonophagocytic killing (OPK)
by immune cells and suppression of host adaptive immune responses. Our lead vaccine is SpA*, a fully
detoxified fragment of SpA which when adjuvanted with aluminum hydroxide (Alum) elicits immune responses
that can prevent and reduce nasopharyngeal colonization of S. aureus and invasive S. aureus diseases. Alum
drives primarily TH2-effector responses and is included in many FDA approved vaccines but several studies
have suggested that stimulating a broad TH1 / TH17 immune response may be required for vaccine protection
against the wide range of diseases caused by S. aureus. Therefore, the goal of this phase I proposal is the
development of clinical adjuvant formulations that broadly stimulate SpA-specific humoral and cellular immune
responses in animals. In specific aim 1 we will establish a clinical adjuvant that stimulates effective TH1 / TH17
cellular and TH2 humoral immune responses against SpA* antigen in mice, rabbits, and guinea pigs. Specific
aim 2 will characterize the quality of the humoral vaccine responses generated against adjuvanted SpA* in
sera from vaccinated animals by developing assays that measure SpA-neutralizing activity and ability to
promote OPK of S. aureus. These studies are critical for determining the value of SpA-specific antibody titers
required in vaccinated subjects to promote OPK of S. aureus and neutralization of SpA's Ig-binding activity.
Phase II studies will be designed to cGMP manufacture the vaccine and demonstrate protective efficacy of the
lead vaccine formulation in guinea pig and rabbit models of MRSA diseases in support of clinical testing.

## Key facts

- **NIH application ID:** 10383513
- **Project number:** 1R41AI167268-01
- **Recipient organization:** IMMUNARTES LLC
- **Principal Investigator:** Dominique Missiakas
- **Activity code:** R41 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $253,925
- **Award type:** 1
- **Project period:** 2022-01-04 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10383513

## Citation

> US National Institutes of Health, RePORTER application 10383513, Optimal adjuvant/antigen formulation toward a Staphylococcus aureus human vaccine (1R41AI167268-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10383513. Licensed CC0.

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