# Efficacy of CMV vFcR vaccines to prevent congenital CMV transmission

> **NIH NIH P01** · WEILL MEDICAL COLL OF CORNELL UNIV · 2024 · $307,383

## Abstract

ABSTRACT – PROJECT 3
Congenital cytomegalovirus (cCMV) is the most common in utero infection, affecting approximately 1 in
every 200 newborns and causing devastating neurologic impairment in 1 in 5 infected infants. Placental
transmission of CMV is significantly reduced in women experiencing reinfection (3-4%) compared to
women experiencing CMV infection for the first time during pregnancy (30-40%), suggesting that
maternal CMV-specific adaptive immunity can protect against cCMV infection. However, to effectively
reduce cCMV prevalence, the protective effects of vaccine-elicited immunity must supersede that of
natural immunity. Several challenges have limited CMV vaccine development, including the numerous
immune evasion mechanisms of the virus. One of these mechanisms is viral Fc receptors (vFcȖRs) that
bind the Fc region of IgG, which our team showed in vitro to interfere with host Fc-mediated antibody
effector functions that we showed to be critical immune factors for preventing cCMV transmission. In
our model of primary CMV infection in pregnant rhesus macaques (RM), we identified three vFcȖRs
encoded by rhesus CMV (RhCMV). Utilizing an engineered vFcȖR-deleted RhCMV, we determined that
while the 'vFcȖR virus could reach a similar peak viremia as the parental full-length virus (FL-RhCMV),
it was cleared from the blood significantly earlier. Conversely, CD4+ T cell depletion of pregnant RM
dams and subsequent infection with 'vFcȖR restored viremia to FL-RhCMV levels. While this revealed
that placental transmission does not require the presence of vFcȖRs, it highlights their role in limiting
antibody effectiveness in vivo. Therefore, the goal of this project is to develop and test CMV vaccine
strategies that will interrupt the action of vFcȖRs in cCMV transmission in the RM model. We
hypothesize that addition of passive or active vaccination against RhCMV vFcȖRs to an entry
glycoprotein-based vaccine strategy will enhance plasma Fc receptor-mediated IgG functions and
protect against cCMV transmission in a nonhuman primate model. Specifically, we will define immunity
against vFcȖRs in natural immunity and after immunization (Aim 1), define the impact of passive
antibodies against vFcȖRs on the protective effect of pre-existing anti-RhCMV antibodies on cCMV
transmission (Aim 2), and determine the ability of inclusion of vFcȖR antigens with a viral entry
glycoprotein (gB) mRNA-LNP vaccine to enhance protection against cCMV in the RM model (Aim 3).
This preclinical assessment of a novel CMV vaccine strategy will inform and de-risk potential human
clinical trials seeking to reduce the most common infectious cause of birth defects and brain damage.

## Key facts

- **NIH application ID:** 10874240
- **Project number:** 2P01AI129859-07
- **Recipient organization:** WEILL MEDICAL COLL OF CORNELL UNIV
- **Principal Investigator:** Sallie R. Permar
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $307,383
- **Award type:** 2
- **Project period:** 2019-07-24 → 2029-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10874240

## Citation

> US National Institutes of Health, RePORTER application 10874240, Efficacy of CMV vFcR vaccines to prevent congenital CMV transmission (2P01AI129859-07). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10874240. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*