Co-infection and Cancer (R21 Clinical Trial Not Allowed) | PAR 23 056

Opportunity Information: Apply for PAR 23 056

The National Institutes of Health (NIH) is offering the Co-infection and Cancer (R21 Clinical Trial Not Allowed) grant opportunity (Funding Opportunity Number PAR 23-056) to support early-stage, exploratory research that clarifies how co-infections influence cancer risk and cancer-related biological processes. The core aim is to strengthen both mechanistic studies (how co-infections change cellular, immune, microbial, or tissue-level pathways) and epidemiologic studies (how patterns of multiple infections relate to cancer occurrence in populations) in order to uncover carcinogenic pathways that are not yet well established. The expectation is that new insights from these projects will point toward practical prevention or treatment strategies for cancers that are linked to infections.

In this announcement, "co-infection" is defined broadly as infection by two or more infectious agents, whether they occur at the same time or one after another. The FOA explicitly includes acute and chronic infections and allows for a wide range of microorganisms, including viruses, bacteria, parasites, and other microbes. Importantly, the scientific emphasis is on the interplay between infections: how one pathogen may alter host immunity or tissue environments in ways that change susceptibility to another pathogen, how combined infections might increase or reduce cancer risk relative to single infections, and how sequential exposures might create long-term biological conditions that contribute to malignant transformation.

NIH indicates a preference for studies that examine co-infections involving known oncogenic agents, while specifically excluding human immunodeficiency virus (HIV) as the oncogenic co-infection focus. In practice, this means applications are especially responsive when they build on established infection-cancer links (for example, well-known oncogenic viruses or bacteria) and then investigate what changes when an additional infectious agent is present. The FOA also highlights interest in co-infection scenarios that create "novel opportunities" for prevention and treatment, which can include identifying modifiable co-factors, suggesting vaccine or antimicrobial intervention points, clarifying who is at highest risk, or revealing mechanisms that could be targeted therapeutically.

The mechanism is an R21, which generally aligns with exploratory, hypothesis-generating work, feasibility studies, and innovative approaches that may be too early for larger, longer R01-style projects. Consistent with the title, clinical trials are not allowed under this FOA, so proposed work should be non-trial research (for example, observational human studies, analyses of existing cohorts and biospecimens, laboratory mechanistic experiments, computational or statistical modeling, and other non-interventional designs). The opportunity sits within NIH's health-related research mission and is listed under Assistance Listing (CFDA) number 93.393, with activity categories noted as Education and Health.

A wide range of applicants are eligible. In addition to typical U.S. research applicants such as public and private institutions of higher education, nonprofit organizations (both 501(c)(3) and non-501(c)(3)), for-profit organizations (other than small businesses), small businesses, and various levels of government (state, county, city/township, special districts), the FOA explicitly includes many mission-relevant or underserved-community-focused institutions and entities. These include Alaska Native and Native Hawaiian Serving Institutions, Asian American Native American Pacific Islander Serving Institutions (AANAPISI), Hispanic-serving Institutions, Historically Black Colleges and Universities (HBCUs), Tribally Controlled Colleges and Universities (TCCUs), federally recognized tribal governments, and Indian/Native American tribal governments that are not federally recognized. Faith-based and community-based organizations, eligible federal agencies, U.S. territories or possessions, and non-U.S. (foreign) organizations and regional organizations are also listed as eligible, reflecting NIH's interest in supporting research that may require diverse populations, international settings, or region-specific infection burdens.

Key administrative details provided include an original closing date of 2025-11-16, a stated award ceiling of $275,000, the opportunity category listed as discretionary, and the funding instrument type listed as a grant. The opportunity was created on 2022-12-14. While the number of expected awards is not specified in the provided data, applicants should plan proposals around the R21's exploratory scope and the stated budget ceiling, emphasizing clear innovation, strong rationale for why co-infection is central to the cancer-related question, and a credible path to generating results that can later support more definitive studies or translational prevention strategies.

• The National Institutes of Health in the education, health sector is offering a public funding opportunity titled "Co-infection and Cancer (R21 Clinical Trial Not Allowed)" and is now available to receive applicants.
• Interested and eligible applicants and submit their applications by referencing the CFDA number(s): 93.393.
• This funding opportunity was created on 2022-12-14.
• Applicants must submit their applications by 2025-11-16. (Agency may still review applications by suitable applicants for the remaining/unused allocated funding in 2026.)
• Each selected applicant is eligible to receive up to $275,000.00 in funding.
• Eligible applicants include: State governments, County governments, City or township governments, Special district governments, Independent school districts, Public and State controlled institutions of higher education, Native American tribal governments (Federally recognized), Public housing authorities/Indian housing authorities, Native American tribal organizations (other than Federally recognized tribal governments), Nonprofits having a 501 (c) (3) status with the IRS, other than institutions of higher education, Nonprofits that do not have a 501 (c) (3) status with the IRS, other than institutions of higher education, Private institutions of higher education, For-profit organizations other than small businesses, Small businesses, Others.

Apply for PAR 23 056

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