Co-infection and Cancer (R21 Clinical Trial Not Allowed) | PAR 25 083

Opportunity Information: Apply for PAR 25 083

The National Institutes of Health (NIH) is offering the Co-infection and Cancer (R21 Clinical Trial Not Allowed) funding opportunity (PAR-25-083) to stimulate early-stage, exploratory research that clarifies how co-infections contribute to cancer. The central goal is to strengthen both mechanistic and epidemiologic studies that can uncover currently unestablished biological or population-level pathways linking multiple infections to carcinogenesis. By improving understanding of how two or more infectious agents interact in the body or within communities, the program aims to generate insights that could ultimately inform better prevention strategies, risk reduction approaches, and treatment ideas for cancers with infectious origins.

In this announcement, co-infection is broadly defined as infection by two or more agents occurring at the same time or in sequence, and it explicitly includes acute or chronic infections. The scope is not limited to viruses; it also encompasses bacteria, parasites, and other microorganisms, whether they are considered pathogenic or typically non-pathogenic. That broad definition is important because cancer risk may be shaped not only by a single well-known oncogenic agent, but also by how that agent behaves in the presence of additional microbes that alter inflammation, immune surveillance, tissue damage and repair, microbiome composition, or persistence of infection over time.

The FOA places special emphasis on studies involving co-infections that include known oncogenic agents, while specifically excluding HIV as the oncogenic co-infection focus. In other words, applicants are encouraged to examine combinations where at least one infection is already recognized as cancer-related (for example, established oncogenic viruses or other carcinogenic pathogens), but the combined effects with other infections are not yet well understood. The announcement also signals a preference for projects where studying co-infection could open new doors for prevention or treatment, such as identifying modifiable co-factors, clarifying who is at highest risk, uncovering synergistic mechanisms that can be targeted, or revealing intervention points like vaccination, antimicrobial treatment, screening strategies, or immune-based approaches that could reduce infection-driven cancer burden.

This opportunity uses the NIH R21 mechanism, which is typically intended for exploratory and developmental work that can be higher-risk or more novel, aimed at producing foundational findings, strong preliminary evidence, or proof-of-concept results that justify a later, larger study. The listing is explicitly "Clinical Trial Not Allowed," meaning the funded work should not involve prospective assignment of human participants to interventions to assess health-related outcomes. However, the topic area includes epidemiologic research, so well-designed observational studies, analyses of existing cohorts, biospecimen-based investigations, and other non-trial human research approaches may be appropriate as long as they stay within NIH definitions that do not constitute a clinical trial.

Eligibility is broad and includes many types of U.S.-based and non-U.S. organizations. Eligible applicants listed include state, county, city or township governments; special district governments; independent school districts; public and state-controlled institutions of higher education; private institutions of higher education; federally recognized Native American tribal governments; Native American tribal organizations other than federally recognized governments; public housing authorities/Indian housing authorities; nonprofits with or without 501(c)(3) status (other than institutions of higher education); for-profit organizations other than small businesses; small businesses; and other entities. The announcement also highlights additional eligible applicant categories such as 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), faith-based or community-based organizations, U.S. territories or possessions, eligible federal agencies, regional organizations, and foreign (non-U.S.) entities. This wide eligibility aligns with the global and community-specific nature of infection-related cancers and the fact that co-infection patterns can differ substantially by geography, health systems, and population characteristics.

Administratively, the opportunity is a discretionary NIH grant in the Education and Health activity category and is associated with CFDA number 93.399. The posting shows a creation date of November 21, 2024, and an original closing date of January 7, 2026. The award ceiling and expected number of awards are not specified in the provided source details, which often indicates applicants should rely on the full FOA text and NIH standard R21 guidance for budget and scope expectations.

Overall, this FOA is designed for investigators who want to ask focused, innovative questions about how multiple infections jointly influence cancer development, progression, or risk markers, and who can propose feasible, non-clinical-trial studies that generate actionable knowledge. Projects that connect co-infection biology or epidemiology to clear prevention or treatment opportunities, especially when an established oncogenic agent is part of the co-infection scenario (excluding HIV), appear to be particularly well aligned with NIH's stated preferences for this call.

• 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): 93.399.
• This funding opportunity was created on 2024-11-21.
• Applicants must submit their applications by 2026-01-07. (Agency may still review applications by suitable applicants for the remaining/unused allocated funding in 2026.)
• 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 25 083

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