Research Towards Developing a Cure for HBV in HIV/HBV Co-Infection (R21 Clinical Trial Not Allowed) | PAS 20 121

Opportunity Information: Apply for PAS 20 121

The National Institutes of Health (NIH) funding opportunity titled "Research Towards Developing a Cure for HBV in HIV/HBV Co-Infection (R21 Clinical Trial Not Allowed)" (Funding Opportunity Number PAS-20-121) is a discretionary grant program designed to support early-stage, high-impact research that could move the field closer to a functional or complete cure for hepatitis B virus (HBV) in people who are also living with human immunodeficiency virus (HIV). The central focus is the scientific and clinical reality that HBV cure is more complicated in the setting of HIV co-infection, and that solving those added challenges will likely require innovative approaches spanning basic discovery, translational work, and certain types of clinical research that do not meet the definition of a clinical trial under NIH rules for this announcement.

This FOA uses the NIH R21 mechanism, which is typically intended to fund exploratory, proof-of-concept studies that test new ideas, generate preliminary data, or open up promising new research directions rather than large, definitive projects. In practical terms, the opportunity is aimed at investigators proposing creative, potentially transformative work that clarifies why HBV persists more stubbornly in HIV/HBV co-infection, identifies barriers to clearing HBV (such as immune dysfunction, viral reservoir biology, and treatment-related constraints), and develops strategies that could ultimately enable durable HBV control or eradication in this population. While the announcement mentions "clinical research," it explicitly states "Clinical Trial Not Allowed," meaning applicants must structure human-related studies so they remain observational, mechanistic, or otherwise non-interventional in a way that avoids triggering NIH's clinical trial definition for this specific call.

The overall scientific intent is to encourage research that pinpoints and addresses the unique obstacles to HBV cure when HIV is present. This can include understanding how HIV-driven immune alterations affect HBV-specific immune responses, how long-term antiretroviral therapy influences HBV replication and persistence, and how HBV reservoirs (including covalently closed circular DNA and integrated HBV DNA) behave differently under co-infection. It also points toward translational work that connects laboratory findings to patient-relevant biology, such as identifying biomarkers of HBV persistence or immune recovery in co-infected individuals, improving model systems that better reflect co-infection, or developing and refining therapeutic concepts that could later be tested in interventional trials under other mechanisms or announcements.

Eligibility is broad and includes a wide range of domestic U.S. organizations and, notably, also allows non-U.S. entities (foreign organizations) and regional organizations, which can be important given the global burden of HIV/HBV co-infection. Eligible applicants listed include state, county, city, township, and 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; tribal organizations that are not federally recognized; public housing authorities/Indian housing authorities; nonprofits with and without 501(c)(3) status (excluding institutions of higher education in those nonprofit categories); for-profit organizations (other than small businesses); and small businesses. The FOA also explicitly highlights additional eligible applicant types such as Historically Black Colleges and Universities (HBCUs), Hispanic-serving Institutions, Tribally Controlled Colleges and Universities (TCCUs), Alaska Native and Native Hawaiian Serving Institutions, and Asian American Native American Pacific Islander Serving Institutions (AANAPISIs), as well as faith-based or community-based organizations, eligible federal agencies, U.S. territories or possessions, and certain tribal governments that are not federally recognized. This breadth signals an interest in drawing ideas and capacity from many institutional settings, including those serving populations disproportionately affected by viral hepatitis and HIV.

From the source data provided, the program is categorized under Health as the funding activity area, uses a Grant as the funding instrument, and is associated with CFDA number 93.855. The opportunity was created on 2020-03-06 and shows an original closing date of 2022-01-07, indicating that the posted version reflects a specific submission window tied to that period. An award ceiling is not specified in the excerpt, and the expected number of awards is also not provided in the supplied data, so prospective applicants would normally need to consult the full FOA text and NIH notices for budget guidance, project period expectations, and any institute-specific priorities or paylines connected to PAS mechanisms.

In summary, PAS-20-121 is an NIH R21 call intended to accelerate innovative, non-clinical-trial research aimed at overcoming the scientific barriers to curing HBV in the context of HIV/HBV co-infection. It emphasizes creative and mechanistically grounded work that can illuminate why cure is difficult in co-infected individuals and can lay the groundwork for future therapeutic development, while keeping proposed studies within boundaries that do not constitute an NIH-defined clinical trial under this particular announcement.

• The National Institutes of Health in the health sector is offering a public funding opportunity titled "Research Towards Developing a Cure for HBV in HIV/HBV Co-Infection (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): 93.855.
• This funding opportunity was created on 2020-03-06.
• Applicants must submit their applications by 2022-01-07. (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 PAS 20 121

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