Researchers Target Viral Fusion for Universal Flu, HIV Vaccines

Michigan State University (MSU) researchers have received a new grant from the National Institutes of Health (NIH) to study viral fusion, a mechanism shared by influenza and HIV, with the goal of informing broadly protective vaccines and new antiviral therapies for both diseases. The project is led by David Weliky, PhD, a professor in MSU's Department of Chemistry, and focuses on the molecular machinery that allows a virus to merge its membrane with a host cell and deliver its genetic material inside.^1,2

Current Vaccines Leave Gaps in Protection

Seasonal influenza vaccines must be updated every year because the virus mutates rapidly, which limits how long a single dose can keep individuals protected.² The 2025-2026 season underscored the stakes: preliminary CDC estimates indicate at least 32 million illnesses, 390,000 hospitalizations, and 24,000 deaths, and the agency classified the season as moderately severe.³

HIV, meanwhile, still has no effective vaccine. According to UNAIDS, approximately 41.0 million individuals worldwide were living with HIV in 2025, with 1.2 million new acquisitions and 570,000 deaths from AIDS-related illnesses that year. About 5.0 million individuals living with HIV did not know their status.⁴

Targeting a Conserved Viral Engine

Viral fusion occurs when the membranes of a virus and a host cell join together, allowing the virus's genetic cargo to enter the cell and begin replicating.¹ Because this machinery is essential to viral function, it changes very little between strains, which the investigators liken to the same engine appearing across many makes and models of vehicles.²

That stability is what makes fusion an appealing target. A vaccine capable of halting the shared machinery could, in theory, protect against multiple influenza subtypes for several years, even as the virus continues to mutate.¹ The same principle could support a broadly effective HIV vaccine that targets fusion across many separate strains.²

In influenza, fusion is carried out by subunit 2 of the hemagglutinin protein (HA2); in HIV, it is driven by the gp41 envelope glycoprotein. Both proteins contain an N-terminal fusion peptide that binds the target cell membrane and is considered critical to the fusion process. Weliky's laboratory has previously used NMR spectroscopy to examine how these fusion peptides from both viruses interact with and alter lipid membranes.⁵

Mapping Fusion at the Atomic Level

The research relies on nuclear magnetic resonance (NMR), an analytical technique that uses a strong magnet and radio waves to reveal the structure and motion of atoms. Using instruments in MSU's Max T. Rogers NMR Core, the team plans to build a step-by-step picture of how influenza and HIV proteins change shape during fusion, along with the corresponding changes in the host cell membrane.¹

Weliky said the funding is essential for his group to "develop an integrated model of viral fusion" and to collect new data to test that model.¹

Tahmina Khatun, a graduate student in the Weliky group, framed the central question the project aims to answer: "Which forms of these viral proteins actually drive each stage of membrane fusion?"²

Implications Beyond Influenza and HIV

Because influenza and HIV are genetically unrelated, identifying fusion traits the 2 viruses share may also inform research on the broader family of viruses that rely on fusion to spread. These include coronaviruses and the viruses responsible for rubella, measles, yellow fever, and Ebola disease.²

Khatun noted that a clearer understanding of fusion could point to new ways of interrupting infection, including vaccines and antiviral drugs designed to block a virus before it ever enters a cell.²

What This Means for Pharmacists

The project remains at the basic science stage, and the announcement does not describe a specific vaccine candidate or a clinical timeline.^1,2 Still, the work reflects a broader shift in vaccine research away from strain-matched formulations and toward conserved viral targets that could reduce the need for annual reformulation.

Until such options exist, strain-specific seasonal influenza vaccines remain the primary tool for preventing influenza-related illness, hospitalization, and death, and pharmacists will continue to play a central role in administering them ahead of each season. For HIV, pharmacists remain key access points for testing, pre-exposure prophylaxis, and antiretroviral therapy support while vaccine research continues.

REFERENCES

1. Yeck C. MSU researchers work toward universal flu, HIV vaccines. MSUToday. September 29, 2026. Accessed October 16, 2026. https://msutoday.msu.edu/news/2026/09/new-nih-grant-supports-universal-flu-hiv-vaccines

2. Michigan State University. MSU researchers work toward universal flu, HIV vaccines. News release. EurekAlert! September 30, 2026. Accessed October 16, 2026. https://www.eurekalert.org/news-releases/1146013

3. CDC. Preliminary estimated flu disease burden 2025-2026 flu season. Accessed October 16, 2026. https://www.cdc.gov/flu-burden/php/php/data-vis/2025-2026.html

4. UNAIDS. Global HIV & AIDS statistics — fact sheet. Accessed October 16, 2026. https://www.unaids.org/en/resources/fact-sheet

5. Ghosh U, Weliky DP. 2H nuclear magnetic resonance spectroscopy supports larger amplitude fast motion and interference with lipid chain ordering for membrane that contains β sheet human immunodeficiency virus gp41 fusion peptide or helical hairpin influenza virus hemagglutinin fusion peptide at fusogenic pH. Biochim Biophys Acta Biomembr. 2020. Accessed October 16, 2026. https://www2.chemistry.msu.edu/Faculty/Welikygrp/Ghosh_BBA_2020.pdf