WHAT:
Influenza A virus particles strategically adapt their shape—to become either spheres or larger filaments—to favor their ability to infect cells depending on environmental conditions, according to a new study from National Institutes of Health (NIH) scientists. This previously unrecognized response could help explain how influenza A and other viruses persist in populations, evade immune responses, and acquire adaptive mutations, the researchers explain in a new study published in Nature Microbiology .
The study, led by intramural researchers at NIH’s National Institute of Allergy and Infectious Diseases (NIAID), was designed to determine why many influenza A virus particles exist as filaments. The filament shape requires more energy to form than a sphere, they state, and its abundance has been previously unexplained. To find the answer, they developed a way to observe and measure real-time influenza A virus structure during formation.
The researchers found:
Prior experiments by the research team showed that influenza A virus filaments can resist inactivation by antibodies, and the team is working to understand exactly how antibodies influence shape and infection efficiency. They also anticipate learning how viral mutations affect the shape of the virus. Many other viruses—such as measles, Ebola, Nipah, Hendra and respiratory syncytial virus—also incorporate a mixed-shape infection strategy, the researchers note.
ARTICLE:
E Partlow et al . Influenza A virus rapidly adapts particle shape to environmental pressures. Nature Microbiology DOI: 10.1038/s41564-025-01925-9 (2025).
WHO:
Tijana Ivanovic, Ph.D., is chief of the Single Virion Biology and Biophysics Unit in the NIAID Laboratory of Viral Diseases.
CONTACT:
To schedule interviews, please contact the NIAID News Office, (301) 402-1663, niaidnews@niaid.nih.gov.
NIAID conducts and supports research—at NIH, throughout the United States, and worldwide—to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID website.
About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit https://www.nih.gov/.
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