Science . Pre-exposure antibody prophylaxis protects macaques from severe influenza H5N1

[tetano]

Science


. 2025 Jan 31;387(6733):534-541.
doi: 10.1126/science.ado6481. Epub 2025 Jan 30. Pre-exposure antibody prophylaxis protects macaques from severe influenza

Masaru Kanekiyo ¹ , Rebecca A Gillespie ¹ , Kristine Cooper ² , Vanessa Guerra Canedo ¹ , Priscila M S Castanha ³ , Amarendra Pegu ¹ , Eun Sung Yang ¹ , Luke Treaster ⁴ , Gabin Yun ⁴ , Megan Wallace ³ , Gwenddolen Kettenburg ³ , Connor Williams ⁵ , Jeneveve Lundy ⁵ , Stacey Barrick ⁵ , Katherine O'Malley ⁵ , Morgan Midgett ⁵ , Michelle M Martí ³ , Hasitha Chavva ³ , Jacqueline Corry ³ , Benjamin R Treat ³ , Abby Lipinski ⁵ , Lucia Ortiz Batsche ⁶ , Adrian Creanga ¹ , Isabella Ritter ⁷ , Reagan Walker ⁷ , Emily Olsen ^{3 5} , Amanda Laughlin ⁵ , Daniel R Perez ⁶ , John R Mascola ¹ , Eli A Boritz ¹ , Yueh-Ming Loo ⁸ , Wade Blair ⁸ , Mark Esser ⁸ , Barney S Graham ¹ , Douglas S Reed ^{# 5 9} , Simon M Barratt-Boyes ^{# 3 9}



Affiliations

• PMID: 39883776
• DOI: 10.1126/science.ado6481

Abstract

Influenza virus pandemics and seasonal epidemics have claimed countless lives. Recurrent zoonotic spillovers of influenza viruses with pandemic potential underscore the need for effective countermeasures. In this study, we show that pre-exposure prophylaxis with broadly neutralizing antibody (bnAb) MEDI8852 is highly effective in protecting cynomolgus macaques from severe disease caused by aerosolized highly pathogenic avian influenza H5N1 virus infection. Protection was antibody dose-dependent yet independent of Fc-mediated effector functions at the dose tested. Macaques receiving MEDI8852 at 10 milligrams per kilogram or higher had negligible impairment of respiratory function after infection, whereas control animals were not protected from severe disease and fatality. Given the breadth of MEDI8852 and other bnAbs, we anticipate that protection from unforeseen pandemic influenza A viruses is achievable.

[Pathfinder]

Tuesday, February 11, 2025

Single dose of broadly neutralizing antibody protects macaques from H5N1 influenza


NIH science lays groundwork for future studies in people.


Three influenza A (H5N1/bird flu) virus particles (rod-shaped). Note: Layout incorporates two CDC transmission electron micrographs that have been inverted, repositioned, and colorized by NIAID. Scale has been modified. CDC and NIAID

What


National Institutes of Health (NIH) scientists and their colleagues report that a single dose of a broadly neutralizing antibody (bnAb) administered prior to virus exposure protects macaques from severe H5N1 avian influenza. Highly pathogenic avian influenza (HPAI) H5N1 viruses have sporadically spilled over from birds into many other animals, including humans and dairy cows, in recent years. Although it has not yet acquired the capacity to spread readily between people, H5N1 has pandemic potential, which has spurred efforts to develop effective treatments and other countermeasures.

The investigators studied a bnAb called MEDI8852, which was discovered and developed by Medimmune, now part of AstraZeneca. MEDI8852 targets a portion of a key flu protein that is less prone to change than other parts of the virus and thus is capable of conferring protection against a wide range of flu viruses. In the new study, a group of macaques received an injection of MEDI8852 and were exposed to aerosolized HPAI H5N1 virus three days later. All the pre-treated animals survived and experienced no or very limited signs of disease. In contrast, a group of control macaques developed severe or fatal illness within a short time after virus exposure. Of note, the scientists determined that MEDI8852 remained in the body for a prolonged time after the injection. According to scientists, protection from severe disease would extend to weeks beyond antibody infusion, providing a realistic preventative window in the face of an H5N1 outbreak.

The research was conducted by Masaru Kanekiyo, D.V.M, Ph.D., and colleagues from NIH’s National Institute of Allergy and Infectious Diseases (NIAID) Vaccine Research Center (VRC) along with investigators from the University of Pittsburgh. It was published in Science.

Article


M Kanekiyo et al. Pre-exposure antibody prophylaxis protects macaques from severe influenza. Science DOI: 10.1126/science.ado6481 (2025).

Who


Dr. Kanekiyo, VRC, NIAID, is available to comment.

This research was supported by the Vaccine Research Center, NIAID, NIH, as well as grants R01AI154894 and UC7AI180311 and contracts 75N93021C00014 and HHSN261201500003.

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.

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https://www.nih.gov/news-events/news-releases/single-dose-broadly-neutralizing-antibody-protects-macaques-h5n1-influenza