A new study from the University of Pittsburgh and the National Institutes of Health (NIH) Vaccine Research Center has found that an Antibody Therapy can protect primates from severe illness caused by H5N1 avian flu.
The findings, published in Science, suggest that this prophylactic treatment could be a crucial tool in preventing severe disease and death in vulnerable populations if H5N1 continues to spread among humans.
A More Stable Approach to Flu Protection
Unlike traditional flu vaccines, which need annual updates to match the latest circulating strains, this antibody therapy targets a stable region of the virus, making it less vulnerable to mutations.
“This type of prevention can be very useful in controlling infection outbreaks and containing the bird flu pandemic,” said Dr. Douglas Reed, co-corresponding author and associate professor of immunology at Pitt’s School of Medicine.
The MEDI8852 antibody was tested in monkeys before exposure to H5N1. The results were promising:
- Monkeys pre-treated with a moderate antibody dose were universally protected from severe disease and death.
- The antibody remained effective for 8 to 12 weeks, suggesting it could offer temporary protection for first responders and healthcare workers during an outbreak.
- Researchers also determined the minimum serum concentration required for protection, providing a benchmark for future universal flu vaccine development.
Rising Concerns Over H5N1 Spread
While only one reported H5N1 case in the U.S. has resulted in death as of January 2025, the World Health Organization (WHO) has tracked over 950 cases globally since 1997, with more than half being fatal.
H5N1 is primarily spread by wild birds, poultry, and livestock, but recent genetic analyses indicate the virus is adapting to infect mammals more efficiently. The virus has already been detected in sea lions in South America, mink in Europe, and dairy cattle in the U.S.—raising concerns that it could evolve into a strain capable of human-to-human transmission.
A New Strategy for Pandemic Preparedness and Antibody Therapy
One of the most significant challenges in influenza prevention is the virus’s ability to rapidly mutate. Seasonal flu vaccines must be reformulated yearly to match dominant strains, but this antibody approach offers a more stable and long-lasting alternative.
“This antibody targets a region that does not vary across different influenza viruses,” said Dr. Simon Barratt-Boyes, co-corresponding author and professor of infectious diseases at Pitt’s School of Public Health. “Think about it as a tree—different species have different leaves, but their trunks look similar. The same goes for the flu virus: while surface proteins change, the stalk region remains stable, making it an ideal target for universal protection.”
Reference: Masaru Kanekiyo, Rebecca A. Gillespie, Kristine Cooper, Vanessa Guerra Canedo, Priscila M. S. Castanha, Amarendra Pegu, Eun Sung Yang, Luke Treaster, Gabin Yun, Megan Wallace, Gwenddolen Kettenburg, Connor Williams, Jeneveve Lundy, Stacey Barrick, Katherine O’Malley, Morgan Midgett, Michelle M. Martí, Hasitha Chavva, Jacqueline Corry, Benjamin R. Treat, Abby Lipinski, Lucia Ortiz Batsche, Adrian Creanga, Isabella Ritter, Reagan Walker, Emily Olsen, Amanda Laughlin, Daniel R. Perez, John R. Mascola, Eli A. Boritz, Yueh-Ming Loo, Wade Blair, Mark Esser, Barney S. Graham, Douglas S. Reed, Simon M. Barratt-Boyes. Pre-exposure antibody prophylaxis protects macaques from severe influenza. Science, 2025.
