Advancements in Bird Flu Vaccine and Insights from Organoid Research Reveal Impact of H5N1 on Airways

Researchers at the Texas Biomedical Research Institute have made significant progress in developing a new vaccine aimed at protecting individuals from the current bird flu strain circulating in the United States. Led by Professor Luis Martinez-Sobrido and Staff Scientist Ahmed M. Elsayed, the team recently published promising initial findings in npj Vaccines, demonstrating the efficacy of their vaccine candidate. This live attenuated vaccine contains a weakened version of the avian influenza virus, which has been responsible for infections in poultry and dairy cattle since March 2024 across the U.S. Notably, a single dose proved sufficient to safeguard mice from deadly H5N1 infections in laboratory tests. The goal is now to adapt the vaccine to target other prevalent bird flu strains worldwide that are carried by migratory birds and waterfowl.

The ongoing outbreaks of H5N1 have affected multiple mammal species, from sea lions to domestic cats and dairy cattle. The virus has already sickened over 70 people in the U.S., with at least one fatality, primarily through contact with infected animals. Experts express concern that the virus could mutate and gain the ability to spread easily between humans, potentially triggering a severe pandemic. Current U.S. stockpiles include vaccines based on older, killed virus strains, which are effective against the current H5N1 outbreak. However, live attenuated vaccines are believed to offer more durable and robust protection.

Furthermore, organoid research has shed light on how H5N1 damages airway tissues. Using human airway organoids—3D mini-tissues that replicate the cellular environment of the human respiratory tract—researchers observed that the virus induces significant inflammation and prompts scar tissue formation, notably more severe than seasonal flu. They identified the ROCK pathway as a key driver of the resulting fibrosis, discovering that inhibiting ROCK1 enzyme effectively reduces airway scarring. These insights could pave the way for targeted therapies to mitigate respiratory damage caused by bird flu and other viruses like SARS-CoV-2. The research emphasizes the importance of understanding tissue-level responses, highlighting organoids as powerful tools for developing effective treatments.

For further details, see the original studies: npj Vaccines and Emerging Microbes & Infections.