Scientists at St. Jude Children’s Research Hospital have identified mutations in the hemagglutinin protein of flu viruses that can enhance or impair the effectiveness of influenza vaccines. The research reveals that a destabilizing mutation in hemagglutinin may result in a vaccine that poorly matches circulating flu strains. Conversely, a protective mutation exists that maintains hemagglutinin stability, suggesting a path to improve vaccine efficacy. The team emphasizes the importance of hemagglutinin stability in predicting the pandemic potential of flu viruses, as destabilized proteins hinder airborne transmission in ferrets—an animal model for human flu behavior. Successful transmission requires hemagglutinin to be stable enough to survive the acidic environment of the respiratory tract, yet unstable enough to allow rapid infection once in contact with target cells. While current assessments focus on changes to influenza virus receptor binding, the St. Jude study proposes that testing hemagglutinin stability could refine pandemic risk evaluations. This research presents a straightforward method to evaluate viral stability under different acidic conditions, potentially enhancing public health strategies in monitoring and preparing for influenza pandemics. The findings were published in Science Advances and supported by various health organizations.
