HHS-funded researchers are claiming to have engineered influenza-based chimeric “Frankenstein” viruses that combine influenza’s hemagglutinin (HA) with the SARS-CoV-2 receptor-binding domain (RBD) - a high-affinity human ACE2-binding interface.

Introducing a fundamentally different and stronger human cell–binding mechanism into an influenza viral system is a modification that fits longstanding U.S. gain-of-function definitions involving altered receptor usage and host range. [Read More]