Overview
- France’s Institut Pasteur said an H5 virus that adapts for human transmission could cause a pandemic possibly more severe than COVID-19, though experts rate the current likelihood as low.
- A multinational team led by Cambridge and Glasgow identified PB1 as the key determinant of thermal tolerance that enables certain avian strains to replicate at febrile temperatures.
- In animal models, raising body temperature curtailed replication and disease from human-origin influenza but did little to stop avian-origin viruses.
- Researchers note that gene swapping through reassortment can occur during co-infections, and PB1 transfers from avian strains contributed to the 1957 and 1968 pandemics.
- Health agencies report persistent H5N1 clade 2.3.4.4b outbreaks in birds and spillover to mammals in the Americas, sporadic human cases with historically high fatality, and readiness with candidate vaccines and antivirals.