TWiV reviews avian H5N1 influenza virus in the US, measles at highest levels in England, positive selection underlies repeated knockout of ORF8 in SARS-CoV-2 evolution, and cross-species spill-over potential of the H9N2 bat influenza A virus.

TWiV reviews the latest data on the UK variant of SARS-CoV-2, including some properties of the variant and why it is being closely studied, development of liver cancer in a participant in a adenovirus-associated virus gene therapy trial, and answers to listener questions.