In an unprecedented move, on Sept 23, 2023, WHO recommended to no longer include influenza B/Yamagata in influenza vaccines for the next season in the Southern Hemisphere. Quadrivalent vaccines currently contain two influenza A viruses and both influenza B/Yamagata and B/Victoria. However, since the start of the COVID-19 pandemic, B/Yamagata levels have dropped substantially, and no such viruses have been isolated or sequenced since March, 2020. Therefore, WHO now states “inclusion of a B/Yamagata lineage antigen in quadrivalent influenza vaccines is no longer warranted, and every effort should be made to exclude this component as soon as possible”.