Corona Measures Lead to Eradication of Influenza B Yamagata Strain

A significant impact of COVID-19 precautions has resulted in the absence of the B Yamagata flu strain, altering vaccination strategies.

The B Yamagata influenza strain has not been detected since 2020, attributed to COVID-19 preventative measures.
The World Health Organization concluded in September 2023 that the B Yamagata component is no longer needed in flu vaccines.
Germany is reverting to a trivalent flu vaccine, excluding B Yamagata, due to its apparent eradication.
The Ständige Impfkommission (Stiko) recommends the trivalent vaccine, but tetravalent vaccines remain available until the 2025/2026 season.
Experts urge caution as global surveillance is not comprehensive, leaving the possibility of B Yamagata's existence in under-monitored regions.