People wait in line to register for a free flu vaccine provided by the L.A. Care and Blue Shield of California Promise Health Plans at the Community Resource Center in Lynnwood on September 22, 2023. Photo Credit: Genaro Molina/Getty Images
Health The WorldThis Flu Has Bid Us Farewell!
Since 2020, there have been no confirmed cases of the influenza B Yamagata lineage, prompting health agencies to remove it from flu vaccines, which has improved overall vaccine effectiveness.
Up until 2020, during each flu season, the number of confirmed cases of B Yamagata would peak, but without social contact, the flu virus couldn’t sustain transmission and eventually died out.
COVID-19 precautions – including social distancing, wearing masks, and travel restrictions – reduced the possibility of person-to-person transmission, a vital factor for any virus. Regulatory health agencies, including the World Health Organisation, the European Medicines Agency, and the United States Centres for Disease Control, recommended removing this lineage from flu vaccines, allowing other strains to be included in seasonal flu vaccines.
