'On Friday, Pfizer and BioNTech said their product tested on 18 to 64-year-olds gave a more effective immune response against influenza A strain than a licensed flu vaccine and was as effective against Covid as their existing product. But the vaccine was inferior in targeting the less prevalent influenza B strain. The shot was tested on more than 8,000 adults.'
https://www.ft.com/content/705af7c7-8333-4b54-9fe0-e0ed96d52706