Extinction of the Influenza B Yamagata line during the Covid pandemic (2022)
pmc.ncbi.nlm.nih.gov
pmc.ncbi.nlm.nih.gov
In Europe, for 2024/2025, types A 'Victoria' and 'Thailand' (with type-B 'Victoria' and 'Yamagata' following closely, so you can see it's still there-ish) are expected to be the most virulent. but, as always with influenza, this might be wrong, which means vaccination might be slightly less effective, although still beneficial.
[0] https://www.ema.europa.eu/en/news/eu-recommendations-2024-20...
I thought, during the time, it was also felt that different respiratory viruses effectively out compete each other? Not seeing that mentioned much, at the moment.
I'm also somewhat terrified that folks seem to be taking this in the anti-vaccine direction.
There are a number of more plausible / simpler alternatives. For example: the innate immune system gets activated whenever you have an infection. This is the most primitive form of immunity that you have, and is blunt (fever, snot, generic immunoglobulins, etc.) but effective at warding off pathogens of any sort. It's why you don't often get two different upper respiratory infections at the same time.