(How does this logic work on the world??)

https://www.advisory.com/en/daily-briefing/2021/03/30/flu-season

This year's flu season was virtually nonexistent. That could be bad news for next year.

The flu all but disappeared amid the Covid-19 pandemic, thanks in large part to social distancing measures aimed at reducing the coronavirus's spread. But experts say there could be a downside: Scientists may struggle to predict what flu strains will dominate the next flu season—making it challenging to create effective vaccines….

…this year's flu season was "strikingly different," with nearly no flu in the Northern Hemisphere during the winter of 2020-21. Nor was there much of a flu season in the Southern Hemisphere…