Influenza B. It’s been spreading for decades. That being said we mostly have a partial immunity to it.

I had influenza B in early January and had pneumonia. 105 fever for a week, difficult to breath, the whole thing.

During that time I actually looked up and found out about COVID-19. I tested positive for influenza B, but the information actually let my family prepare by stocking up in January. Lucky in a sense.

Yes. Hundreds of millions of people get pneumonia every year. (But most causes of pneumonia have effective treatments or vaccines, while covid-19 does not.)