Originally it was thought that COVID was a winter virus and in the summer it will disappear.
The west coast is showing that to be far from true this summer as COVID is raging through Arizona, California, Oregon and Washington. Hospitalizations are up and wastewater test are showing summer COVID levels are the highest they have been in 2 years.
Well, it takes time for good research and good science to catch up to modern problems. The pandemic showed us that more than ever.
5 years later researchers now believe they understand why the virus spreads more during summer.