The fall/winter second wave thing appears to be a meme for the coronavirus.

Brazil and fucking India are hot as hell and they are COVID hotspots. Florida, Texas, Arizona, California, hot weather. All COVID hotspots.

Yeah the flu is coming back in the fall but we never shut down over a flu in a century.

If there is gonna be a second wave at all in the fall, it will be from re-opening schools. I don't think the virus cares all that much about the weather. Common cold coronaviruses are also all-season type of viruses. The flu is more seasonal in the flu and winter months.