It's possible the first bout was a false positive and the symptoms were from a different virus. It's possible. You would think immunity should be for several months at least.

Evidence mounts that covid19 immunity is short term, at least for some people. In other words, we may need to wear masks, social distance, and wash hands frequently for the rest of our lives. Additional evidence suggests the virus is contained in extremely small water droplets that can linger in the air for many minutes and travel to all corners of indoor spaces, which suggests HEPA filters and goggles over our eyes will also help minimize the infection rate.

There are many things about covid 19 immunity we do not know, but I shall now assume herd immunity will not occur and that vaccination will only keep us safe for a few weeks. I hope future research demonstrates these assumptions are incorrect.

Better safe than sorry.

"The times, they are a changin'. - Bob Dylan

At this moment, I consider schools opening this fall in the US to be deadly. There are more than 50 million school aged children. The covid infection rate with distancing and masks is about 1%, which may mean 500,000 infected children in a month with 1% death rate (5000 dead children). Those infected children would take their infection home, where masks and distancing do not occur, the infection rate unmasked is about 70%, and family members would be infected. That is at least ten times more deaths than school shootings, e.g., Columbine. Moreover, it would repeat until schools shut down.

I hope I've overestimated infections and deaths, but my fear is worse.