You can do an antibody test to see if you got the coof - there's an antibody test that will show you had it before, as long as you're a pureblood it's 100% an accurate test.

Also it shows how little about the SOYENCE people know about COVID:

https://www.forbes.com/sites/williamhaseltine/2022/06/14/is-it-safe-to-fly-the-national-academy-of-sciences-engineering-and-medicine-weighs-in/

This is from a mainstream site. Basically, airplanes are one of the safer places to be in because there is YUGE cabin pressure (keeps you from physically blowing up) and very high ventilation and outside air. The filters for their AC/circulation system are super high commercial grade. You have more of a chance of getting the coof from waiting in line around others before and after the flight, so if you want to minimize chances of getting it, get in, get out, and GTFO as quickly as possible to minimize contact around people.

If you already got the coof a couple weeks ago even bettre, you're immune.