Infection with respiratory viruses typically leads to strong immunity against severe disease.

“do we know if it's actually the norm that once you have a virus you tend to develop natural immunity to it i mean that was sort of my understanding from medical school but have things changed significantly and what would be our expectation here yeah so just real quick strep throat which is a bacteria that can re-infect you and re-infect you so you cannot have a viable vaccine respiratory pathogens in general you can get re-infected but your immunity against severe disease tends to be quite strong”