Tickled_Pink

There are many categories of diseases. With some like measles, chickenpox, etc your body develops lifetime immunity when contracted naturally.  Others, like the flu, don't.  Seems like covid is more like the latter.  On the plus side, there may still be hope for herd immunity over the long-term (as painful as it may be for humanity to eventually get there, and I'm not saying this is a public health strategy, it's a property of nature): "The number of healthcare workers with antibodies remained relatively high, which the researchers suggest may be due to regular exposure to the virus."  We also don't know much about the severity of it with multiple infections, although the flu has been pretty steady over the last 50+ years so that seems unlikely.

Herd immunity isn't likely, although annual vaccinations could eventually eradicate it, depending on how quickly immunity is lost and whether the virus has a chance to mutate. Covid appears to be closer to the common cold than flu. We do become immune to the common cold but that immunity is lost over time, which is why we get it again. Flu is different. It's constantly mutating, which is why a new vaccine is developed every year.