CNN is reporting that 114 South Koreans who were believed to have 'cleared' the virus after infection are now testing positive for Covid. It's unknown at this time whether it was due to re-infection or re-activation
either way, it's not good news. If it's only re-activation, then the next big question is how long the virus resides in the body after symptoms disappear. Is it a month?...3 months?...years? And the other big question is how infectious these people are between incidents. Apparently, there's a little worry that the covid virus could be more like the shingles virus and remain in the body for years; maybe for life....yikes!
on the other hand, if the cases were due to re-infection it significantly complicates the search for a an effective vaccine. If living thru the infection doesn't produce enough anti-bodies to fight off the virus short weeks later, the effective life of a vaccine may also be measured in weeks, without boosters, or maybe even with. But more than that is this would bring into question just how effective 'herd immunity' would be....as in not very. I remember reading about a study out of Europe that said that about 20% of Covid survivors showed almost no sign of anti-bodies in their system
this may be a novel corona-virus in more ways than one....kind of scary