This may be worrisome ?

[Challenger340]

Seems Koreans are reporting many people who have been sick and already recovered from COVID-19 can be re-infected ?
which if true may pour some cold water on hopes at eventual Herd immunity to this thing ?
Korean's aren't the only ones..... the Hong Kong Chinese had some initial anti-body data levels suspect to re-infection.... but the Communist China Gov't since shut down the Hong Kong Site and quashed the data ?
https://www.cbc.ca/news/world/south-korea-coronavirus-covid19-reactivated-positive-1.5529066

The plot thickens.... this seems to me more like a custom built Virus ? because if true it's another FIRST for a 'coronavirus' in nature.
Let's hope those showing re-positives were just re-lapses or false 'all clears'

[Q5XX29]

That is the problem with the Coronavirus family- reinfection is not uncommon, and that is probably due, at least in part, to minor mutations in the virus over time that make it harder for your body's immune memory to keep you protected forever. Same reason why people get colds over and over throughout their lifetime; recall that many "common colds" are from milder types of corona virus. This is why developing a vaccine for this is particularly challenging, and why herd immunity may not be our savior here. The good news is, if an individual DOES get reinfected within, say, a year or two of the initial infection, it is more likely to be a much milder clinical course. SARS-Cov-1 seemed to confer immunity after infection for a couple of years.