RE: COVID 1930 Apr 2020 21:18
'The research included four coronaviruses, HKU1, NL63, OC42, and C229E, which circulate widely every year but don’t get much attention because they only cause common colds. But now that a new coronavirus in the same broad family, SARS-CoV-2, has the world on lockdown, information about the mild viruses is among our clues to how the pandemic might unfold.
What the Columbia researchers now describe in a preliminary report is cause for concern. They found that people frequently got reinfected with the same coronavirus, even in the same year, and sometimes more than once. Over a year and a half, a dozen of the volunteers tested positive two or three times for the same virus, in one case with just four weeks between positive results.
That’s a stark difference from the pattern with infections like measles or chicken pox, where people who recover can expect to be immune for life.
For the coronaviruses “immunity seems to wane quickly,” says Jeffrey Shaman, who carried out the research with Marta Galanti, a postdoctoral researcher.'
https://www.technologyreview.com/2020/04/27/1000569/how-long-are-people-immune-to-covid-19/