Highly informative. This is the $64,000 question policy makers are wrestling with.
Here's the lead in:
Many Americans who haven't been closely following the stream of research, evolving opinions and changing recommendations of health-care professionals and organizations probably don't realize just how little we know about the virus.￼
Few realize that when health care professionals and epidemiologists recommend these shutdowns, they're doing so based on evidence that, if left unchecked, the virus can overwhelm health-care systems relatively quickly, like it did in Wuhan. And while we know the lockdowns and social distancing have certainly helped, researchers and doctors can't say much more with certainty, ...
But the most critical unknown by far is how long do people remain immune from the virus once they contract it and recover? ...
And in this article by the MIT Technology Review, scientists explore the possibility that COVID-19 immunity just simply doesn't last.
And from the early part of the article itself:
For the coronaviruses “immunity seems to wane quickly,” says Jeffrey Shaman, who carried out the research with Marta Galanti, a postdoctoral researcher.
Whether covid-19 will follow the same pattern is unknown, but the Columbia results suggest one way that much of the public discussion about the pandemic could be misleading. There is talk of getting “past the peak” and “immunity passports” for those who’ve recovered. At the same time, some hope the infection is more widespread than generally known, and that only a tolerable death total stands between us and high enough levels of population immunity for the virus to stop spreading.
All that presumes immunity is long-lived, but what if it is fleeting instead?
"What I have been telling everyone—and no one believes me, but it’s true - is we get coronaviruses every winter even though we’re seroconverted,” says Matthew Frieman, who studies the virus family at the University of Maryland. That is, even though most people have previously developed antibodies to them, they get the viruses again. “We really don’t understand whether it is a change in the virus over time or antibodies that don’t protect from infection,” he says.
... Is there a chance the disease will turn into a killer version of the common cold, constantly out there, infecting 10% or 20% of the population each year, but also continuing to kill one in a hundred? If so, it would amount to a plague capable of shaving the current rate of world population growth by a tenth.