> It looked at all these components of immunity up to eight months after infection and found that some of these "memory" cells responded to the coronavirus, or parts of it, in more than 90% of people, said Daniela Weiskopf, an immunologist who participated in the study. "This is good news," she said. The decline in response was slow, a sign that immunity could last a long time. But Weiskopf emphasized that "nobody knows" how things will look in a year or 18 months.

> Worldwide, there have been less than 30 cases of known re-infection among COVID-19 survivors, although more are suspected. Experts said the numbers would likely be much higher if most people had not developed immunity.

> "I think that tells us that there's some level of immunity after you've recovered from the primary infection," Wherry said. "We don't know how durable that is."

It's hard to read even this article as anything but "It seems there is a high level of immunity, but we don't know for sure, so let's be careful."

I don't know any reason to say otherwise, except if you are afraid people will get infected voluntarily for immunization.