So I’ve seen repeated comments here and elsewhere in the last week that getting Covid-19 does not guarantee future immunity to it.

Now, I’m not a great believer in absolutes - guarantee is not a word I’m fond of. But my understanding was that documented cases of people re-catching the disease were very, very sparse. Like, single-digits sparse as of a couple months ago. I would not, on my current knowledge, be afraid to characterize someone who had it once as functionally immune.

Have I missed some major reporting on this? Does anyone have links?