RT @enn_nafnlaus
Wow, convalescent ("natural") immunity acquired from Omicron infection looks to be terrible. Almost worthless against Delta, and even poor against Omicron itself.

https://www.medrxiv.org/content/10.1101/2022.01.25.22269794v1.full.pdf

I think I'll stop dismissing "they caught Omicron twice" cases as mere anecdotes.