This study is ridiculous. The way it's worded, it makes it sound like Omicron is immune to previous infection. What they didn't study specifically was immunity of Omicron to previous Omicron infection.

We all know that Omicron defeated previous immunity, but once you get infected by Omicron, you're immune to Omicron variants. This is basic science, and the fact that some doctors were trying to convince previously-infected people to get vaccinated was anti-science.