What exactly was the effectiveness against Delta? Prove it.
I live in a B10 college town. At the start of the spring 2022 semester(Jan) 95% of students and staff were boosted and masks were required. The virus still ripped through the university at similar rates to the local community. If my memory serves me correctly it was mostly Delta. Omicron didn't really kick in until March. The elderly even though vaccinated were still dying at rates equivalent to the previous winter. The elderly were more likely to vaccinated than the younger population at large.