Against infection, which:

> Incidence of infection was defined as the first PCR-positive or rapid antigen-positive test after the start of follow-up, regardless of symptoms.

> all rapid antigen tests conducted at health-care facilities (appendix p 9). SARS-CoV-2 testing is widely available and performed extensively in Qatar, mostly for non-clinical reasons.1, 12 Most infections are diagnosed not because of symptoms, but because of routine testing (appendix p 3).

So they’re even capturing non-symptomatic infections, which you may not really care about. If a booster turned a symptomatic infection into a non-symptomatic infection, it would still be captured here and make it look like a booster failure. Not sure how well Qatar captured symptomatic infections.

Relative effectiveness. It means you were 26% less likely to get COVID vs those with the vaccine but no booster