Not sure what this is supposed to prove. Younger, lower risk people were much more likely to have received 0-2 doses, and older and higher risk people were much more likely to have have gotten 3 or more doses.
I don’t understand how they came to the conclusion but the abstract claims an overall 30% reduced risk of infection, which IINM is similar to the flu shot. Far cry from the “95% efficacy” of mRNA vaccines (albeit against the worst outcomes) touted by early studies, but still significant.
