Can someone good with data explain to me why there isn't a more tightly correlated relationship between case-fatality-rate for Covid, and vaccine uptake? If the vaccines prevent hospitalization and death, shouldn't we have seen a pretty significant drop in the case fatality rate as vaccines were deployed? Instead, it flat for almost the whole year, then dropped slightly from 1.8% to 1.6%. The introduction of omicron has sent it to a freefall, by contrast.