The 95% effectiveness was calculated from two cohorts of ~21K people each. The vaccinated cohort had 0.03% infected (about 7 cases) and the unvaxxed group had about 0.7% infected, or about 140 cases. 7/140 = 5%, so there were 5% as many cases in the vaxxed group, so that is a 95% less than the unvaxxed group.
Never mind that both groups have a very low risk of infection, must less chance of it advancing to severe. And for anyone who is taking vitamin D, both those percentages are reduced by 90% or more.
The 95% effectiveness was calculated from two cohorts of ~21K people each. The vaccinated cohort had 0.03% infected (about 7 cases) and the unvaxxed group had about 0.7% infected, or about 140 cases. 7/140 = 5%, so there were 5% as many cases in the vaxxed group, so that is a 95% less than the unvaxxed group.
Never mind that both groups have a very low risk of infection, must less chance of it advancing to severe. And for anyone who is taking vitamin D, both those percentages are reduced by 90% or more.