Note that it didn’t say immunity. The quoted number is saying the rate of hospitalization and death among the vaccinated is 90% lower than it is among the unvac

Note that it didn’t say immunity. The quoted number is saying the rate of hospitalization and death among the vaccinated is 90% lower than it is among the unvaccinated. It’s a simple calculation. Group a had X hospitalizations, group b had Y. Adjusting for population sizes, X is 90% lower than Y.