> My (and by proxy am guessing at the public's) understanding would be something like ~90% effectiveness at all but the most benign symptoms, and importantly mi

> My (and by proxy am guessing at the public's) understanding would be something like ~90% effectiveness at all but the most benign symptoms, and importantly minimal concerns of transmission. For example MMR Vaccines meet this standard [1] If you walk out on the street and ask people how effective the Flu vaccine is, I bet very few will tell you it’s around 90%. (It’s closer to 50%generally.) Most people are well aware that not all vaccines are hitting 90% protection bar. And again, to the extent that you’re right and I’m wrong, this is an argument in favor of the CDC making the definition clearer. I would expect that vaccines are most effective on viruses that mutate less. Influenza and coronaviruses both mutate quite a bit. It’s actually kind of impressive that the original COVID vaccine is still providing so much protection for later variants. > So I guess there is a middle ground between people expect the Covid vaccine to mean "you no longer can get it", and the reality of past vaccines "9x less likely to get it [at all vs hospitalization]" -- I just don't see the current covid vaccine providing the "get it at all" portion vs "hospitalization" target/success metric. I think part of this is because it is a moving target. Omicron is quite new (less than 2 months old) and it takes a while to gather meaningful data. Both Pfizer and Moderna demonstrated over 90% effectiveness on the original virus, in terms of reducing risk of infection at all. This dipped with subsequent variants like Delta and now Omicron. PBS says protection has dipped to 30-40% against infection and 70% against hospitalization, with a booster pushing it back up to 70-75 against infection, which is nothing to sneeze at considering that were several mutations away from the original at this point. https://www.pbs.org/newshour/amp/health/how-effective-are-covid-19-vaccines-against-omicron https://www.pbs.org/newshour/amp/health/how-effective-are-co...