[akrito]

It's because many more people are vaccinated. Assume 100,000 people are vaccinated and 10,000 aren't. If the infection rate in vaccinated population is 5%, and in the unvaccinated population is 50%, then out of 10,000 infected people, 5,000 will be vaccinated and 5,000 won't.

[landemva]

A couple years ago vaccines prevented almost all people from getting sick. Not anymore.

[walterbell]

CDC changed their definition in Sept. 2021, https://www.miamiherald.com/news/coronavirus/article25411126...

> Before the change, the definition for “vaccination” read, “the act of introducing a vaccine into the body to produce immunity to a specific disease.” Now, the word “immunity” has been switched to “protection.” The term “vaccine” also got a makeover. The CDC’s definition changed from “a product that stimulates a person’s immune system to produce immunity to a specific disease” to the current “a preparation that is used to stimulate the body’s immune response against diseases.”

[brazzy]

Most vaccines never had 100% effectiveness, especially the flu vaccine.

[zerocount]

Yep. That wasn't the goal for the Covid vaccine. It was to keep people from getting severe cases and preventing deaths. It works, but it should be targeted to high-risk individuals and not a blanket strategy that's not needed for the majority of the world's population.

[tomjen3]

I don't think the flu one ever did, and smallpox, rabies and Measels probably still do, though I wouldn't recommend testing it.

[ramesh31]

You need 90%+ vaccination rates to start seeing herd immunity, which is what we have for things like MMR.

[avereveard]

It's not a sustainable business, once polio was eradicated from territory, you lost all sales. New vaccines are more of what we'd call a subscription model.