I thought it was that 90% show production of antibodies.

No, they showed an antibody response in the spring. That's the easy part. This is the real-deal clinical trial: they gave tens of thousands of people the vaccine candidate, tens of thousands a placebo, and then counted the resulting cases for months, as well as watching for side effects. The 90% reduction is in actual cases.

The first line of the article states:

"The first effective coronavirus vaccine can prevent more than 90% of people from getting Covid-19, a preliminary analysis shows."

Problem is it is all from a press release. They can mangle words to be correct but very misleading. We will have to wait for the scientific paper which will take some time.

They say that every time they talk about vaccines but if you look at articles like this:

https://www.cdc.gov/flu/prevent/misconceptions.htm

and this

https://www.cdc.gov/flu/prevent/vaccine-benefits.htm

you'll see that that's not how it always works.

> Flu vaccination can reduce the risk of flu-associated hospitalization for children, working age adults, and older adults.