https://www.siliconvalley.com/2020/11/09/pfizer-says-early-analysis-shows-its-covid-19-vaccine-is-90-effective/

Drugmaker Pfizer said Monday an early look at data from its coronavirus vaccine shows it is more than 90% effective — a much better than expected efficacy if the trend continues.

The so-called interim analysis looked at the first 94 confirmed cases of Covid-19 among the more than 43,000 volunteers who got either two doses of the vaccine or a placebo. It found that fewer than 10% of infections were in participants who had been given the vaccine. More than 90% of the cases were in people who had been given a placebo.