"A full course of the Pfizer-BioNTech vaccine is 64% effective at preventing symptomatic Covid-19, according to an early study by Israel’s health ministry reported Monday, much lower than previous estimates of nearly 90%.

The vaccine still appears to be highly effective, 93%, at preventing serious illness and hospitalization, the data shows, though this is also slightly lower than earlier studies suggested and for other variants."

Source: https://www.forbes.com/sites/roberthart/2021/07/06/pfizer-sh...

Also important and useful, but that's a different percentage. That's the percentage reduction as compared to a non-vaccinated (hopefully otherwise matched) group. This is the percentage of the population (here, healthcare workers) who got it. Which, frankly, is the percentage I care more about, personally, although for Phase 3 testing of vaccines of course the percentage you're talking about is what matters.

Given that my daughter, who got the Pfizer vaccine, is unlikely to be exposed to covid-19 virus MORE often than a typical healthcare worker, this is good news. I wish we had as good a study for Moderna and J&J, but hopefully we get one soon.