If these numbers hold up, this is wonderful news. I just want to point out that this is more credible because Pfizer never took federal money to be part of Trump's Operation Warp Speed. Via Bloomberg:

The Covid-19 vaccine being developed by Pfizer Inc. and BioNTech SE prevented more than 90% of infections in a study of tens of thousands of volunteers, the most encouraging scientific advance so far in the battle against the coronavirus.

Eight months into the worst pandemic in a century, the preliminary results pave the way for the companies to seek an emergency-use authorization from regulators if further research shows the shot is also safe.

Pfizer shares extended gains in premarket trading, rising about 15%, with BioNTech American depositary receipts up about 22%. The news added more than $500 billion to the value of the MSCI All Country World Index.