Pfizer shares extended gains in premarket trading, rising about 15%, with BioNTech American depositary receipts up about 22%. The news added more than US$500 billion ($674.04 billion) to the value of the MSCI All Country World Index.
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.
