Pfizer said a clinical trial of its experimental COVID-19 vaccine found it to be more than 90% effective.

In this photo from Monday, Jan. 31, 2011, the Pfizer logo is displayed at the drug company’s world headquarters in New York. Pfizer Inc. said Tuesday, Feb. 1, its fourth-quarter profit nearly quadrupled from a year ago when it was weighed down by charges as revenue rose 6 percent, thanks to the addition of products from fellow drugmaker Wyeth, acquired late in 2009. (AP Photo/Mark Lennihan)