Health-care companies fell slightly even as the Food and Drug Administration moved towards granting the first U.S. emergency-use approval for a Covid 19 vaccine.

A panel of independent experts recommended the U.S. drug-safety agency approve the vaccine -- and formal approval could come Saturday. But investors are still concerned about adoption of the vaccine and potential logistical issues with its distribution.

"This is an important part of the market narrative how the Pfizer and BioNTech vaccine is going to be delivered and distributed and of course the vaccines themselves," said Quincy Krosby, chief market strategist at Prudential Financial. The vaccine approval "portends a brighter spring," said Ms. Krosby, but there remains "the gap between today and when the general population begins to be vaccinated."

Moderna shares rose after-hours after the biotech concern said the U.S. had exercised an option to buy an additional 100 million doses of its Covid-19 vaccine candidate.

Shares of Certara surged on their first day of trading after the health-care technology company's initial public offering priced above its expected range.


 Write to Rob Curran at rob.curran@dowjones.com 

(END) Dow Jones Newswires

12-11-20 1754ET