What happened 

The U.S. Food and Drug Administration (FDA) approved Comirnaty -- the COVID-19 vaccine co-developed by Pfizer (PFE) and BioNTech (BNTX -1.44%) -- for use in people aged 16 and older on Monday. The news drove shares of Pfizer and BioNTech up 2.5% and 9.6%, respectively. Fellow vaccine maker Moderna (MRNA -0.74%) also saw its stock price surge 7.6%.

So what

The decision marks the first time the FDA has granted full approval for a COVID-19 vaccine. Previously, Pfizer's and BioNTech's vaccine was being administered under an emergency use authorization. Moderna's and Johnson & Johnson's drugs have also received an EUA.

The approval comes at a time when COVID-19 cases counts are surging, driven in part by new coronavirus mutations such as the delta variant.

"Based on the longer-term follow-up data that we submitted, today's decision by the FDA affirms the efficacy and safety profile of our vaccine at a time when it is urgently needed," Pfizer CEO Albert Bourla said in a press release. "About 60% of eligible Americans are fully vaccinated, and infection, hospitalization, and death rates continue to rise rapidly among unvaccinated populations across the country."

A healthcare worker is administering a vaccine to a patient.

Image source: Getty Images.

Bourla believes that the approval could spur more people to get vaccinated. "I am hopeful this approval will help increase confidence in our vaccine, as vaccination remains the best tool we have to help protect lives and achieve herd immunity," Bourla said.

Now what 

The approval will likely result in more sales and profits for Pfizer and BioNTech. The approval also bodes well for Moderna, which used similar mRNA technology to develop its COVID-19 vaccine and achieved a comparable efficacy and safety profile to Pfizer's and BioNTech's drug. Investors, in turn, bid up shares of all three of these drugmakers today.