What happened

Shares of BioNTech (BNTX -1.44%) are sinking 8.7% as of 11:07 a.m. ET on Friday. The biggest news for the company was positive. The U.S. Food and Drug Administration announced on Thursday that it is expanding the Emergency Use Authorization (EUA) for boosters of the COVID-19 vaccine developed by Pfizer (PFE) and BioNTech to include those aged 16 and 17.

This expanded EUA didn't cause the vaccine stock to fall, though. Investors could still be reacting to the announcement from Pfizer and BioNTech on Wednesday that a third dose of their vaccine neutralized the omicron variant. 

Also, the Centers for Disease Control and Prevention (CDC) published its Morbidity and Mortality Weekly Report on Friday. This report showed that the Pfizer-BioNTech vaccine was less effective than Moderna's (MRNA -0.74%) vaccine (75% versus 86%) in preventing COVID-19 hospitalizations among U.S. veterans over an eight-month period ending Sept. 30, 2021. Recipients of Moderna's vaccine also had higher antibody levels than those who'd gotten the Pfizer-BioNTech vaccine.

A healthcare professional giving a shot to a person.

Image source: Getty Images.

So what

BioNTech's share price hinges on expectations of future sales. If all the available COVID-19 vaccines were ineffective against the omicron variant, the company would have a much greater sales opportunity with an omicron-specific vaccine. However, this scenario seems to be a nonstarter since a third dose of the Pfizer-BioNTech vaccine already seems to be effective against the omicron variant.

The CDC's report could also mean that more people will choose the Moderna vaccine because of its higher efficacy. While this won't affect BioNTech's sales over the near term, it's certainly not great news for the company.

As for the FDA's EUA expansion of boosters to include 16- and 17-year-olds, it probably won't increase BioNTech's sales, either. The U.S. government has already ordered enough doses of the Pfizer-BioNTech vaccine to meet near-term demand.

Now what

BioNTech and Pfizer expect to have a vaccine specifically targeting the omicron variant available by March 2022. If this vaccine is needed, it could increase BioNTech's revenue next year.