What happened

Shares of several vaccine companies were slipping on Wednesday. BioNTech (BNTX -2.07%) stock was falling 4.8% as of 12:31 p.m. ET. Ocugen's (OCGN -1.69%) shares were down 4%, and Novavax (NVAX 2.31%) stock was 3.6% lower.

There's one underlying reason behind these stocks moving lower: optimism that the omicron variant won't be as bad as initially feared. Hospitalization and death rates due to omicron appear to be much lower so far than previous variants.

A healthcare professional giving a person a shot in the arm.

Image source: Getty Images.

So what

Although vaccine stocks in general are down today, each individual stock has its own factors that will impact its future performance. BioNTech is the only company of the three with a COVID-19 vaccine already on the market in the U.S. It's still possible that the omicron variant could lead to increased orders for the vaccine that BioNTech and Pfizer have developed.

Ocugen has a license to commercialize Covaxin, a COVID-19 vaccine developed by Bharat Biotech, in the U.S. and Canada. So far, though, the company hasn't won authorizations or approvals in either market. Ocugen also hasn't secured any supply deals for Covaxin.

Novavax recently received conditional marketing authorization for its COVID-19 vaccine in the European Union. The company will begin supplying 100 million doses to EU countries beginning in January 2022. 

Now what

How the omicron variant plays out will be important to BioNTech, Ocugen, and Novavax. BioNTech and Pfizer are developing a version of their vaccine that specifically targets the omicron variant. The companies expect the omicron-specific vaccine will be available in March 2022. But Ocugen and Novavax also have other potential catalysts that are critical for the companies.

The U.S. Food and Drug Administration (FDA) placed a clinical hold on Ocugen's Investigational New Drug application to evaluate Covaxin. Ocugen is working to address the FDA's concerns so that clinical testing of the vaccine can begin. The company also awaits an FDA decision on Emergency Use Authorization (EUA) of Covaxin in children ages 2 to 18 years old.

Meanwhile, Novavax looks forward to several regulatory decisions. The company has filed for authorizations of NVX-CoV2373 in Australia, Canada, New Zealand, Singapore, and the U.K. The company's partner, SK Bioscience, has also submitted for approval of the vaccine in South Korea. Novavax expects to file for U.S. EUA of NVX-CoV2373 before the end of this year.

Editor's note: A previous version of this article stated that BioNTech is the only one of the three companies mentioned to have a COVID-19 vaccine on the market. Novavax's vaccine is available in Indonesia and the Philippines. The article has been corrected to clarify that only BioNTech's vaccine is available in the U.S. The Fool regrets the error.