What happened

Shares of Novavax (NVAX -4.32%) were tumbling 5.3% lower as of 11:17 a.m. ET on Thursday. The company reported positive results on Wednesday afternoon from studies evaluating its COVID-19 vaccine against the omicron variant. However, that good news wasn't enough to outweigh other developments that aren't as great for Novavax.

Three separate studies have been reported this week that indicate the omicron variant doesn't appear to be as concerning as some feared. Hospitalization rates in South Africa, England, and Scotland have been lower thus far with individuals infected by the omicron variant than with previous coronavirus strains.

In addition, the U.S. Food and Drug Administration granted Emergency Use Authorization (EUA) to Merck's oral COVID-19 therapy molnupiravir on Thursday. This follows the agency's EUA for Pfizer's COVID-19 pill on Wednesday.

A healthcare professional holding a syringe with needle and a vaccine vial.

Image source: Getty Images.

So what

The waning concerns about omicron have caused most COVID-19 vaccine stocks to fall in recent days. Investors who initially thought the new variant could spur a significant increase in demand for vaccines are rethinking those expectations.

However, Novavax's data for COVID-19 vaccine NVX-CoV2373 announced yesterday were encouraging. Two doses of the vaccine generated solid immune responses against the omicron variant. A third booster dose delivered an even greater immune response.  

Now what

The most important things to watch with Novavax are several regulatory decisions that are on the way. The company has filed for authorizations in multiple countries, including Australia, Canada, and the U.K. Novavax also expects to complete its filing for U.S. EUA for NVX-CoV2373 by year-end.