What happened

Vaccine maker Novavax (NVAX -4.32%) saw its shares jump 12.57% on Friday. The stock closed at $17.18 on Thursday and opened at $17.27 on Friday. It climbed to as high as $19.46 before closing at $19.34. The stock has a 52-week low of $16 and a 52-week high of $236.50. So far this year, its shares are down more than 86%.

So what

It's been a curious week for Novavax. On Wednesday, the pharmaceutical company announced that its COVID-19 booster vaccine, adjuvanted (NVX-CoV2373) had been granted Emergency Use Authorization (EUA) by the Food and Drug Administration (FDA), and the stock slumped nearly 4% because of limits on the vaccine put forth by the FDA, saying it would only be for those adults who request it or for whom mRNA-type vaccines, such as those provided by Pfizer-BioNTech or Moderna, are not available or appropriate.

On the same day the FDA acted, the Centers for Disease Control and Prevention (CDC) released a memo giving adults who had already gotten a primary-series vaccination the option to receive Novavax's booster instead of the Pfizer-BioNtech or Moderna boosters.

There's a good chance that by Friday, investors did the about-turn because they realized that any kind of EUA was better than none at all and because NVX-CoV2373 has shown a good response to COVID variants. The EUA decision was based on data from the PREVENT-19 phase 3 clinical trial and from the U.K.-sponsored COV-Boost vaccine trial.

Now what

Novavax still has a lot that is dragging its stock down. If the COVID-19 pandemic continues to ebb, that won't help the pharmaceutical company. In the second quarter, it reported a net loss of $510 million with revenue of $186 million, down from $298 million in the same period last year. The company also downgraded full-year guidance to say it expected full-year revenue between $2 billion and $2.3 billion.

It's notable, though, that the company already has 2 billion doses of NVX-CoV2373 committed globally, including 110 million doses to the U.S. government. With $1.9 billion in cash, the company is in a good spot to handle the vaccine's rollout even if it has gotten behind other vaccines in the COVID game.