In the earliest days of the coronavirus vaccine race, Novavax (NVAX 3.54%) stood out as a potential winner. As a result, investors bet on the company and drove up its share price more than 2,700% back in 2020.

Since then, however, the story hasn't been as bright. Novavax fell behind, launching its vaccine as late as 1 1/2 years after rivals Pfizer and Moderna.

As a result, Novavax lost out on the biggest revenue opportunity, and its shares have been on the decline ever since. Still, Novavax brought in nearly $2 billion in revenue last year, thanks to its vaccine, and aims to launch an updated version for the fall season.

But it may find itself a step behind, once again. The U.S. Food and Drug Administration (FDA) just gave Pfizer and Moderna the nod for their updated jabs but is still reviewing the Novavax submission. Should investors be worried?

Missing out on sales

First, here's a quick look at Novavax's path, so far. As mentioned, the company missed out on the early surge in demand for coronavirus vaccines. By the time Novavax's vaccine launched, most of the people who wanted one had already gotten one.

Of course, Novavax's product may appeal to certain individuals who didn't want to get the messenger RNA vaccines developed by rivals or have had trouble with side effects after those vaccines. Novavax's protein subunit vaccine relies on technology used in other commercialized vaccines, such as the one for hepatitis B. So it isn't a brand new method, like the one involving mRNA.

So far, though, this hasn't helped Novavax gain much market share, as Pfizer and Moderna have vaccinated most Americans.

As we head into the fall vaccination season, it's likely that people who want a booster and are immediately eligible for one will go for what's available. That's because health experts generally recommend getting respiratory boosters early in the season.

If Pfizer and Moderna hit the market first, their products could dominate. To what extent will depend on the lapse of time between a Pfizer/Moderna launch and a Novavax one. If it's a matter of days, it probably won't make much difference. But if weeks go by, it could be bad news for Novavax.

The Centers for Disease Control and Prevention just signed off on the updated Pfizer and Moderna vaccines, recommending them for people ages six months and older, and vaccination could start as early as this week.

A restructuring plan

It's important to remember that Novavax already has had its share of troubles, due to the lower-than-expected vaccine revenue, so far. The company earlier this year questioned its ability to stay in business and launched a major restructuring plan that involved cutting 25% of its employees. The goal was to reduce costs by as much as 50% next year, compared with last year's level.

Now let's get back to our question: Should investors be worried about this latest turn of events? Not necessarily.

Yes, any delay could hurt Novavax's ability to gain share in an already difficult market. But even if Novavax's product comes out at the exact same time as those of rivals, it still may struggle to carve out a position. Pfizer and Moderna already are market leaders, and healthcare providers might prefer sticking with these vaccines -- and companies -- they know well.

Does this mean you should turn your back on Novavax? It depends on your comfort with risk. If you're an aggressive investor looking for a recovery story, you may want to scoop up a few shares of Novavax.

Even if near-term vaccine sales lag behind rivals, the stock could rebound if Novavax makes progress on its restructuring plan and moves forward with its combined coronavirus/flu vaccine candidate. The combined candidate has delivered positive results in clinical trials and could be a successful product down the road.

But if you're a cautious investor, it's best to avoid this biotech player for now as it continues along what may be a bumpy road to recovery.