Some investors may hesitate before buying Novavax (NVAX 4.67%) these days. The shares have climbed 88% this year. That's after soaring more than 2,700% last year. And the company has fallen behind on the request for Emergency Use Authorization (EUA) for its coronavirus vaccine candidate. It plans to complete its filing with the U.S. Food and Drug Administration in the third quarter instead of the second quarter.

But I don't think those are reasons to avoid the stock. In fact, I see three much stronger reasons to buy shares of this biotech company right now.

A researcher works in a lab in front of a laptop.

Image source: Getty Images.

1. A latecomer that still could make billions

Countries around the world already have ordered 200 million vaccine doses from Novavax. The company also won a supply deal for 1.1 billion vaccine doses with Gavi, the Vaccine Alliance to provide equitable access to vaccines. Of course, the Gavi doses will carry a lower price tag than those to higher-income countries. Novavax hasn't specified the exact prices. But the lower and higher price levels together will bring in enough revenue to "rapidly" grow the business, Novavax says. In fact, Novavax expects to generate billions of dollars in revenue over the coming four to six quarters.

The European Union may represent a significant opportunity for Novavax too. The company currently is talking with the European Commission regarding a possible supply deal. The EU has struggled with vaccine shortages. And some member countries have shunned the AstraZeneca and Johnson & Johnson vaccines after reports of blood clots. So, there is opportunity for a newcomer in the region.

And finally, experts predict the coronavirus is here to stay. That means Novavax's revenue opportunity isn't limited to 2021. If the FDA and other regulators authorize the Novavax candidate, billions of dollars in revenue may be recurrent.

2. A combined coronavirus/flu vaccine down the road

Novavax is working on a combined coronavirus and flu vaccine candidate. Rival Moderna is too. But Novavax may be the best candidate to make this type of vaccine. Why? Because Novavax already has experience when it comes to flu vaccines. The company's NanoFlu last year met all primary endpoints in a phase 3 trial. And the combined vaccine would include NanoFlu along with Novavax's investigational coronavirus vaccine candidate.

The company says the launch of such a vaccine could happen in 2025. This is positive because it offers Novavax a potential post-pandemic revenue driver. At this point, people may not want to go for flu and coronavirus shots every year. As it is, a majority of the population usually doesn't go for a flu shot. About half of the U.S. population opted for one in the 2018-2019 flu season. We could imagine that percentage growing significantly if people are offered a vaccine that would protect them against the flu and coronavirus.

3. Still room for share price growth

Yes, last year's share gain and this year's increase are impressive. But that doesn't mean the Novavax stock market story is over. Novavax still has room to grow. For instance, the market cap of fellow vaccine maker Moderna totals more than $86 billion. And the market cap of Pfizer's vaccine partner BioNTech recently reached $57 billion. Novavax's market value is much lower than these biotech peers, at about $17 billion.

NVAX Market Cap Chart

Analysts predict Novavax could post earnings per share of about $30 next year. This is big -- especially when those earnings are thanks to a company's first commercialized product. We saw that Moderna reached profitability after just one quarter of vaccine sales. Novavax could follow in its rival's footsteps.

Wall Street expects the stock to advance 23% over the coming 12 months. That's according to the average estimate of analysts. This represents a satisfactory gain. But it's worth holding on to Novavax shares well beyond that. Revenue from the coronavirus vaccine in the near to midterm and a combined vaccine in the future are likely to drive share gains in the years to come.