From zero to $40 billion in a year: That's what Bernstein analyst Ronny Gal expects for the COVID-19 vaccine market. Gal projects 2021 sales of coronavirus vaccines will approach that huge number, with the market being split among five drugmakers.

The companies with the highest sales dollars won't necessarily be the best-performing stocks, though. Relatively smaller biotech stocks with vaccines on the market will almost certainly deliver greater gains than huge drugmakers will. With that in mind, here are the three stocks that are likely to be the biggest winners from the massive COVID vaccine market that's on the way.

Vaccine vials forming a dollar sign with a few vials to the left and right of the dollar sign

Image source: Getty Images.

1. Novavax

Novavax (NVAX 3.54%) lags behind the leaders in the U.S., but its late-stage studies of coronavirus vaccine candidate NVX-CoV2373 are well underway in the U.K. The company anticipates reporting interim results from that U.K. study in early 2021. Novavax also hopes to begin its delayed U.S. late-stage study of the experimental vaccine within the next few weeks.

Assuming all goes well, Novavax could win emergency use authorizations (EUA) and approvals for NVX-CoV2373 in multiple countries in the first half of next year. Bernstein's Gal projects the biotech should rack up sales of $3.8 billion from its COVID vaccine.

That amount would put Novavax's NVX-CoV2373 in fourth place on Ronny Gal's ranking of the biggest-selling coronavirus vaccines in 2021. It would trail behind only Pfizer's (PFE 0.55%) and BioNTech's (BNTX 0.58%) BNT162b2, Moderna (MRNA 1.69%) mRNA-1273, and AstraZeneca's AZD1222, based on Gal's estimates.

However, Novavax is much smaller than any of these companies. If Novavax indeed pulls in $3.8 billion from NVX-CoV2373, it's a pretty safe bet that the biotech stock will be a bigger winner thanks to the lucrative COVID vaccine market than any of its larger rivals.

2. Moderna

It's unsurprising that Gal picked Moderna as the No. 2 biggest moneymaker in the coronavirus vaccine market next year: He projects sales of $11 billion for the biotech's mRNA-1273.

Sure, much of that estimated revenue total is already baked into Moderna's share price. But not all of it is. You can count on Moderna stock enjoying a solid bump when the revenue actually begins to roll in from its COVID-19 vaccine.

My view is that what Moderna is likely to do with its newfound wealth makes the stock a pretty good pick for long-term investors. CEO Stephane Bancel stated that Moderna will invest the money it makes from mRNA-1273 into expanding its pipeline to include up to 50 clinical programs.

Success for mRNA-1273 would go a long way toward validating Moderna's messenger RNA (mRNA) technology. I suspect that investors will more fully realize the platform potential that Moderna offers as its COVID vaccine racks up billions of dollars next year, driving this stock even higher.

3. BioNTech

BioNTech and its big partner, Pfizer, stand to make the biggest bucks of all in the coronavirus vaccine market next year. Gal looks for the two drugmakers to rake in a whopping $14.3 billion from BNT162b2. However, the vaccine's revenue will be split between Pfizer and BioNTech.

The German biotech stands to receive up to $563 million in milestone payments. It must repay its 50% share of development costs for the vaccine as BNT162b2 is commercialized, though. Pfizer and BioNTech haven't provided details on their revenue-sharing agreement, but it's likely that BioNTech will make several billion dollars from its portion of sales in 2021.

As is the case with Moderna, BioNTech also has a pipeline with other mRNA candidates. Look for BioNTech and Pfizer to focus heavily on advancing experimental mRNA influenza vaccine BNT161 into clinical testing. Investors are also likely to eagerly follow the company's progress in mRNA therapies for cancer.

BioNTech's market cap of around $30 billion reflects expectations of significant sales for BNT162b2. However, the stock could still enjoy a bigger boost than Pfizer and other big pharma stocks next year as those sales roll in.