The pandemic is going to end. No more shutdowns. No more social distancing. And no more masks.

What remains unknown, though, is how long it's going to take. The first shipments of COVID-19 vaccines are like a light at the end of a tunnel. But until enough individuals are vaccinated to achieve herd immunity, the pandemic will continue. At some point, though, perhaps even by next summer, life will begin to return to normal.

One major remnant of the pandemic that's likely to carry over as a permanent fixture will probably be the coronavirus vaccines that were instrumental in ending the healthcare crisis. The companies that make these vaccines that become a regular part of life will make a tremendous amount of money.

Investors who buy the stocks of these vaccine makers now could enjoy huge returns over the next decade. Here are three COVID vaccine stocks that just might be the biggest winners in a post-pandemic world.

Person throwing a protective mask into a trash can

Image source: Getty Images.

1. Novavax

Novavax (NASDAQ:NVAX) should report interim results from a U.K. late-stage study of COVID-19 vaccine candidate NVX-CoV2373 in early 2021. The biotech hasn't begun a late-stage study of the vaccine in the U.S. yet because of delays related to manufacturing issues. But it expects to kick off this study within the next few weeks.

Based on early-stage results, expectations are high that NVX-CoV2373 will be very effective. With other leading coronavirus vaccines already reporting efficacy levels of 94% or higher, though, Novavax probably won't have a big competitive advantage on this front.

However, the company also hopes to win approval for its flu vaccine candidate NanoFlu. Novavax thinks there's an opportunity to join NVX-CoV2373 with NanoFlu in a combo COVID-19/flu vaccine for post-pandemic use. If COVID-19 becomes as seasonal as the flu, this combo approach could be a huge plus for Novavax since most individuals would prefer to minimize the number of shots they get.

2. Arcturus Therapeutics

Speaking of minimizing the number of shots, that's exactly what Arcturus Therapeutics (NASDAQ:ARCT) seeks to do with COVID-19. Most of the leading coronavirus vaccines (including Novavax's NVX-CoV2373) require two doses given several weeks apart. Arcturus' ARCT-021 is a single-dose COVID vaccine.

ARCT-021 also has another thing going for it: It uses messenger RNA (mRNA) technology. Why is that important? The leading vaccines from Pfizer and Moderna are also based on mRNA and achieved very high efficacy levels. That could bode well for ARCT-021. As an added bonus, Arcturus is developing a freeze-dried form of its vaccine that won't require ultracold storage. 

Arcturus' vaccine probably won't be a major player in the market in 2021. The company hasn't advanced ARCT-021 into late-stage testing yet. But it already has supply deals lined up with Israel and Singapore. Looking beyond next year, Arcturus could emerge as a top winner in the coronavirus vaccine market if ARCT-021 delivers on its potential.

3. Vaxart

How would you like a coronavirus vaccine that doesn't require a shot at all? Vaxart (NASDAQ:VXRT) could make it happen. The biotech is developing a single-dose COVID-19 tablet vaccine, VXA-CoV2-1.

Obviously, the convenience of Vaxart's oral vaccine could be a significant competitive advantage. But the ease of distributing and storing VXA-CoV2-1 could be just as much of a draw since it has no cold-chain requirements.

There's even a possibility that Vaxart's experimental vaccine could have an edge in efficacy. Based on pre-clinical testing, VXA-CoV2-1 appears to activate both systemic and mucosal immunity (immune responses that occur in mucosal membranes including the respiratory system). The current leading injectable coronavirus vaccines don't promote mucosal immunity.

Speculative picks

I'd be remiss if I didn't point out that these three biotech stocks are highly speculative picks. None of the three companies have products on the market yet. Their fortunes hinge on successful clinical testing of their pipeline candidates. Clinical studies can (and often do) result in failure.

Of the three, Vaxart is arguably the riskiest choice. Although VXA-CoV2-1 is promising, it's still only being evaluated in an early-stage clinical study. Novavax is the farthest along of the group with two experimental vaccines in late-stage testing. But it still faces significant risks in advancing its vaccine candidates.

Keep these risks in mind. But don't overlook the potential for tremendous returns. The advantages that Novavax's, Arcturus', and Vaxart's COVID-19 vaccines offer could make each of these stocks big winners in a post-pandemic world if all goes well.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.