Six companies are currently evaluating COVID-19 vaccine candidates in late-stage testing. Johnson & Johnson (JNJ 0.28%) isn't one of them.

J&J was among the first to commit resources to a major effort to fight COVID-19. It established a partnership with the U.S. government early on to develop a novel coronavirus vaccine. It's the biggest healthcare company in the world, with massive resources. And yet Johnson & Johnson lags well behind multiple rivals, both big and small.

Don't discount J&J's prospects, though. The healthcare giant's COVID-19 vaccine candidate could have an ace in the hole that just might make it the biggest winner of all.

Scientist in protective gear holding a vial labeled COVID-19 Vaccine in one hand, and giving a thumbs-up with the other

Image source: Getty Images.

One and done

Johnson & Johnson announced the publication of results from a preclinical study of its lead vaccine candidate, Ad26.COV2-S, on July 30. You might not think preclinical results would be a big deal. After all, several of J&J's rivals in the race to develop COVID-19 vaccines have already announced results from early-stage clinical studies in humans.

The company reported that its experimental vaccine induced a robust immune response in nonhuman primates. In particular, vaccination with Ad26.COV2-S resulted in the production of high levels of neutralizing antibodies, which hold the potential to prevent infection by the coronavirus. J&J noted that its vaccine candidate provided "complete or near-complete protection in the lungs from the virus" in the animals in the preclinical study.

All of that was great news. But what really made these preclinical results stand out was that the impressive immune response was obtained with only a single dose of Ad26.COV2-S. Other COVID-19 vaccine candidates that are farther along in clinical testing require two doses.

There are a couple of key reasons why a "one-and-done" vaccine is preferable to vaccines that require multiple doses. First, a single-dose vaccine is cheaper. Second, people would be more likely to receive a single vaccine dose than they would be to get both doses of a vaccine that requires two.

It's still early, though. J&J is evaluating both one- and two-dose regimens of Ad26.COV2-S in its phase 1/2a clinical studies. The company also plans to include both dosing regimens in its planned phase 3 study. There's a possibility that testing could lead J&J to go with the two-dose approach. However, if the single-dose vaccination works as well in humans as it did in nonhuman primates, Johnson & Johnson could easily vault from laggard to leader in the COVID-19 vaccine space.

Playing the long game

Johnson & Johnson arguably remains something of an underdog in the race to develop a COVID-19 vaccine. Even though the company expects to begin a late-stage study of Ad26.COV2-S in September, it's still well behind several other drugmakers. You also might be surprised that J&J has only won major regulatory approval for one vaccine -- ever. And that approval came last month, with European approval of the company's Ebola vaccine.

But J&J appears to be playing the long game pretty well with its COVID-19 vaccine development. It spent more time upfront to identify a candidate that could potentially be administered with only one dose. The company also is charging much less for its vaccine than its top rivals are. Last week, J&J landed a deal with the U.S. government to supply 100 million doses of Ad26.COV2-S for around $1 billion. By comparison, Pfizer and BioNTech are supplying 100 million doses to the U.S. for $1.95 billion.

Lower pricing with fewer doses required might not seem like a smart strategy. Couldn't J&J make a lot more money selling a two-dose vaccine regimen at a price more competitive with its rivals? Sure. The healthcare stock might even be up more year to date if it took this approach.

However, a single-dose vaccine would be much more attractive to governments across the world. And J&J is likely to sell it at cost while the pandemic is ongoing. After the pandemic ends, expect the company to raise its price.

Remember Aesop's fable about the tortoise and the hare? It looks like Johnson & Johnson could be the tortoise in the race to develop a COVID-19 vaccine. The tortoise might win the race in the real world -- just as it did in the fable.