Let's talk about two companies developing COVID-19 vaccines that are much different from the ones we're generally used to. These two aren't going the traditional route of injecting a weakened version of the pathogen into the body. They have new ways of addressing the problem.

You've probably heard of Moderna (MRNA -1.75%) by now. Moderna has taken center stage over the past few months as it became the first company to bring a COVID-19 vaccine into human trials. The biotech company is developing a vaccine that harnesses the power of messenger RNA to instruct the body to make proteins to defend itself.

A woman holds a glass of water and shows two pills in her other hand.

Image source: Getty Images.

Vaxart (VXRT -12.49%) has emerged as another player with interesting technology. The company is working on an oral vaccine -- a pill -- that does its work in the small bowel. Vaxart recently said that Operation Warp Speed, the government's effort to help bring a COVID-19 vaccine to market, had selected its vaccine to participate in a non-human primate challenge study.

Two innovative companies

Which of these two innovative companies offers investors the best coronavirus buy right now? Here's a closer look.

Moderna and Vaxart are both clinical-stage companies, meaning they don't have commercialized products. Moderna's pipeline is larger and more advanced, with about 20 candidates in preclinical to phase 2 development. Besides COVID-19, Moderna's pipeline includes vaccines for other infectious diseases, cancer, and autoimmune disorders.

As for Vaxart, its pipeline includes four other candidates in preclinical to phase 1 for influenza, norovirus, respiratory syncytial virus (a cold-like virus), and human papillomavirus.

At the moment, the share price of both companies is all about what happens in the COVID-19 vaccine program.

Moderna stands several steps ahead of Vaxart when it comes to timeline. Moderna's vaccine entered a phase 1 clinical trial in March, and the company already has reported positive interim data from the study and started a phase 2 trial. Phase 3 will begin this month.

Easy road ahead -- or not?

Though this seems like smooth sailing, risks remain. Moderna's initial study involved younger participants only. Now, Moderna has begun testing on volunteers over age 55.

Success in older people is critical because COVID-19 has in many cases been deadly for the elderly. Moderna also has to show -- in all age groups -- that its vaccine can produce significant levels of neutralizing antibodies, the ones that block infection. The company so far only had neutralizing antibody data on eight patients.

Vaxart recently formed manufacturing partnerships to produce vaccine tablets for its first human trials, which it hopes to begin as early as this summer. In the meantime, the Operation Warp Speed study in non-human primates might offer clues about the vaccine's potential -- and open the door for government funding.

Though Vaxart reported encouraging preclinical results, with all tested animals showing immune response after one dose, it's too early to judge whether the technology will work in humans. The positive thing we do know about Vaxart's candidate right now has to do with logistics. Vaxart is working with two manufacturers for bulk production of a vaccine, but the tablet itself will be manufactured by Vaxart itself.

The company doesn't need the "fill finish" process (involving the filling and packaging of doses) used by injectable vaccines. Without fill finish, Vaxart avoids possible delays at busy manufacturing sites. And the other plus is that the Vaxart vaccine is room-temperature stable, meaning it's easy to store and transport to healthcare facilities.

The financial picture

As for the financial picture, Vaxart had nearly $30 million in cash as of March 31. Moderna has $2.4 billion to invest, the company said in its first-quarter earnings report. Vaxart, with shares that have increased 25-fold so far this year, has a market value of $842 million. Moderna shares have climbed 212%, giving the company a market capitalization of almost $23 billion.

Which biotech stock is the better one to choose? Without products on the market or proof that their technologies truly work in humans, both companies remain risky business for investors. But if I wanted to make a small investment outside my usual comfort level for risk, I would go with Moderna. So far, financials, study data, and timeline indicate the company may be more likely to win the coronavirus vaccine race.