At the beginning of 2020, Altimmune (NASDAQ:ALT) and Vaxart (NASDAQ:VXRT) were tiny biotechs with market caps below $30 million. They weren't even big enough to be considered microcap stocks. Most investors had never heard of either company.

Fast forward to today. Shares of both Altimmune and Vaxart have skyrocketed thanks to their respective COVID-19 vaccine programs, but many investors still haven't heard of these two fast-growing biotech stocks.

Which is the better coronavirus stock to consider buying? Here's how Altimmune and Vaxart stack up against each other.

A dollar sign in the middle of coronavirus cells.

Image source: Getty Images.

COVID-19 programs

Altimmune claims a couple of advantages over Vaxart when it comes to the two companies' COVID-19 programs. Its pipeline includes multiple COVID-19 candidates, compared to one for Vaxart. Altimmune's programs also have a head start.

On Aug. 10, 2020, Vaxart filed with the U.S. Food and Drug Administration for approval to begin a phase 1 study for its COVID-19 vaccine candidate. It's still waiting for the green light to initiate the study. Vaxart's COVID-19 vaccine candidate was also selected to be part of a preclinical challenge study funded by the U.S. government's Operation Warp Speed.

Meanwhile, the FDA authorized Altimmune to move forward with a phase 1/2 study of its lead COVID-19 therapeutic candidate, T-COVID. The company received $4.7 million in funding from the U.S. Army and Department of Defense for the clinical trial.

Altimmune also reported encouraging preclinical results in July for its COVID-19 vaccine candidate, AdCOVID. It's currently manufacturing doses to be used in a phase 1 study tentatively planned for the fourth quarter of 2020.

Both Altimmune and Vaxart have intriguing twists with their respective COVID-19 vaccine candidates. Altimmune's AdCOVID is administered intranasally, while Vaxart's vaccine is a tablet. 

Other pipeline candidates

Altimmune's pipeline includes several other clinical-stage programs. NasoVAX is an intranasal flu vaccine that completed phase 2a testing in 2019 and is ready for phase 2b testing. The company received FDA clearance to advance HepTcell into a phase 2 study for treating chronic hepatitis B. This study is expected to begin in the fourth quarter of 2020.

The Biomedical Advanced Research and Development Authority is funding phase 1 testing of intranasal anthrax vaccine candidate NasoShield. Altimmune also expects to begin a phase 1 study later this year evaluating ALT-801 in treating nonalcoholic steatohepatitis, a chronic liver disease.

Vaxart has a couple of programs in clinical testing. It completed a phase 1 study of a norovirus vaccine candidate. The company also completed a phase 2 proof-of-concept efficacy study of a monovalent flu vaccine. 

Both Altimmune and Vaxart have preclinical programs as well. Altimmune's ALT-702 targets solid tumors. Vaxart's preclinical vaccine candidates target influenza, respiratory syncytial virus, and human papillomavirus.

Financial position

Altimmune reported cash, cash equivalents, and short-term investments totaling $80.3 million as of June 30, 2020. Since then, the biotech has raised an additional $132 million in gross proceeds through a secondary offering of stock and warrants. 

Vaxart had $44.4 million in cash and cash equivalents as of June 30, 2020. Like Altimmune, it has raised additional cash through a stock offering, with roughly $90 million in gross proceeds.

Better coronavirus stock?

My view is that Altimmune deserves the nod as the better coronavirus stock at this point. The company has more COVID-19 programs than Vaxart does. It's received more federal funding. Altimmune has a deeper overall pipeline, and it's in a stronger financial position than Vaxart is.

However, I think it's too early for most investors to buy either stock right now. Investors should instead keep Altimmune and Vaxart on their radar screens. Clinical successes could very well make one or both of these biotech stocks worthy of serious consideration in the not-too-distant future.