Moderna (MRNA 13.67%) has become a household name this year thanks to the rapid speed with which it has been developing and testing its COVID-19 vaccine candidate, mRNA-1273. The stock has also been a big winner, soaring more than 300% so far in 2020. 

But it's far from the only company attempting to develop coronavirus vaccine, and one far less well-known biotech in the hunt has seen its share price climb almost as much as Moderna's. That biotech is VBI Vaccines (VBIV -1.45%).

Which of these two coronavirus-focused biotech stocks is the better pick for investors now? Here's how they stack up against each other.

Gloved hand holding a COVID-19 vaccine syringe

Image source: Getty Images.

The case for Moderna

It's pretty easy to build an argument for buying Moderna. Most importantly, the company is among the leaders in the race to develop a COVID-19 vaccine. Moderna began a phase 3 clinical trial of mRNA-1273 on Monday.

The prospects for mRNA-1273 appear pretty good at this point. The vaccine candidate generated high levels of neutralizing antibodies (the kind of antibodies that prevent infection) and T cell response (a good sign for potentially providing longer-term immunity) in phase 1 testing. 

In April, the Biomedical Advanced Research and Development Authority (BARDA), a part of the U.S. Department of Health and Human Services, committed up to $483 million in funding for Moderna to help it speed mRNA-1273 through the development process. Earlier this week, BARDA added another $472 million to support the company's 30,000-person late-stage study of the vaccine candidate.

While mRNA-1273 rightfully is getting the lion's share of the attention right now, Moderna's pipeline includes other promising candidates. It's evaluating the experimental cytomegalovirus (CMV) vaccine mRNA-1647 in a phase 2 clinical study. It also has five other vaccine candidates in early-stage testing.

The biotech isn't just focused on vaccines for infectious diseases, though. It's working with AstraZeneca on an experimental therapy targeting the treatment of heart failure, an immunotherapy targeting solid tumors, and another candidate targeting coronary artery disease. It partnered with Merck to develop a couple of cancer vaccine candidates. And its pipeline includes four other wholly owned programs in phase 1 testing.

Liquidity shouldn't be a problem for Moderna. The company reported $1.7 billion in cash, cash equivalents, and investments on the books as of March 31. Since then, in addition to the funding commitments from BARDA, Moderna has raised around $1.34 billion through a secondary stock offering.

The case for VBI Vaccines

While Moderna is focused on a vaccine to immunize against SARS-CoV-2, VBI Vaccines is going after one that could protect people against all three of the major coronavirus threats -- the ones that cause COVID-19, SARS, and MERS. Right now, the biotech is conducting preclinical testing in animals of its pan-coronavirus vaccine candidate VBI-2901 with a goal of advancing to phase 1 clinical trials in humans at some point in the not-too-distant future.

Unlike Moderna, VBI isn't strictly a clinical-stage company. Its hepatitis B vaccine Sci-B-Vac is already approved in Israel. The company expects to file for approval with regulators elsewhere, notably including the U.S., Canada, and European Union, starting in the fourth quarter. 

While Sci-B-Vac is designed to prevent hep-B infections, VBI is also evaluating VBI-2601 in a phase 1b/2a study as a treatment for hepatitis B. The company expects to report data from that study in the second half of the year.

Like Moderna's pipeline, VBI's also includes a CMV vaccine candidate, VBI-1501 -- it's currently in phase 1 trials. In addition, the biotech is evaluating immunotherapy VBI-1901 in a phase 1/2a study targeting glioblastoma multiforme, an aggressive form of brain cancer.

As of March 31, VBI's cash position totaled $35.8 million. Subsequently, the company raised around $54 million in net cash from a public stock offering. In May, it also established a debt financing facility with K2 HealthVentures that allows it to access up to $50 million.

The better coronavirus stock is...

Ordinarily, I'd say that a biotech with a product that has been approved in one country and is potentially well on its way to approval elsewhere would be a better investment than a biotech without anything on the market yet. However, the COVID-19 vaccine opportunity for Moderna isn't an ordinary one.

I think that the chances of mRNA-1273 earning FDA approval are pretty good. Moderna is preparing to manufacture 500 million doses of it per year; assuming it can sell that many, the company could be looking at annual revenue in the ballpark of $10 billion from the vaccine. And if mRNA-1273 is successful, it would bode well for the other candidates in the pipeline that the company developed using the same mRNA platform.

VBI Vaccines certainly has potential with Sci-B-Vac and the rest of its pipeline, including its pan-coronavirus vaccine candidate, VBI-2901. And with a market cap of around $1 billion, is only a fraction of the size of Moderna, which is valued at over $30 billion. But with mRNA-1273 in already beginning late-stage clinical testing, I see Moderna as the better COVID-19 stock right now.