Pfizer(NYSE:PFE) and BioNTech(NASDAQ:BNTX) recently won U.S. emergency use authorization (EUA) for their COVID-19 vaccine. An EUA for Moderna's (NASDAQ:MRNA) vaccine could be only days away. In this Motley Fool Live video recorded on Dec. 9, 2020, Healthcare and Cannabis Bureau Chief Corinne Cardina and Fool.com writer Keith Speights discuss which of these stocks is the best pick for investors right now.Corinne Cardina: From an investment standpoint, which of the three stocks that we are discussing that are a hair away from the finish line: Pfizer, BioNTech, and Moderna -- which do you think is the better buy today?

Keith Speights: [laughs] Let me say this. I think all three of these stocks still have upside potential. Not everything is baked into the share prices, even though Moderna, for example, has really skyrocketed this year. But I think all of them have some degree of upside potential.

I do think that more conservative investors would like Pfizer out of these three. Pfizer, of course, has been around for, I guess, around 150 years or so, and they're a successful company over the long term. They have lots of other blockbuster products already on the market, other growth drivers. Their COVID vaccine is obviously a big plus for Pfizer, but it's not the only arrow in the company's quiver. I think conservative investors would really like Pfizer because of its stability, its financial strength, its dividend, and its growth prospects.

Over the long run, if I had to guess, I would say probably Moderna may have the potential to be the biggest winner, just because it could be a platform kind of stock. The company has always thought that if the mRNA approach works with one disease, it could work with a lot of diseases.

Moderna already has about a dozen pipeline candidates. Their CEO has said that when the money starts rolling in, assuming it does from their COVID vaccine mRNA 1273, that they plan to really beef up their pipeline and potentially expand it to up to 50 programs in clinical testing. That could pay off big time over the next decade or so. I think Moderna still has potential, even though a lot of its growth for the COVID vaccine is already baked into the price.