Coronavirus vaccine stocks haven't all shared the same fortunes. In this Motley Fool Live video recorded on Feb. 26, 2021, healthcare and cannabis bureau chief Corinne Cardina and contributor Adria Cimino discuss the most undervalued vaccine stock -- and vaccine stocks that have gained too much or too little investor attention.

Corinne Cardina: Let's do a quick little high-level summary. Of the COVID vaccine stocks that we are talking about today, which one would you say is the most undervalued at today's price?

Adria Cimino: The most undervalued, I would say is Pfizer (NYSE:PFE). The stock price is little changed last year, down 8% so far this year. It trades at 10 times forward earnings, which is the lowest in about a year. So I'd say Pfizer.

Corinne Cardina: Awesome. What would you say is the most overrated COVID vaccine stock?

Adria Cimino: I'd have to say Ocugen (NASDAQ:OCGN), because as we mentioned, we really don't know what's going to happen with Covaxin, and the shares are up 300% since the start of the year. It's little bit too much too soon for me.

Corinne Cardina: Totally. The most promising COVID vaccine stock for long-term investors.

Adria Cimino: I'd say Novavax (NASDAQ:NVAX). I think Novavax always seems to stay ahead of the game. They're always the first to announce. They announced last year they were going to investigate a combined flu and COVID vaccine, and they really have the expertise to do so. Now they're moving quickly into the strain-specific booster, investigating that. So I think Novavax.

Corinne Cardina: Awesome. My last one for this lightning round is: What would you say is the dark horse COVID vaccine stock for investors to watch?

Adria Cimino: I think it's maybe Vaxart (NASDAQ:VXRT). People have lost faith because of the whole neutralizing antibodies thing. But I think it's possible they could surprise us if the T-cells turn out to be able to handle coronavirus alone or if they figure out their booster shot -- I should say booster dose, because it's an oral vaccine -- works. That could be something that could definitely be the dark horse. But still, again, remain cautious. It's a risky stock.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.