Oxford Vaccine Group, the original developer of the COVID-19 vaccine marketed by AstraZeneca (NASDAQ:AZN), recently announced that it's conducting a clinical study evaluating multiple COVID-19 vaccines.

In this Motley Fool Live video recorded on April 21, 2021, Motley Fool contributors Keith Speights and Brian Orelli discuss whether Pfizer (NYSE:PFE) and Moderna (NASDAQ:MRNA) have anything to worry about from this study.

Keith Speights: Now in some other news, Brian, Oxford Vaccine Group in the U.K. is conducting what they're calling a mix-and-match clinical study of several COVID-19 vaccines. So what's going on with this particular study? And are there any reasons at all for Pfizer and Moderna to be concerned with what's going on with this study?

Brian Orelli: This Com-Cov study started with looking at participants who had already received Pfizer['s] and AstraZeneca's vaccine. Once they entered the study, they were either given for their second dose the same vaccine, or they were given a shot of the opposite: Pfizer and then AstraZeneca, or AstraZeneca and then Pfizer.

Oxford's now expanding that study to add more patients, and then giving them either the Moderna or the Novavax (NASDAQ:NVAX), or comparing the Pfizer to Pfizer and AstraZeneca to AstraZeneca.

I mean, we'll have to wait and see what the results are before we can know who's the winner or loser here. The first part with just the Pfizer and AstraZeneca, the data is expected next month. And then the data that includes the Moderna and Novavax people will come in June or July.

If the antibodies levels are the same or higher, it could open up an opportunity for some of the newer companies like Novavax to gain inroads into vaccination. Maybe if it doesn't matter whether you get Pfizer and they get Novavax -- or even if that's better than getting Pfizer and Pfizer -- then you can definitely see where this could be an advantage to Novavax as it gains authorizations in various countries.

Speights: Yeah. It could provide the biggest benefit to the newest player on the scene, Novavax, hopefully. Or they expect, they hope, to win Emergency Use Authorization pretty soon, so this could open up an opportunity for that company.

Now Brian, how do you think this might play into the potential that a third dose will be required for COVID vaccines?

Orelli: Yeah. This isn't testing that, this clinical trial isn't testing that, but that's certainly another option -- especially if it shows that the antibody levels are the same or higher, then that could also play into it as people start designing variant boosters. Then it may not matter what you got for your first two, you'll just get whatever variant booster you have available, assuming it doesn't change anything.

Speights: Yeah. You and I were talking before we went on the air about our preferences for which vaccine we prefer to get. I think if this mix-and-match study goes well, I think consumer preferences could become even more important going forward. Don't you think?

Orelli: It depends on what the data shows. I guess if the data shows that it doesn't matter, and you get basically the same result no matter what combination you get, then maybe it becomes less important and it's like the flu shot. Do you know what brand of flu shot you got? I certainly don't.

Speights: Yeah, I guess it comes down to, if there's a perception that vaccine A is better than vaccine B, and you can mix and match without any issues, then maybe you could see people gravitate to vaccine A. I don't know if vaccine A would be Pfizer or Moderna or who, but maybe we could see that.

Orelli: I think it depends on what the data shows, I think.

Speights: Right. It's a study for us to watch, because it could have some ramifications over the longer run with the COVID vaccine market.

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