The authorization of two coronavirus vaccines by the Food and Drug Administration makes it more complicated for other drug companies to get their vaccines through the clinical trial process. In this video from Motley Fool Live, recorded on Dec. 21, Corinne Cardina, bureau chief of healthcare and cannabis, and Fool.com contributor Brian Orelli discuss how AstraZeneca (NASDAQ:AZN) is dealing with participants in its study who might want to get the already-authorized vaccines. They also discuss the ramifications of the authorizations on clinical trial enrollment for companies that still need to run their phase 3 studies, such as Novavax (NASDAQ:NVAX) and Inovio (NASDAQ:INO).

Corrine Cardina: AstraZeneca, so they, of course, are working with the University of Oxford. And they have a bit of a dilemma with the U.S.-based clinical trial for their vaccine candidate. Now that there are two vaccines available in the U.S., obviously limited to the groups who are prioritized, but participants who received a placebo might want to get one of these authorized vaccines, especially if they're in a high-risk situation. What is going on with AstraZeneca and its clinical trials in the U.S.?

Brian Orelli: This is a report out of Endpoint News. Apparently, the AstraZeneca has told the investigators that running the clinical trials that they are allowed to let participants know whether they've received the vaccine or placebo, and then the participants can make a decision if they want to go and get the other vaccine. We'll continue to follow them, but obviously, they will be removed from counting data in terms of whether they developed COVID-19 or not. I think it's the right decision. It's definitely is going to make it harder for the company to generate results because now you're removing those people out of the efficacy results. But I think it's the right decision for AstraZeneca and for the participants who are willing to go into the clinical trial in the first place.

Cardina: Definitely. What is AstraZeneca's trial timeline?

Orelli: They have enrolled 23,000 people as of last week, I think, and then they are shooting for readout in February.

Cardina: Are there any implications for other vaccine makers that have not begun their phase 3 development in the U.S. Novavax, Inovio both come to mind.

Orelli: I mean, it's definitely going to make it harder. Who wants a 50-50 chance of getting placebo if there's 100% chance of getting the authorized vaccine. I think it's going to be much harder for them to get people into the clinical trials. I think the end result is that they're going to end up getting people who are lower down on the list, people who don't think that they're going to be able to get the vaccine anytime in the near future. That means those people are probably less at risk, so they are less likely to get the coronavirus, which is going to make the clinical trial go longer because it's an event-driven clinical trial, and so the events won't happen as quickly. Then also, with the vaccines coming out, now, hopefully, the infection rates go down as the people that are vaccinated won't be infecting people, hopefully. They'll have even less and fewer events, and so I think those clinical trials will take much longer.

Ultimately, they could run head-to-head comparisons and they could run comparison of their vaccine to one that's already authorized. But even that, might be a hard once availability is high because why would you want to go into a clinical trial testing an unknown vaccine against a known vaccine when the known vaccine works really well and you can get it. Once you can get it, that type of head-to-head comparison will be really difficult to run.

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