UNC doctor working on Moderna trial explains how it differs from Pfizer vaccine, next steps in process

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Monday, November 16, 2020
UNC's role in the Moderna COVID-19 vaccine trial
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175 of the volunteers participating in the trial are at UNC.

CHAPEL HILL, N.C. (WTVD) -- Medical officials are expressing enthusiasm following Moderna's release of Phase 3 data, showing their vaccine was up to 94.5% effective.

"This is great. This is really a good day," said Dr. Cameron Wolfe, an infectious disease specialist at Duke's School of Medicine.

The findings come just a week after Pfizer announced similarly promising data.

"I think everyone was, myself included, was almost too impressed with the Pfizer data although I'm happy to take it at face value. (Now) here you've got a second trial, using the same sort of vaccine styles. This is a vaccine method that we've never used before," said Wolfe. "So to get two different companies using the same platform to come up with a similar vaccine, each with really outstanding efficacy, they kind of co-confirm each other."

Wolfe is referring to mRNA vaccines.

"They're done using vaccines harnessing part of the virus called mRNA. What that does - it's not a technique that we've have an opportunity to use for other infections before," Wolfe said.

Researchers optimistic about potential COVID-19 vaccine, though questions remain

"It could be really game changing, to be quite honest."

The Moderna vaccine included 30,000 volunteers, half of whom received the vaccine, the other half a placebo. UNC was a host site for one of the studies, and 175 participants took part in the trial there. Dr. Joseph Eron, the Chief of the Division of Infectious Diseases at UNC's School of Medicine, serves as an investigator for the Moderna trial.

"It's a remarkable result. I think we were hoping for 60, 70%. But it's really truly remarkable that it's so effective. And we learned also that in terms of severe disease, that no person that received the vaccine developed severe disease, which is really terrific," said Eron.

Moderna's results showed just five instances of a person receiving the vaccine and becoming affected, none of which involved serious symptoms. Still, the company cautioned the study is ongoing as scientists and researchers continue to study participants.

"What is the durability of this vaccine - the Moderna vaccine - and the Pfizer vaccine? And I think it's probably going to take at least a year to know for sure," Eron said.

While both the Pfizer and Moderna vaccines have very high efficacy rates, there is one key difference between them.

"It doesn't have the same cold-chain requirements as the Pfizer vaccine. I think that's the main difference. The Pfizer needs to be kept very, very cold - minus 70 degrees centigrade or lower," said Eron.

Of the 175 people who are taking part in UNC's study, about two-thirds come from underrepresented communities, which have been impacted by the pandemic greater than the national average.

While the results are encouraging, neither vaccine has been approved by the FDA at this time.

"Once the FDA has that safety data for two months on half the participants, then the FDA will decide whether something called an emergency use authorization, which means can this vaccine be distributed because it seems to have more benefit than risk. It's not a final approval, but it would get the final vaccine out there," said Eron.

Based on that timeline, and no marked changes to data, a vaccine could potentially be ready for roll-out in December or early 2021.

Moderna has publicly committed to providing 20 million doses for US patients by the end of the year; each patient receives two doses so that would impact 10 million people. Pfizer has committed to providing 50 million doses globally by the end of the year, though has not specified any number specifically for the American market. The U.S. government is hoping for at least 20 million doses from Pfizer by the end of the year, if not more.

"These companies have already been manufacturing doses on the anticipation and hope that they'll be effective. So I think as soon as the FDA clear then, then that will really change pace quite quickly, because then it's all about distribution and administration," said Wolfe.

"When we've spoken about having 40 million doses by the end of this year to be able to vaccinate 20 million people in the month of December, assuming FDA authorization, that's of course reliant on the Pfizer and Moderna vaccines, the ones for which we now have Phase 3 data," said Health and Human Services Secretary Alex Azar.

Full interview with Dr. Joseph Eron:

UNC Professor of Medicine Dr. Joseph Eron, who is an investigator in the Moderna trial, answers questions about the next steps in the road to a COVID-19 vaccine and the difference between the Moderna and Pfizer vaccines.