Dr. Moncef Slaoui dismissed concerns that the government won’t have enough supplies to maintain its “aggressive” coronavirus vaccination plan, as the first doses of the Pfizer vaccine roll out across the country.

The chief medical adviser for Operation Warp Speed told host Chris Wallace on “Fox News Sunday” that six different vaccines are in development -- making it feasible for the government to meet its target of vaccinating over 100 million people by the end of March.

“Our plan from Day One has been to have a portfolio of products,” Slaoui said. “Pfizer is one of them. Moderna, which is likely to be approved by Friday, probably this coming week, is able to produce 100 million doses in the first quarter, and we just announced on Friday that we’ve committed to acquire another 100 million doses, which will be delivered in the second quarter of 2021.”

Dr. Moncef Slaoui, chief adviser to Operation Warp Speed, speaks in the Rose Garden of the White House, Friday, Nov. 13, 2020, in Washington. (AP Photo/Evan Vucci)

Dr. Moncef Slaoui, chief adviser to Operation Warp Speed, speaks in the Rose Garden of the White House, Friday, Nov. 13, 2020, in Washington. (AP Photo/Evan Vucci)

Slaoui also said that Johnson & Jonson’s vaccine was in the last stages of Phase Three trials, with expectations that the vaccine could be ready for authorization late in January or early February.

The Johnson & Johnson product would be a one-dose vaccine compared to the other vaccines that require two shots.

Slaoui also said he expects AstraZeneca’s vaccine to “potentially” be approved in late February, with another two vaccines likely to be approved after that.

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The main issue so far, Slaoui said, is “confusion” and concerns over the efficacy of the Pfizer vaccine, with over half of adults saying they are either unsure whether to take it or will refuse to do so, according to an Associated Press-Norc Poll.

Given the soaring death rates across the country, Slaoui said it would be a “very unfortunate outcome” if not enough people take the vaccine because they think it was rushed into production, compromising safety.

“I can guarantee you that no such thing has happened,” he said. “We have followed the science. It’s actually a remarkable achievement of science and academia, industry and the U.S. government system working relentlessly that has allowed this to happen.”

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In response to a question from Wallace, Slaoui said any pressure from the White House to cut corners would be "unfortunate and unnecessary.”