Approving a vaccine in the U.S. usually takes years, but COVID-19 vaccines are moving through in record time. What does that mean?


Could an approved coronavirus vaccine be released prior to Election Day on Nov. 3? It’s extremely unlikely – but not impossible – experts say. 

President Donald Trump on Monday said, “vaccines are coming momentarily,” and he has promised on multiple occasions that one will be ready before the election, now less than a month away.

For that to happen, though, three things would be necessary:

  • First, extremely positive data from ongoing Phase 3 clinical trials would have to be released showing a candidate vaccine to be extraordinarily effective. 
  • Second, the vaccine manufacturer would have to apply to the U.S. Food and Drug Administration for its approval.
  • And third, the FDA likely would have to ignore its own guidelines for companies seeking authorization.

On Tuesday, the FDA updated those guidelines for COVID-19 vaccine emergency use authorizations, requiring at least two months of follow-up data after trial volunteers take the necessary doses.

“This is a scientific agency applying scientific standards,” said Gillian Woollett, a senior vice president and expert on FDA guidance and regulatory issues at the health care consulting firm Avalere Health.

Pfizer is furthest along in US Phase 3 vaccine trials after starting July 27

The updated guidance makes it a long shot that a vaccine could be approved for use before the election.

The timing is tight. There are four COVID-19 vaccines currently in Phase 3 clinical trials in the United States. The candidates from the two companies that started first, Moderna and Pfizer, both require two doses. Of those, the furthest along is the Pfizer vaccine. It requires two doses given 28 days apart.

Pfizer launched its U.S. Phase 3 trials on July 27. The second shots would have begun on Aug. 24. Two months of follow-up after that second shot would be Oct. 23. 

President Donald Trump says COVID-19 vaccines are coming ‘momentarily.’ Scientists say they’re not.


U.S. Surgeon General Jerome Adams said during a stop in Texas Monday that a vaccine against COVID-19 could be ready as soon as the end of this year or early 2021. But he isn’t saying when Americans might be able to get it. (Sept. 28)

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It’s not clear, however, how many volunteers were immediately enrolled in the clinical trial but it likely started small. Such trials tend to start slowly so potential problems can be addressed. 

It could take several weeks or months for Pfizer, or any COVID-19 vaccine maker, to have enough volunteers go through both doses followed by the two-month follow-up to have enough data to present to FDA.

That’s when the real countdown begins. Only when a company, in this case, frontrunners Moderna, Pfizer, AstraZeneca, or Johnson & Johnson, applies for either a license or the more rapid emergency use authorization that the FDA can begin evaluating whether to allow a vaccine’s release.

This Aug. 2, 2018, file photo