FDA head explains why he’ll take the COVID-19 vaccine: “I have 100% confidence”

In March, a trial participant receives a shot in the first-stage safety study of a potential COVID-19 vaccine in Seattle.
Neal Browning receives a shot in March in the first-stage safety study clinical trial of a potential vaccine for COVID-19 at the Kaiser Permanente Washington Health Research Institute in Seattle.
(Ted S. Warren/AP)

Less than a year from when the world learned of the first cases of COVID-19, a vaccine could become available in the United States.

Never has a vaccine been developed, tested and approved so quickly. Such complex work normally takes 10 years or longer.

People across the globe are hoping that the vaccine will mean a more normal life. Yet many Americans continue to be unsure about lining up for shots, in part given the haste in bringing them to market.


Food and Drug Administration Commissioner Stephen Hahn answered questions from The Times about how the agency is reviewing the experimental vaccines and ensuring they will be distributed to Americans only if their benefits exceed their risks.

He said he has “100% confidence” in the process that will be on display Thursday when an FDA advisory committee discusses an experimental vaccine developed by Pfizer and its German partner BioNTech. Depending on the outcome of the meeting, a vaccine could be distributed within days.

A week after Thursday’s meeting, the committee is scheduled to review a second vaccine developed by Moderna.

This interview has been edited for clarity and brevity.

Under usual conditions, vaccines take a decade or longer to develop. How is the FDA ensuring that the COVID-19 vaccines are safe when all that complex work has been compressed to less than a year?

We’ve been working with the developers of vaccines to expedite that development but not allow for any corners to be cut.

So from the time of the identification of the virus to the development of a vaccine in the laboratory to the animal studies to the Phase 1, Phase 2, Phase 3 trials, and then on with respect to manufacturing, we’ve been doing everything in real time.


We have compressed our time frame for review, while at the same time still keeping our very strict criteria about safety and efficacy.

Pfizer and Moderna have asked the FDA for an “emergency use authorization” of their vaccines, which means they don’t need to take all the steps normally required to gain a license to sell a vaccine. Should that lower standard, which is in place because of the public health emergency, be a cause for concern?

No, I would not say that it’s a lower standard. We are using very similar criteria: clear and compelling evidence of safety and efficacy from at least one randomized Phase 3 trial.

We’ve required two months of follow-up safety data. That’s not the same length of safety data that we might get in a regular application, but we are putting in place a very vigorous surveillance/monitoring program.

We’re going to be transparent with people.

Is two months of following volunteers who took the vaccine really long enough to find all the possible adverse effects?

The overwhelming majority of side effects are seen within that two-month period of time.

I’m a doctor, I’m gonna take off my commissioner hat and put my doctor hat on. Whenever I would give informed consent to a patient about a medical procedure, I would tell my patients, I don’t have a crystal ball.


There are foreseen, predicted-by-the-literature side effects, and there are unforeseen side effects. We’re going to be very honest with the American people. We won’t be able to predict 100%. We’re confident with the data that we’ve covered the significant majority of serious side effects that might occur. But with any vaccine that we’ve approved in the past, and these as well, we need to continue monitoring because there is no system in the world that will 100% predict what’s going to happen in the future.

As FDA commissioner, you’ve been called to the White House at least twice to explain why it is taking so long to authorize the vaccines. Has that political pressure resulted in agency scientists being less aggressive in asking questions about these experimental products?

Absolutely nothing has kept us from asking the scientific questions that are necessary. We’ve been very clear about the questions and the answers that we would need to assess the safety and efficacy of a vaccine as well as the quality of manufacturing.

Since the vaccine trials included few people who were elderly, how will we know vaccines are safe and effective for nursing home residents, who are expected to be among the first to receive it?

We review what’s called line data, which is a line by line for the 44,000 subjects in the clinical trial. We’ve looked at subpopulations. For the question that you’re asking, we’ve looked at over 65, over 70, over 80. Very complicated data sets. Very complicated questions we’re asking.

Do you know how many people over the age of 80 were in the vaccine trials?


I believe that we can ultimately get those data out to you. I don’t want to promise something that might be considered confidential.

Is there anything that could prompt the FDA to halt distribution of a vaccine and rescind its authorization?

Well, let me be clear, we do not expect that to happen. It’s one of the reasons that we asked for clear and compelling evidence of safety and efficacy.

That being said, as with any medical product, not just this vaccine, the whole point of doing monitoring afterwards is if we do find issues related to efficacy or safety, we will revisit our decision.

Has the FDA already inspected the factories where the first two vaccines are being manufactured, and if so, what has the agency found?

At this point that is confidential commercial information. I can tell you that we have been very actively engaged, and in general, I can tell you we performed inspections. I can’t get into specifics at this point.


The Pfizer and Moderna vaccines both use a type of technology, based on messenger RNA, that hasn’t been previously used in a medical product? Has that posed a challenge for FDA reviewers?

It’s not something that is completely new to the agency nor to scientists. We feel very comfortable with the platform.

If you decide to authorize the vaccines, will you and your family get the shots?

I have 100% confidence in (the agency’s) brilliant, world-class scientists and in the gold standard that the FDA is. And when appropriate, I’ll be first in line, and I will encourage my family to be in line as well.