| USA TODAY
COVID-19: How Pfizer and Moderna’s vaccines differ
Pfizer and Moderna have both announced promising results in the phase 3 trials of their COVID-19 vaccines. Here’s how they differ.
A COVID-19 vaccine could come within weeks – at least a limited supply to front-line medical workers. Drug companies Pfizer, Moderna and AstraZeneca have the leading vaccine candidates. Several others remain in development.
The Food and Drug Administration is responsible for authorizing and approving all vaccines in the USA. Widespread vaccine use once one is given the green light could provide a way to end the coronavirus pandemic. USA TODAY interviewed FDA Commissioner Stephen Hahn about how the approval process works, how quickly it could go, and how the agency will encourage Americans to take the vaccine.
How a COVID-19 vaccine will be authorized
Question: How will a COVID-19 vaccine get clearance for use?
Answer: Companies have the option of applying for either a license (called a Biologics License Application) or an Emergency Use Authorization. It’s their choice.
Q: What is an Emergency Use Authorization (EUA)?
A: An Emergency Use Authorization is an authority that Congress gave to FDA after the 9/11 terrorist attacks to allow countermeasures, treatments or vaccines to be available earlier than would normally be done under the approval process.
Q: Has the FDA ever issued an Emergency Use Authorization for a vaccine?
A: Yes, for an anthrax vaccine (in 2005).
How an Emergency Use Authorization differs from FDA approval
Q: What standards must companies meet to get Emergency Use Authorization?
A: The standard that’s used for an EUA is that it must be effective in the treatment or prevention of COVID-19 and that the risk/benefit ratio is in favor of authorization.
For vaccines, that’s especially important because unlike treatments, vaccines are given to people who are otherwise healthy. They don’t have COVID-19, so when we look into the risk/benefit ratio … we have to factor that into its safety and effectiveness. We have to be incredibly thoughtful about this.
How FDA evaluates the safety of a vaccine given emergency authorization
Q: What can you say to reassure people that a vaccine approved under an EUA is just as safe and effective as one approved under a BLA, even though there isn’t as much long-term effectiveness data?
A: The standards we expect in safety and effectiveness in an EUA are very similar to what we expect in a BLA. Our career scientists have been doing this for years; this is their area of expertise. They will be judging the science and medicine.
Q: Will COVID-19 vaccines issued under an EUA continue in the licensing process and eventually be fully licensed using a Biologics License Application?
A: Yes. Our expectation is that the sponsors (the vaccine companies) will submit an application, and it’s their call if it’s an EUA or a BLA. Then they would submit, subsequently or in real time, a BLA. We will, of course, prioritize the application for an Emergency Use Authorization, but we will then go through the normal reviews.
How the FDA will encourage people to take the vaccine
Q: What more could be done to encourage people to take an authorized vaccine? Is there anything you can do as head of the FDA to encourage people to get vaccinated?
A: I was a doctor before I became FDA commissioner. If you explain something to a patient – if you share that in a transparent way and then you do what you say you’re going to do – that builds trust. We will follow our process, look at the criteria – we’ll be transparent about those.
Q: Will you get the vaccine yourself? Either in April or May when it may become available to the general public, or do you fit in one of the categories that are likely to have access sooner, such as front-line medical workers?
A: I’ve been clear, I would not allow the agency to authorize or approve a vaccine that I wouldn’t want my own family to get. No one at FDA would want that to occur.
When it’s appropriate for me to get the vaccine, from the guidelines’ point of view, I will get that vaccine. I would strongly urge my family to get it. I have 100% confidence in the staff at FDA. If it would enhance confidence in the vaccine, I would get the vaccine as soon as it is authorized.
Q: An employer or school cannot require someone to get a vaccine issued under an EUA, right?
A: Institutions may require individuals to take an FDA-approved vaccine or apply for an exception. However, EUA products are still considered investigational.
It’s possible that some employers or schools will have questions or concerns about an investigational product issued an Emergency Use Authorization, which is why we will be as transparent as possible about the data and information we use to make our decision. This should help those organizations determine what is most appropriate for them.
How long it will take for a vaccine to be authorized
There are several steps to the vaccine authorization process. First, a company must apply to the FDA. Then, the FDA must go through the application and send it to an outside review board called the Vaccines and Related Biological Products Advisory Committee (VRBPAC). That committee meets on Dec. 10 and will send the FDA its comments and recommendations. Only then can the FDA make a final decision on a vaccine.
Q: How long should we expect FDA to deliberate after it hears from that committee?
A: We expect it to be days, but it’s very dependent on the complexity of the data and the comments we get back from VRBPAC.
Q: So it could be longer?
A: We cannot prejudge our process; our scientists have to make the decision. We will take the time that’s needed to make the right call on this.
We want to move quickly because this is a national emergency, but we will make sure that our scientists take the time they need to make an appropriate decision. It is our job to get this right and make the correct decision regarding vaccine safety and efficacy.
Q: How much paperwork does an EUA involve? In the old days, there was so much paperwork, it came in on wooden pallets. Can you give us a metric?
A: These applications are very complicated. This is thousands of pages of information that our scientists have to go through. … FDA is one of the few, if not the only, regulatory agencies in the world that looks at the raw data in a clinical trial. We refer to it as the line data. We analyze the data, we have expertise in that, we’ve done that for years. This is why it takes us time because it’s very complicated.
That’s another issue that I believe should provide great comfort to the American people: These scientists will do the number crunching. We have biostatisticians, we have scientists. We don’t just accept the conclusion of our sponsors – we will come to our own conclusion.
Q: How many people does the FDA have working on COVID-19 vaccines?
A: We have a review group that is set up and meets regularly. We have hundreds of people in the groups that look at biologicals and products, and for many of them, their time has been allocated to these (vaccine) applications. And we will bring to bear any staff that we need across the agency.
How the FDA will monitor vaccine safety
Q: Does the oversight end once a vaccine is authorized?
A: We will be setting up systems to follow an authorized vaccine’s safety and effectiveness to ensure we have a very robust assessment of safety.
Q: How long will the FDA follow up on these vaccines to see how long they are effective?
A: At a minimum of two years and probably longer.
Q: How much will the public know about the decisions you make regarding vaccines?
A: It’s something that is a lesson learned in the pandemic – increased transparency helps people trust the process. Our expectation is that we will have something written for everyone to see that we will post online. Our intention is to make this understandable and relatable to most Americans.