Dr. Anthony Fauci: The vaccine won't be the end of the story

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), discusses the purpose, development and timeline of COVID-19 vaccines in the United States and Europe.

Video Transcript

ANTHONY FAUCI: And that's the primary endpoint of most of the virus, is to prevent clinical disease. To prevent symptomatic disease. Not necessarily to prevent infection. That's a secondary endpoint. But the primary thing you want to do is that if people get infected, prevent them from getting sick. And if you prevent them from getting sick, you will ultimately prevent them from getting seriously ill.

So that's what we want to do. The first point-- which we call a primary endpoint-- is that. If the vaccine also allows you to prevent initial infection, that would be great. But what I would settle for-- and all of my colleagues would settle for-- is the primary endpoint to prevent clinically recognizable disease. And that's what we hope happens. And if we do, that will go a long way to diffusing this very difficult crisis that we're in.

ANJALEE KHEMLANI: Of course. And going to the point that you've made that the vaccine won't be the end of the story. Definitely mitigation tactics will remain in place for some time. Going onto the trials themselves, it seems like the UK is setting up to do a challenge trial. And while we're already have some vaccines in late stage trials here, it does seem that with a number of candidates out there, there's some room for using this strategy. Is the US setting up to do a challenge trial as well?

ANTHONY FAUCI: You know, we really don't think that that's necessary when you have so many infections. I mean we are having-- in this country as we started the discussion off-- with over 80,000 infections per day. Fundamentally when you do challenge studies are a number of reasons. One of the most important of which is that there's not enough disease activity out there for your vaccine trial to give you a definitive answer.

And even though challenge studies may have a place under certain circumstances, it's not the same as the actual circumstances with which a person gets naturally infected. So although you can get some good information from a challenge trial, the real world information that you want is out in the field when someone is actually being exposed to natural infection, and to determine if the vaccine prevents against that.

So right now, we're not planning any challenge studies because we have so much infection going on. We have five or six vaccines that will be in trial in the midst of these 80,000 per day infection. I think we're going to get enough information that we need to make a decision as to the safety and the efficacy of a vaccine without resorting to a challenge trial.