Q&A: Health policy expert Mark McClellan on the pandemic

Mark McClellan is the founding director of the Duke-Margolis Center for Health Policy and former commissioner of the Food and Drug Administration

What does the fall season look like with the coronavirus? 

I’m cautiously optimistic. That said, we need to prepare for a potential additional wave. That’s been the feature of previous pandemics, and there also are a lot of reasons to think there could be a bigger surge in cases in the fall, with the return to school, with changes in the weather, and with outbreaks that are still very active in other parts of the world. We are reopening in the U.S., and we’re definitely seeing outbreaks associated with reopening.

How does this novel coronavirus differ from SARS and MERS, two earlier pathogens? 

They are very different. I was FDA commissioner during the SARS outbreak. We did see significant outbreaks in places like Singapore, Hong Kong, and Taiwan; as a result of that experience, they built much stronger public-health surveillance systems to prevent future outbreaks. The SARS outbreak was contained essentially because it did not spread so easily. While the cases of SARS and MERS tended to be more severe, the number of cases and the transmissibility makes COVID-19 much more challenging to manage.

Is it likely that the virus might have been around for a long time without conspicuously infecting humans? 

The virus probably was around in the animal community for some time. Genetic testing and studies of animal populations in China, where we think the virus arose, will help address that question. We also are getting very good at doing genetic tests of the different viral variants that are present in different places around the world, which can help us understand how the virus actually spreads. In the western U.S., it looks like the spread from China was initially important. In the eastern U.S., it spread from Europe with slightly different genetic variants. I don’t think that’s a reason to worry, by the way, that the virus is mutating so that it won’t respond to that potentially effective vaccine or other treatments. 

Will we ever know whether people are protected from the coronavirus after having been infected by it? 

I hope so. What you need to do is identify a whole population of people who have been exposed to the virus and have recovered and measure their antibody levels—that’s the serology test—and then track those antibody levels over time. And then what you’d really like to know is not just what the antibody levels are, but is there any evidence that those individuals either get reinfected or could potentially transmit the virus again? That means doing that other kind of test, the diagnostic test for whether you’ve got an active viral infection, on those same individuals over time. If it’s like other coronaviruses, at least for people who had a significant infection and mounted a significant response, the response should be present for a while, maybe not years, but at least long enough to get through this vaccine season. It does look like, from other coronaviruses, that some of that immunity should persist for a while. 

Why is it that some people cope easily with the disease and may not ever know they have it, while others develop severe inflammation, lung damage, and so forth? 

This is still a relatively new and not-well-understood virus. It does appear that one of the factors in the intensity of the response is not the virus itself but the body’s immune reaction to the virus. It looks like blood type matters, that men apparently do worse than women, and that immune response is an important factor. 

Are you at all concerned that the race to develop the vaccine, or a whole bunch of vaccines, might be proceeding too quickly, at the risk of insufficiently ensuring safety or effectiveness? 

The typical process for a vaccine is a long and uncertain and linear process. There’s preclinical development, then clinical testing, and after that, review and manufacturing. It all can take many years. The public-health impact and the economic impact of COVID-19 is way bigger than any infectious disease that we’ve seen in a long time. That means there are a whole lot more resources being devoted to developing vaccines. Second, on the biomedical side, we’ve got a wider array of platforms that potentially could produce effective vaccines than ever before. For example, vaccine platforms that are based on viruses that we know don’t cause adverse health consequences for people but that cause individuals to mount an immune response. So what’s happening is that long linear process is becoming a parallel process, with clinical testing and manufacturing going on at the same time for lots of vaccine candidates. We still need to do the large clinical trials with lots of people, because these are vaccines that are going to be given to millions if not billions of relatively healthy individuals. We need to make sure that there aren’t important safety side effects, as, unfortunately, has happened in a number of vaccines that ultimately didn’t make it to market. And we need to make sure that the vaccines really are effective. They may not be fully effective, but at least as good as a flu shot. That takes significant clinical testing, too. There also is a lot of investment in manufacturing hundreds of millions or billions of doses before we even know whether these vaccines work or not. We may end up having to throw those away. But the main goal is to make sure there is no delay between finishing the clinical tests—which for some of these vaccines will be done by later this year—and then having a significant supply of vaccines available for use. 

Has the coronavirus revealed health disparities, exacerbated health disparities, or both? 

We already knew we had big health disparities in this country, and the COVID-19 crisis is exacerbating them. And it’s because of reasons that we ought to be able to address, like people working in jobs where they have a high risk of exposure. It’s because of differences in access to early diagnosis, testing, and treatment that could potentially help prevent spreads and at least support people if they have very serious cases. For lower-income individuals, for Blacks, for Native Americans, we’re seeing very big disparities, both in the rate of cases and in the outcomes when cases occur. This is a big challenge for the country to respond to the pandemic, but my hope is that our response will get at these underlying health disparities.

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