A new episode of our podcast, “Show Me the Science,” has been posted. At present, these podcast episodes are highlighting research and patient care on the Washington University Medical Campus as our scientists and clinicians confront the COVID-19 pandemic.
It’s possible some people may have been infected earlier, but the first COVID-19 diagnoses in the U.S. occurred in late January. Since then, testing failures, partisan political debates, conspiracy theories and desperate searches for effective treatments have characterized the pandemic response in the United States. However, through all of the noise, scientists have learned quite a bit, according to William G. Powderly, MD, the Larry J. Shapiro Director of the Institute for Public Health and co-director of the Division of Infectious Diseases at Washington University School of Medicine in St. Louis.
Powderly, also the J. William Campbell Professor of Medicine and director of the university’s Institute of Clinical and Translational Sciences, is a veteran of the fight against HIV and AIDS. Many of the lessons learned during that epidemic can be applied to the battle against SARS-CoV-2, he said. But a big problem facing the U.S. in its response to the virus is that so many people seem to want simple answers, and simple answers are highly unlikely, he added. And Powderly said we can expect to live with upheaval from the virus until a vaccine is developed.
The podcast, “Show Me the Science,” is produced by the Office of Medical Public Affairs at Washington University School of Medicine in St. Louis.
Jim Dryden (host): Hello, and welcome to Show Me the Science, a podcast about the research, teaching, and patient care, as well as the students, staff, and faculty at Washington University School of Medicine in St. Louis, Missouri, the Show-Me State. My name is Jim Dryden, and I’m your host this week.
William G. Powderly, MD: Masks work. The problem is not wearing them. Social distancing works. What we have seen in the hospitals since we introduced universal masking and greater social distancing is that we have not had any, in our hospitals across the country outbreaks of COVID and transmission except in situations where people drop their guard.
Dryden: That’s Washington University Infectious Diseases Specialist, William Powderly. Powderly is a physician and a veteran of the HIV crisis of the ’80s and ’90s who now directs Washington University’s Institute for Public Health. He has an update on where things stand now that we’ve been in the midst of the pandemic for almost six months. Powderly says it’s key that some sort of a vaccine be developed if we hope to get back to a world more like the one we left behind last March. Even after six months, Powderly says we’re probably still closer to the start of the COVID pandemic than to its conclusion.
Powderly: We are still in the early phases of this pandemic. The virus has caused a tremendous amount of disruption, but on average, even in the United States, we’re looking at less than 20% of the population has actually been infected with the virus. And if we think about the concept of getting control of this pandemic, we know that we need to get to herd immunity, for want of a better term, whereby 65 to 70 percent of people have been infected. I think the other thing though, however, if you think of it in trying to take stock is that we’ve learned a lot. We aren’t where we were in March. We’ve learned a lot about how we can actually cope with this. We’ve learned a lot in terms of how we can manage people who are infected. We’ve learned a lot about who’s at greatest risk and how we can protect those in a better way. And from a scientific perspective, we’re much more advanced. The pace and acceleration of the scientific advances is quite remarkable.
Dryden: You mentioned the concept of herd immunity and a certain number of people have to get infected. Do those people have to be sick because we’ve also heard that a large number of folks who have infections remain asymptomatic? Would they be counted in the herd immunity? Or do you have to have symptoms in order to get the immunity?
Powderly: So it looks like now that if you’ve been infected with the virus, whether you have symptoms or not, you develop an immune response, and if you develop an immune response then you have immunity. Probably the most important thing that’s uncertain is durability of that immunity. How long is it going to last? It does look like the more symptomatic you are, the more your immune system has a robust response. And that means that, at least in theory, you’re likely to have a better and longer-lasting immune response. As I said we’re learning a lot, but we don’t know all the answers. But what I think we’re reasonably confident on now is that any infection, whether it’s symptomatic or asymptomatic, does lead to the probability of somebody being immune to further infection at least for the next six months and quite possibly longer than that. One thing that your question, Jim, raises about asymptomatic infection is, well, does that mean there’s a lot of people out there who are infected and we’re underestimating it? And I think the short answer is no. I mean if you look at New York, there were parts of New York that were devastated, and yet, the penetration of the virus was still only about 30%. Now 30% means that 70% of the people there are still vulnerable. They don’t have an immune response. And if we look at St. Louis as an example of a city that had an outbreak, had significant morbidity with it, our estimate is that it’s less than 10%, and that still makes sense to me that there’s a large and vulnerable population.
Dryden: Now while we’re making all of this progress in terms of understanding and developing therapies–I mean for months now we’ve heard about hand washing, masks, physical social distancing–those still remain the best tools for stopping the spread of the virus at least right now, correct?
Powderly: Absolutely. The first thing to do, to say, is that they work. I mean we have more and more information that it works. It’s not made up. We have very clear objective evidence that masking works. We also have really good stories and anecdotes. To me, one of the really strong sort of narratives was the situation that happened in Springfield, Missouri, with the hairstylists. Two women, clearly infectious, wore masks, their customers wore masks, and 150 exposures, and no cases. Masks work. The problem is not wearing them. Social distancing works. What we have seen in the hospitals since we’ve introduced universal masking, greater social distancing is that we have not had in our hospitals across the country outbreaks of COVID and transmission, except in situations where people drop their guard. And the usual situation that was is taking a break. Taking a break, taking off your mask, sitting and having a cup of coffee with colleagues and forgetting about the social distancing. And we’ve had outbreaks here and elsewhere in the country, but even in an environment where we know there’s a lot of infection because we have patients in the hospital with infections, we have not seen major problems since we have really emphasized the need to wear masks, the need to have social distancing, and the need to constantly look after hand hygiene.
Dryden: Now back when things were first beginning to close down in the spring when the schools were closing and sports leagues were canceling games and bars and restaurants shut down, businesses asked employees to stay at home, the rates of infection, serious illness, and death they were lower then than they are now at least around the country. I mean in New York obviously, they’re in better shape now than they were then but in a place like St. Louis we have higher rates now but we’re continuing to reopen or to stay open. And I wonder where we go from here.
Powderly: The first thing is that if you look at St. Louis now, and St. Louis as an example, we’re seeing many more infections but we’re actually not seeing the increase in hospitalizations and death, and that is because there’s been a very significant shift in the demographics. And what you’re seeing is that more young people are becoming infected. So there’s a greater number of cases in the community, and our community rates are actually very high and worryingly high, but that has not yet translated to hospitalizations and death. And I think a fundamental reason for that is that the experience in April and May showed us as a community and older members of the community how vulnerable they were. So we’re doing a much better job of protecting people in nursing homes. At one point, in the first part of the epidemic, nearly half of the cases that we were seeing in the hospital were coming from nursing homes. Now it’s less than 10%. That’s the first thing.
The second thing is I think whereas, we’re seeing all the community spread, I think what you’re seeing sociologically is that older people who perceive themselves to be at greater risk are looking after themselves. They’re less likely to go out. They’re less likely to go to restaurants. They’re much more likely to wear masks. And that’s human nature. I mean if you think you’re at a greater risk, you’re going to try to minimize your own personal risk. That’s another reason why we have not had the rise in hospitalizations and deaths that we saw in the beginning of this epidemic. The one thing it does mean is that the economic effects are going to be sustained because obviously, those people who are staying indoors and looking after themselves are not going out spending money, and that won’t change that much.
I think the other part of it is when can people go back to work? When can you resume things safely? And unfortunately, politics has really interfered with common sense and public health in this regard. I think there was a naive assumption that if we just went back to work the economy would rebound. But people don’t behave like that. People are concerned about their own personal health and their own personal risk. And just because somebody says we should all go back to work doesn’t mean we’re all going to do it. I think that’s exactly what has happened. We’re having a debate right now about going back to school and going back to college and so forth. And the one thing I would say is that unfortunately, and it’s a feature I think that’s common in this country and other societies, is everybody wants a simple answer, and it isn’t a simple question. So you aren’t going to get a simple answer. The safety of doing that and the right way to do it is going to be completely dependent on things like, “What is the prevalence at the moment in the community?” Bringing people back into congregated settings, whether you’re talking about workplaces, whether you’re talking about schools or colleges, in the middle of a rising epidemic is a recipe for disaster. One of the things that people talk about, for example, is we should do mass testing. Well, mass testing is pretty useless if the turnaround time for any results is a week because it’s too late.
Dryden: Yeah. And I was going to ask about that because testing has seemed–I mean that’s been the thing that we keep coming back to ever since March. And I’m wondering if any cheap, rapid tests might be available anytime soon. I think, for example, of a pregnancy test that could be used at home; if you get a positive, then you go to the doctor for a confirmatory test. Is anything like that on the horizon where people could test themselves at home before they leave for work? And it’s not maybe as sensitive and specific as we would like from a confirmatory test in a doctor’s office, but it’s something.
Powderly: You’re absolutely right. That’s the holy grail of testing is to have something that is widely available, gives a rapid answer, and is relatively inexpensive. And there are a number of strategies that people are looking at. I’m aware of saliva-based testing where people do this at home. I’m aware of at least one group that’s looking at a breathalyzer approach. Hopefully, we’ll have something by the fall, but we’re not quite ready for prime time yet.
Dryden: Is there something about this particular virus that worries you the most?
Powderly: The thing that worries me the most at the moment is whether we will have a vaccine because we need a vaccine. I think, as viruses go, we may be lucky with this one. So, for example, it doesn’t appear as if it has a lot of mutations or the ability to mutate rapidly. If it had the mutation ability of HIV or even influenza, we could be dealing with a situation where we’d never get an effective control or effective vaccine. The hard thing about it from an antiviral perspective is that it’s capricious. So who do you treat? If you wanted to treat someone early in the infection, you’d have to treat everybody because right now we don’t know who is going to get sick. We know demographically who is going to get sick–if you’re older or if you have underlying illness–but we don’t know with any degree of certainty. And the pace of it means that if an antiviral is going to work, it has to be given early. So a vaccine becomes the most important thing. And yes, there are quite a number of vaccine candidates and the amount of attention and the amount of investment is huge, but all of the vaccine strategies that are being used are novel. They haven’t led to a successful vaccine in the past, so from a scientific perspective what you’re doing is you’re going into uncharted territory. They all make sense. They all have the potential to be effective, but those of us who’ve been doing clinical research for a long time know that there’s a lot of difference between what is an early phase one or animal study and what is actually ultimately safe and effective in humans. And my biggest worry is that we will get it wrong.
Dryden: Several years ago you were on the front lines during the HIV/AIDS crisis, and that’s an infection that’s basically under control here in the United States now. I’m not sure if you could say the same thing in some parts of Africa, but it’s better there, and we still don’t have a vaccine. Is it possible that there won’t be a vaccine for this, but as with HIV, some sort of antiviral therapies might help?
Powderly: Yeah, you’re absolutely right. We could get to a stage where the virus has penetrated enough that most people are immune naturally and that we have effective antiviral drugs for the small proportion of people who get really sick and don’t have natural immunity. The one thing I would–and I don’t want to be overly pessimistic–is that yes, we have very effective antiviral therapies for HIV. It did take us 14 years to get there. Now virology as a science has changed as a result of HIV, and the technology and the understanding has moved on enormously in the 25 years since we developed antiviral therapies. The other point to remind people is that we have very effective treatment for HIV and we still have 20,000 deaths a year from AIDS in the United States. Just because we have effective treatment doesn’t mean that this virus will disappear; it’ll just become controllable and manageable like other infections, like other diseases. That’s better than where we are right now. And I don’t want to diminish that as a target, but if we truly want to get elimination and make it more like measles, mumps, and things like that, we need a vaccine.
Dryden: I have one more question. Here at St. Louis we’ve seen this with our baseball team just how quickly the virus can spread, how hard it is to contain when people are in close quarters. We assume that most of those baseball players are going to recover but we also hear about a lot of people who have symptoms or maybe even don’t have symptoms who develop long-term problems: heart damage, lung damage, problems in other organ systems. Do we know what proportion of people who get better actually have those types of long-term effects?
Powderly: No, we don’t really yet. And that’s a really important question. I mean there are some emerging studies that are starting to come out that show two or three different types of problems. So one thing that seems to be relatively common is a post-viral fatigue, a little bit like chronic fatigue syndrome that you’ve heard lots about associated with other infections, and that appears to be relatively common. And then there are reports of people who have heart problems, neurological problems. The frequency is unclear yet. And nobody has yet done that sort of, the proper type of study that says, “I’m going to take a whole group of people who I know when they got infected and I know what their symptoms were, and I’m going to follow them longitudinally and see what proportion have heart defects, kidney defects.” So right now, it’s mainly case reports and anecdotes, but it’s in an increasingly accumulating body of evidence that this virus does have long-term sequelae and that the long-term health effects of this virus may take us many years to figure out.
To give you an example, we very clearly know that there’s an acute effect and an acute mortality, but we’re not going to know for quite some time if you have somebody with diabetes and preexisting heart disease who recovers from COVID, would that accelerate their heart disease and diabetes over the next 10 years? So in other words, would they lose 10 years of their expected life as a result of having had COVID? Only time will tell us the answers to those questions. That’s why when I hear people say, “Oh, it’s trivial. I don’t mind if I got infected,” and you’re 20 or 25 years of age. One, you might get a severe infection, but more importantly, you don’t know if this is going to be the equivalent to smoking 40 cigarettes a day for 20 years. In other words, it may have an effect when you’re 50. And when you’re 20 you may not care about that, but when you’re 49 you will.
Dryden: Powderly says researchers at Washington University School of Medicine in St. Louis are involved in dozens of studies of therapies, vaccines, and of the long-term impact of COVID-19 on those who do become infected. Meanwhile, Powderly says we need to rely on many of the same things we’ve known pretty much since the start of the outbreak: Wear a mask, stay out of big groups, leave space between yourself and others, and keep washing your hands.
Show Me the Science is a production of the Office of Medical Public Affairs at Washington University School of Medicine in St. Louis. The goal of this project is to keep you informed and maybe teach you some things that will give you hope. Thank you for tuning in. I’m Jim Dryden. Stay safe.