Amid Confusion About Reopening, An Expert Explains How To Assess COVID-19 Risk

TERRY GROSS, HOST:

This is FRESH AIR. I'm Terry Gross. We're in a new and confusing stage of the pandemic. More cities are opening. The numbers have gone down in some regions and are going up in others. As cities do open, many Americans are confronted with difficult decisions about how to safely return to work and which other activities feel safe and which aren't worth the risk.

With me to talk about those issues and more is Michael Osterholm, one of the nation's top experts in infectious diseases. He's warned for years that a pandemic was likely to happen and that we'd better start preparing. Osterholm is the founder and director of the Center for Infectious Disease Research And Policy at the University of Minnesota, where he is a professor of public health. From 1975 to '99, he served in various roles at the Minnesota Department of Health, including a state epidemiologist. He's led investigations of outbreaks including foodborne diseases, toxic shock syndrome, hepatitis B in health care settings and HIV in health care workers. Osterholm is the author of the book "Deadliest Enemy: Our War Against Killer Germs," which has just been published in a new edition with a new foreword about COVID-19.

Michael Osterholm, welcome to FRESH AIR. Let's talk about where are we now, what patterns we're seeing in places where cases are going up and others where cases are going down. What's the larger pattern?

MICHAEL OSTERHOLM: I, as an epidemiologist, would always like to come on and share with you definitive information about this is where it's going, this is what's happening, this is what we can expect. And I must say, since the very first day of this pandemic, I don't think we're in a more confused position about what's happening.

In the United States, we have 21 states where we see cases increasing, some of them quite dramatically. In 21 states - in addition to that, we have cases decreasing, and nine right in the middle where it's just level. And we can't tie this to necessarily reopening the economy. The states where we're seeing cases decrease have also had reopenings (ph). And so I think it's - the virus is doing what it's doing right now. And we just aren't quite sure what it's going to do next.

GROSS: Are there different strains of the virus in different parts of the country that might account for otherwise inexplicable reasons for rates going up or down?

OSTERHOLM: We don't have any evidence the strains are playing any kind of a role. But if we do take a step back and look at the influenza model - in other words, does that tell us anything about what might be happening here, realizing this is a coronavirus and not influenza? We have never understood why, in previous influenza pandemics - and there have been 10 of them in the last 250 years - do you see cases occur in the first several months of what we call a first wave. And a wave being defined by peaks of cases and then literally a trough where cases, in a sense, almost disappear. We've seen that in all the previous influenza pandemics. That disappearance may last for two or three months and then we see a big second peak. We have no idea why the first peak occurred. We have no idea why they go away. We have no idea why it comes back. And then a second wave ends, too.

And so there's something surely in the biology of these viruses that's causing that to happen. Is that what's happening right now with the coronavirus? We don't know. It's very clear that there's extremely high levels of transmission occurring in parts of the United States right now. Why we don't see it others? And I don't know if that means that this is going to act more like an influenza virus in terms of how it spreads and what we might expect for cases and the population.

GROSS: I think I hear you saying even if you're in a place where the cases are going down, that's not necessarily a sign of the future. They might go back up again, and not even necessarily because of behavior in that region but just because of the behavior of the virus.

OSTERHOLM: Exactly. It's clear and compelling that human behavior is important in transmitting the virus. And we saw that very early in the United States as well as in Asia and Europe, where we had these very hot outbreaks that developed. Whereby doing the kind of physical distancing that we did, we're quite certain that we were able to shave cases off the big peak that might have occurred. But in terms whether the virus is eliminated out of an area, if it stays out of an area, that may only be in part due to human behavior, so we surely don't want to stop emphasizing the importance of the distancing.

But as we also now understand from using an influenza like model, if cases should disappear over the course of the next six to eight weeks, or at least be greatly reduced, that is not necessarily good news. It surely seems counterintuitive that we would want cases to happen. I don't want anybody to get sick, severely ill or die. But if we saw a trough of cases in the next two months, I think that would really tell us that we're likely to have this big second wave much like we would see with influenza, which could be much worse.

I think the one factor that we must keep in mind at all times is is that to date we have about 5% to 7% of the U.S. population has been infected with this virus. That's it. All the pain, suffering, death and economic disruption of occurred with 5% to 7%. But this virus is not going to slow down transmission overall. It may come and go, but it will keep transmitting until we get at least 60% or 70% of the population infected and hopefully develop immunity. Or if we get a vaccine, it can get us there, too. And so I want to be really clear - none of us are suggesting this is going to stop and go away. But if we see these starts and stops of the virus in between times, it just - we don't know quite what's happening.

GROSS: Sixty to 70% of Americans getting the virus - that's a terrifyingly high number.

OSTERHOLM: It is a very sobering number, if nothing else. And, again, as I pointed out, we're in a race right now with the virus. Think of this as kind of viral genetics and physics all combined, where the virus is going to keep with its - the way it gets transmitted, what it does, how it does what it does is all basically driven by that biology. But at the same time, it's going to keep transmitting in the population much like viral gravity. It's just going to keep happening. And our challenge is, can we get a vaccine first to get more people to be immune to this virus than having to develop that immunity as a result of getting infected and either, you know, seriously ill and dying or infected and recovering and for many, hopefully, even a mild illness?

GROSS: You've pointed out that we can't stay closed forever. It would kill the economy. It would kill people's livelihoods. It would kill life as we know it. On the other hand, there are great risks with reopening. What do you see in the near future in terms of, you know, cities opening or closing or going back and forth between the two?

OSTERHOLM: I think, right now, most of the world - not just the United States, but most of the world - is quite confused about what to do or why to do it. And what I mean by that is that, already, I think we've seen pandemic fatigue set in in the United States. You know, right around Memorial Day, the country was ready to say, we're done with this. We're unlocking. You know, we're going to no longer do the kind of physical distancing that's been recommended. We should reopen the economy. You know, let the cards fall where they may.

And I think to myself, wow, that's what's happened after 5% of the population has been infected. How might we ever get a population to do what it needs to do to reduce transmission to hopefully get to that vaccine before the disease gets us to that 60% or 70% level. And I think about that's going to be months and months. This is not - what? - it's going to last for a few more weeks. And if you look at influenza pandemics, that had - they all did last for years, not for just a couple of months. And so I think that that's the challenge we have today is helping people understand it. We've got to figure out how to live with this virus as much as we've had to painfully understand how to die with this virus. And somehow, we have - can't live locked down for 18 months. That - as you said, that will not only kill, you know, the economic issues that we all are concerned about.

But it will also, you know, have the impact on society that will be also quite devastating. At the same time, we can't let this virus just run willy nilly. We're already seeing hospitals today in parts of the United States where they are literally to the top of their ability to handle cases in intensive care units. They're running out of beds. And so somehow we're going to have to figure out, how do we thread the rope through the needle in the middle?

GROSS: If you're just joining us, my guest is Michael Osterholm, founder and director of the Center for Infectious Disease Research and Policy at the University of Minnesota. His book, "Deadliest Enemy: Our War Against Killer Germs," has just been published in a new edition with a new foreword about COVID-19. We'll talk more after a break. This is FRESH AIR.

(SOUNDBITE OF THE ACORN'S "LOW GRAVITY")

GROSS: This is FRESH AIR. We're talking about where we are now in the pandemic with Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. He's led investigations of outbreaks, including food-borne diseases, toxic shock syndrome, Hepatitis B in health care settings and HIV in health care workers. Osterholm is the author of the book "Deadliest Enemy: Our War Against Killer Germs," which has just been published in a new edition with a new foreword about COVID-19.

One of the things we're dealing with now is the politicization of the virus. Some public health officials have resigned because there have been protests around their homes by people protesting mandatory masks. In Florida, a data expert in the health department refused to misreport the number of cases and was fired. She was asked to report a lower number than actually existed.

She says - her name is Rebekah Jones. And she says a superior asked her to open up the data and alter the numbers so that the state's coronavirus positivity rating would change from 18% to 10%. And therefore, the state would look like it met its target to reopen. What are some of the examples you're seeing where the virus has become a political issue instead of a health issue?

OSTERHOLM: We have an extremely divided country today. And to add to that, we, first of all, have the most severe pandemic that the world's experienced since 1918. You know, I think people don't realize the impact this virus has had already. Then you look at the economic implications. And while some will see the economy is recovering right now, you know, I know what's ahead yet. We have some, really, very painful days ahead for the economy. So we haven't seen economic issues like this literally dating back to the Great Depression. We have politicized issues that should never be politicized.

Mask or no mask, you know? That should be about public health. Do they work? Do they not work? How well do they work? But no matter how we try to put that message out there, we find that people will accept it for the way they view it. And I personally, you know, have (laughter) experiences that have not been pleasant with people that think that, somehow, I'm part of a deep state perpetrating this pandemic on the United States from China for purposes that have something to do with politics. And, you know, there's no getting around it with these people. This is what they believe.

GROSS: Tell me more about the pushback you're getting from...

OSTERHOLM: Oh, you should see the emails I get (laughter). I refer emails on, with some regularity, to the University of Minnesota police department just because the threatening nature of them. And I'm not - I'm just one of many that are getting similar kinds of emails. And it's people who believe that, you know, this has been a conscious effort to destroy the economy, to somehow reflect negatively on this administration.

They believe it to be all made up, that none of this is true. And so I think that it's not about science and reason, and at a time when we should all be trying to come together - all of us fighting this virus. And yet, right now, this has become almost the seed of, really, what I would call painful, painful accusations and beliefs that somehow, you know, this isn't really about a public health problem. This is about a partisan issue.

GROSS: Have you ever seen anything like this before, where a virus has become a partisan issue and where people like you are getting threats?

OSTERHOLM: You know, I can't say that it's ever been like this. During the early days of HIV/AIDS, there surely were challenges that occurred. And, you know, when we look back on that, some of that was very legitimate - members of the gay community who, you know, were reflecting on what was happening and not happening by governments. And I think, you know, fortunately, some of the gay activists made governments have to get a lot better, and they did at those. This one is different, though.

This one, as much as it - there are disagreements. And there - you can say that there's unscientific uncertainty. This is one where it's almost as if, somehow, someone has made up a story upon which now to fit the narrative. Meaning that they made the story up first. And, OK, well, let's figure out how this virus fits into that story. And that story is that this is not true, that all these efforts have been undertaken with alternative purposes in mind, not to really stop the transmission of the virus and that people are intentionally not being truthful in government or in public health. And I think it fits in with almost the anti-science movement. It fits in with a lot of areas that we have to deal with in terms of public health today.

GROSS: It fits in with the anti-vax movement, too?

OSTERHOLM: Yes. In fact, we have data that has been obtained over the course of the past few weeks suggesting that there may be as high as 30% of U.S. citizens that would refuse to take an effective COVID-19 vaccine should one be developed because of the anti-vaccine viewpoint.

GROSS: Are there other ways that you've seen the virus become a political issue to the detriment of public health?

OSTERHOLM: Well, I wouldn't call it a political issue. I would call it a lack of government response. And what I mean by that is that we obviously are consumed by COVID-19. And we should be. As I pointed out, we've not seen any infectious disease, virus, bacteria or any other kind of infectious agent cause this kind of severe disease and the number of deaths since 1918. But having said that, this is not our only public health problem. And one of the things I fear greatly is that, a year from now, we're going to be talking about COVID-related deaths in kids around the world, not from COVID, but from the fact that we virtually stopped our immunization programs to try to deal with COVID.

And I think the chances of seeing many more children in this country die from measles than COVID is, really, very, very real. And so it's not so much - it's not a partisan issue at all. It's just the fact that government right now is not functioning well in handling multiple crises at the same time. And so I think that the collateral damage we're going to see out of COVID-19 is going to be substantial with infectious diseases.

GROSS: Are children not getting vaccinated because they're not in school, and they're not going to the doctor because of the pandemic?

OSTERHOLM: Yes, exactly. And in addition, all the public health staff right now are focused, really, on COVID-19 and, you know, contact tracing - that kind of follow-up. And so that we've actually had a real challenge just getting people to be able to work on other areas of public health. This is TB control, HIV/AIDS, maternal and child health, childhood immunizations, safety of water supplies. All these things right now are taking a major backseat.

And I think people had assumed in the public health world, well, maybe this would happen for a few weeks or a few months. Then we could get back to work. As I've pointed out, this has the potential to last for many, many more months. And so what we've got to do is recognize this and say, wait a minute. We have to separate off a part of our public health efforts that are not going to be just dominated by COVID-19, but, in fact, are going to prioritize these other areas because people will die from those areas alone.

One issue that we're very concerned about is antibiotic resistance. We're seeing the use of antibiotics in hospitals associated with COVID treatment to deal with secondary bacterial infections that people pick up in the hospitals. And the amount of antibiotic being used right now is just dramatic. And we know that this is only further fueling the antibiotic resistance problem. Yet, right now, we're virtually not addressing that at all.

GROSS: I'm glad you brought that up because I've been wondering, even at home, so many people are using disinfectants - if they can get their hands on any - to disinfect countertops and other surfaces. And that, too, I think, will contribute to resistant bacteria.

OSTERHOLM: Yes. And one of the challenges we have with this disease, first of all, is making sure that we really have accurate and, I guess, actionable information for the public. I mean, the public right now is so confused about what is safe and what's not safe. And one of the challenges has been is this idea that surfaces play a major role in transmission. You know, and we've looked very carefully at the data dating back for decades and research about these kinds of respiratory transmitted infections. And, clearly, the surfaces play a very, very little role at all in transmission of this.

And so I think we've gone way overboard relative to the disinfection and so forth. And we've made people feel very nervous about just, you know, opening a package, that type of thing. And I think that's been unfortunate. I mean, this is really all about air, breathing someone else's air where the virus is present. It's much, much, much less about environmental contamination. So you know, I would not tell people not to wash their hands because I deal with a lot of the diseases where handwashing is very, very important. But I would also say, no one needs to be frightened of their physical environment with this virus. It's the air they're breathing. And so if that gives people relief, I hope that's helpful.

GROSS: Oh, I think that would give people a lot of relief. So you're saying, like, your mail and your packages, like, don't worry about it? If you're still...

OSTERHOLM: I don't worry at all.

GROSS: If you're still subscribing to newsprint newspapers or print magazines, don't worry about that?

OSTERHOLM: I don't worry about food. I don't worry about newsprint. I don't worry about packages I get here. I don't worry about doorknobs and railings any more than I would during the regular cold season. You know, it's not that that's what's going to be the major challenge with this virus. Over and over again, it's the air that we share with each other that is critical. That's why distancing is so important.

GROSS: We have to take a short break here. So let's do that. And when we come back, we'll talk about some of the practical concerns people have about how to protect themselves. If you're just joining us, my guest is Michael Osterholm, founder and director of the Center for Infectious Disease Research and Policy at the University of Minnesota. His book, "Deadliest Enemy: Our War Against Killer Germs," has just been published in a new edition with a new foreword about COVID-19. We'll be right back. I'm Terry Gross. And this is FRESH AIR.

(SOUNDBITE OF HAROLD LOPEZ-NUSSA'S "HIALEAH")

GROSS: This is FRESH AIR. I'm Terry Gross. Let's get back to my interview with Michael Osterholm about where we are now in the pandemic. He's the director of the Center for Infectious Disease Research and Policy at the University of Minnesota. When he worked in the Minnesota Department of Health, he served as the state epidemiologist. His book "Deadliest Enemy: Our War Against Killer Germs" has just been published in a new edition with a new foreword about COVID-19.

I want to talk with you about the protests. The protests against systemic racial injustice in policing - those protests appear to have been, like, pretty effective in focusing the country's attention on systemic racism and in pushing many cities to make changes in policing and to think about future changes in policing. There's also the issue of the health of the protesters. What are your thoughts about if the protesters are vulnerable to COVID-19 even if they're wearing a mask and were surrounded by people with masks? What is the level of vulnerability in a situation at a really large protest?

OSTERHOLM: As we're recording this on Tuesday, almost two weeks out from when the protests begin, which is important because we would expect to see cases start to develop within that first five to seven days after exposure and really present to medical care in the next five to seven days so about this time. And I can say we haven't seen any major increase at all in cases in any of the cities around the United States that might be associated with protesting. When it first occurred and we were watching it on our televisions or being part of the protests themselves, it was clear that we were seeing all these people together for what had just been several months of hardly anyone together.

And so the challenge of - would this virus to be transmitted in that environment? - was surely front and center for everyone in public health. Now when we looked at that, we realized that it was outdoors largely which, in that case, the virus dissipates quite quickly into the air. If there's any air movements around, it literally blows the cloud away - in a sense, disintegrates it. And so that would mean a lot less exposure to someone breathing the air near someone else who might be infected. On the other hand, there was risk - there were risk factors that we were concerned about, such as people who were exposed to tear gas and smoke that were coughing substantially, people yelling, shouting, whether they had a mask on or not, which we know can aerosolize the virus. You'd be getting it in terms of the air coming out of that voice.

And then on top of that, we had individuals who were arrested put in holding vehicles, sometimes for several hours before they were transported to the local jails. And they are then processed and put in a jail cell overnight. All of that would have likely increased cases. But as I said, we just haven't seen it yet. I think we're probably one to two weeks away from having more definitive answers, whether it was really an increase or not. And I think right now we are hopeful that we won't see a big increase in many of the cities that experienced these large crowds coming together.

GROSS: The protests were outside. Trump has a rally planned for Tulsa in a stadium that holds 19,000 people. My understanding is that he'd like to see that stadium filled. Trump has not been wearing a mask, and I think he doesn't expect his followers to wear masks. To go to this rally, you have to sign a liability disclaimer saying that you won't hold the campaign or the venue responsible if you get sick. What is your reaction to the president of the United States, in a time when all public health officials are saying, you know, keep out of crowds if you can; wear a mask at all times - what do you think about this, like, stadium campaign event?

OSTERHOLM: Well, right now we have to understand that the single greatest risk factor we have for transmitting this virus is largely indoor air where we're in large crowds where we are sharing that air with the people right around us. Any activity that increases that, such as loud voices, shouting, singing - that we all know can enhance the virus being aerosolized or basically put into the air.

So I would just say across the board, without regard to political party or why the event occurred, they shouldn't be occurring if we're trying to reduce the risk of infectious disease transmission with this virus. It's just simply the last thing you'd want to do. It's almost like putting potential gasoline on a fire. So I think it's just fair to say that this should be a universal recommendation across the board that these kinds of events be avoided.

GROSS: And there's the issue if you have thousands of people in a stadium and then they go out - and say each person who's infected infects one other person, then that could be a lot of people. I'm not saying all 19,000 people would get infected. But still - I mean, it's not just the people in the stadium who are vulnerable. It's the people who get the disease who are in the stadium and then go out and infect other people, too.

OSTERHOLM: Yes, this disease really has taken on a level of personal responsibility that I don't think most people understand. And what I mean by that is that, to date, we've had well over 680 health care workers in this country who have become infected and died. Of that group, we estimate that at least two-thirds likely acquired their infections at work, meaning it was not something in the community that got them infected. Now, when you think about that, that's over 400 health care workers who have died trying to provide care to people who, you know, many of them had no reason to think that they might have been exposed to a virus. They weren't in public spaces that would enhance transmission. But they were somewhere breathing air that someone else, you know, was infected with the virus and put that virus in that air.

Well, you can say that, you know, they are, in a sense, putting health care workers at risk when they get infected. And we have to understand that it's just not us. It's - I may say, oh, I'll take responsibility for my own life. But they don't realize what they're doing to others. And so when you intentionally put yourself into harm's way, I almost want to say to them - would you please just sign a waiver, too, that says you won't seek health care at the point when you're severely ill because you may very well also expose health care workers in their attempt to save your life? And that would be really, you know - again, how can you do that?

That, I know, is controversial. But it's one of those things where I hope it would drive home to people that we do have personal responsibility - it's like driving. You know, it's one thing that I might do something to myself if I'm driving drunk driving home. It's another thing if I crash into someone else and cause them great harm. And I think in some ways we have to start holding people more publicly accountable for intentionally putting themselves in harm's way. I don't believe for a minute that such a waiver would be signed by anyone, but at the same time, it should make people think about this. You know, you're not just putting yourself in harm's way. You may want to assume that responsibility, but you're also putting others in harm's way.

GROSS: The New York Times got hold of a tape of Mike Pence talking with governors in which Pence played down new outbreaks. He told governors to stress the magnitude of the increase in testing and to say that that's why some of the numbers were going up. And he said the virus spread was now well contained and that we can quickly snuff out any embers. Is that true?

OSTERHOLM: You know, this virus will not follow public rhetoric or public policy. It's going to follow basically, as I said earlier, kind of the issue of viral gravity. It's going to do what it's going to do. No amount of wishful thinking is going to change this. And, you know, I think at this point, the only responsible position we can take is to understand that we have many more months ahead of us and much more severe months in terms of transmission.

You know, I have always experienced a public that was willing to take the worst of news if you didn't surprise them, if you were just honest and told them what was coming. Where I have seen the public react in a very negative way is when they felt like they haven't been told the truth and then suddenly the truth becomes exposed. In this case, the virus will expose the truth of what's happening. You know, you can't disagree with a virus if it's putting you in an intensive care unit. You're going to go there. And so I think that one of the challenges we have right now is, how do we convey to the public what's yet ahead of us and not try to over reassure them because that is the perfect position to lose all credibility for the future. And I think that's - we're losing that opportunity right now to have credibility for the future with that kind of rhetoric.

GROSS: Well let me reintroduce you here. If you're just joining us, my guest is Michael Osterholm, founder and director of the Center for Infectious Disease Research and Policy at the University of Minnesota. His book, "Deadliest Enemy: Our War Against Killer Germs," has just been published in a new edition with a new foreword about COVID-19. We'll talk more after a break. This is FRESH AIR.

(SOUNDBITE OF ANTONY AND THE JOHNSONS' "CRIPPLE AND THE STARFISH")

GROSS: This is FRESH AIR. We're talking about where we are now in the pandemic with Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. He's led investigations of outbreaks, including foodborne diseases, toxic shock syndrome, hepatitis B in health care settings and HIV in health care workers. Osterholm is the author of the book "Deadliest Enemy: Our War Against Killer Germs," which has just been published in a new edition with a new forward about COVID-19.

Let's get to some practical questions. Now that cities are opening, I think we all could really use some practical advice. Let's start with getting to work, say, carpooling or taking a car service like an Uber. If you're in that situation, is it helpful to open the windows so that there's more air circulating and you're not just breathing the other person's air in an enclosed environment?

OSTERHOLM: Anytime you can, increase airflow in whatever setting you're in. For example, outdoors has its own natural, in a sense, air conditioning. You know, I often hear people talking about the risk of going to the beach, and ironically beaches are probably some of the safest places to go to if you're not literally cheek and jowl with someone just because the wind is blowing all the time, and it's creating, in a sense, kind of a cleansing of the air where that virus might come out. If you're in a building where the heating, ventilation and cooling system is not moving air very frequently, then that aerosol that that person's breathing in that conference room is going to build up over time. And so yes, you are going to be at greater risk in that kind of a setting.

Now in transportation, if you can open a car window, that surely is going to increase the amount of virus movement out. And one of the projects that we're working on right now with a group of international experts is really attempting to measure the exposure that someone likely will have in a public setting, meaning exposure in terms of time and dose. And, you know, I think people often think of transmission with this virus almost like tag. You know, I get close to somebody who's infected, tag, you're now it. It's not at all. It is time related.

We're working on this, and it may be that you need, you know, many minutes to be in an environment where this virus is in the air and you need to inhale it in and, you know, the amount of breathing that you do at a certain level before you get infected. It's not just a yes or no. It's a threshold. And so one of the things we're trying to do over the course of the next month is put out a series of documents that will actually give people just that kind of quantification you're asking for. If I open a car window, do I reduce my risk by fivefold? Tenfold? What is my risk at that point? What's my risk if I'm with 50 people versus 10 people? You know, what's the chances of me actually coming in contact with that virus? We need this information badly, and this is one area where I wish the federal government had done much more to help supply that. In past public health situations, they did do that. And unfortunately, we're not seeing that with the same level of assistance right now as we have in the past.

GROSS: Let's talk about ventilation in buildings, ventilation in an office building or even an apartment building. Is the ventilation system spreading the virus, or is the circulation of air defeating the virus?

OSTERHOLM: Well, you know, there's an old phrase in the environmental movement about, you know, the solution to pollution is dilution. And actually in infectious diseases, the same thing is true. The more you can move air, dissipate these virus - particularly these aerosols, these little fine particles. When you and I talk, we fill a room full of aerosols. If you actually had a special camera that does exist, and you can do this, you can actually see aerosols fill the room and these little particles after just a few - 20 or 30 minutes of talking. So anything that moves air and moves that out more quickly is surely helpful.

The HVAC systems won't spread the virus as such if they have appropriate exhaust, meaning it's largely going outside. Now, if you're in a cruise ship where you don't have that ability, that the air that's in the inner cabins is kind of more or less being swapped out with other air in the inner cabins, that's the challenge. You - what do you do about that? In the case, however, in a large building, in most cases you can exhaust the air out. There is opportunities to do that. Of course, the challenge has always been energy conservation and trying to, you know, make sure that we don't unnecessarily put our cold air out in the summertime when we want to keep it in the building or our warm air out into the outside in the wintertime when we want to keep it in. But so what you have to do is adjust the amount of exchange that occurs, what comes in, what goes out. But the HVAC systems themselves are not going to spread the virus, particularly with exhaust to the outside.

GROSS: Well, let me reintroduce you here. If you're just joining us, my guest is Michael Osterholm, founder and director of the Center for Infectious Disease Research and Policy at the University of Minnesota. His book, "Deadliest Enemy: Our War Against Killer Germs," has just been published in a new edition with a new forward about COVID-19. We'll talk more after we take a short break. This is FRESH AIR.

(SOUNDBITE OF STEFON HARRIS AND BLACKOUT'S "UNTIL")

GROSS: This is FRESH AIR. We're talking about where we are now in the pandemic with Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.

So here's a question. If you are sharing the bed with somebody - husband, wife, boyfriend, girlfriend - and your partner gets COVID, everybody says, well, you should start sleeping in a different room. Not everybody has a different room to sleep in. But even if you do, like, if you've already been breathing the same air in the same bed for several nights during the period when the other person had the infection but just not the symptoms yet, does it make a difference if you separate? Is it already too late?

OSTERHOLM: You know, we don't know. We know that you're more likely to be more highly infectious in that period just before you become clinically ill or into those very first days. I would suggest that most people, even in their first day or two of illness, don't know that they have COVID-19 unless they're able to get in and get tested right at the first symptom and the results come back the next day.

So you're absolutely right. You know, in a sense you've already been pretty much hit by the virus in that close setting. Will more virus transmission to you change your outcome? It's unlikely. And so from that perspective, I think, you know, we recommend people to, you know, separate themselves with the idea that if you haven't transmitted it already, then at least we'll keep you from doing it now. I think the vast majority of transmission is going to have occurred in those first days. And so I am much less of the mind that you need to, at that point, separate and isolate for public health reasons.

GROSS: Let's talk about the antibody test. What do we know about its effectiveness, its false positives or false negatives? And should people be getting it if they suspect that they've had COVID-19? If they had, like, a bad cold or whatever during the winter before tests were available, before we even knew about COVID-19, should they get the test to see, like, maybe that really was COVID-19?

OSTERHOLM: If we had an ideal antibody test today I would say sure, go get it to find out if you had it. But we don't have an ideal antibody test at all today. What we have largely is the wild, Wild West of testing. The FDA has, I think, done a miserable job of overseeing the regulation and the authorization of antibody tests. Today there's over 100 of them in the United States where somebody has just filed with the FDA that they are going to offer this, and that's all they had to do to be able to do it.

We have seen a number of these tests that provide very, very poor results. Even a relatively good test under the conditions of how frequently this antibody might occur in the population, meaning that 5% have already been infected, if I were to test a large segment of a population today, half of all the test results that came back positive would actually be false positives, meaning they didn't really have the antibody. So we have discouraged the use of these tests unless it's for research purposes, unless you're trying to identify someone where you're trying to find out, do they have antibodies? So they might enroll in one of these studies where we're trying to harvest antibodies from people who've already had infection. But I would not use it at this point as a way of telling an individual patient that they did or didn't have COVID.

The final piece is, of course, we don't know what antibody really means in terms your own protection. We're worried that we're going to start seeing people take different approaches to how they protect themselves if they think they're antibody-positive. And while we suspect that this antibody does provide some protection from getting another infection, we surely know from SARS and MERS that's not universal. And so at this point, I can't even tell somebody, if you really do have the antibody, are you protected or not from getting it again.

GROSS: You are the high-risk category because you're in your 60s. How are you living your life knowing that this is a long-term issue - it's not something that's going to go away right away?

OSTERHOLM: You know, this has been one of the hardest parts of this entire pandemic for me. I have two wonderful adult children who don't live that far from me, and I have five incredible grandchildren. I've not seen them since March 10. This has been so hard. You know, I see them on FaceTime. You know, I get to do all those kinds of things with Zoom and so forth, but it's not the same. So it is very hard.

And you know, I'm trying to understand in my own life, what can I accept or what should I accept as a risk? You know, frankly, my kids and my grandkids are more frightened of being around me from the standpoint of them transmitting to me and - as an older adult male, you know, being at increased risk for a serious disease.

So I think that I don't have any perfect answers yet. I haven't seen my kids and grandkids. I miss them desperately. That's my benchmark right now. When I figure out how to do that, I'm happy to provide it free to the world - you know, this is the answer. I don't have an answer right now.

GROSS: Are you going out?

OSTERHOLM: I go out very limited. You know, in fact, I have to say that it really hit home to me the other day that since the first week of March, I've bought one tank of gas for my car. And I still have a lot of it left. That's something if you'd said five months ago that would be something that I would do, I would say, no, come on. And so I think we've all had such a big change in life. I don't go out much at all. When I do go out, I wear my mask. I limit my time in the public setting. It's a hard thing. We haven't been to work at the University of Minnesota at our center together as a group since since early March. It's a whole new world, and it's a challenging world.

And one of the things that really has hit home to me in all of this - I want us to stop using the term social distancing. It's physical distancing. And that's what we should do.

GROSS: Oh, I'm totally with you on that (laughter).

OSTERHOLM: That's what we should do is do physical distancing, but don't socially distance. If there was ever a time when we all need each other, it's now.

GROSS: Yeah.

OSTERHOLM: And so I - yeah. So I do a podcast myself once a week. And at the end of it, I stress the fact that we need to start an epidemic of kindness right now that will take on this pandemic of this virus. And you know, if it was ever a time for us to actually be social, to be reaching out is now. And I hope that if nothing comes out of this show, this message comes out that it's time for us to actually be socially so close.

GROSS: Michael Osterholm, you've been so generous with your time. Thank you so much. I wish you good health. And thank you for looking out for us.

OSTERHOLM: Thank you - and the same to you.

GROSS: Michael Osterholm is the director of the Center for Infectious Disease Research and Policy at the University of Minnesota. His book "Deadliest Enemy: Our War Against Killer Germs" has been published in a new edition with a new foreword about COVID-19.

Tomorrow on FRESH AIR, my guest will be Kristen Howerton whose new memoir is about being the mother of two white biological children and two black adopted children. It's taught her a lot about the meaning of white privilege. Her father was a pastor, so was her ex-husband. She left the church over issues like women's equality, LGBTQ rights and politics. Her new memoir is called "Rage Against The Minivan." I hope you'll join us.

(SOUNDBITE OF ALLISON MILLER'S "VALLEY OF THE GIANTS")

GROSS: FRESH AIR's executive producer is Danny Miller. Our technical director and engineer is Audrey Bentham with additional engineering from Charlie Kaier. Our interviews and reviews are produced and edited by Amy Salit, Phyllis Myers, Sam Briger, Lauren Krenzel, Heidi Saman, Therese Madden, Thea Chaloner, Seth Kelley and Joel Wolfram. Our associate producer of digital media is Molly Seavy-Nesper. Roberta Shorrock directs the show. I'm Terry Gross.

(SOUNDBITE OF ALLISON MILLER'S "VALLEY OF THE GIANTS") Transcript provided by NPR, Copyright NPR.