You are listening to a press conference from the Harvard T.H. Chan School of Public Health with Michael Mina, assistant professor of epidemiology. This call was recorded at 11 am Eastern Time on Monday, June 1.
Previous press conferences are linked at the bottom of this transcript.
Transcript
MODERATOR: Alright. Dr. Mina, do you have any opening remarks?
MICHAEL MINA: No, I will take any questions.
MODERATOR: Alright. First question.
Q: Hi, Dr. Mina. Universities are starting to gear up with testing or at least talking about plans for testing. One university here in Boston is planning on doing thousands of tests, RTPCR tests, per day in the early fall in time for the return of students if they are allowed to return. How realistic is is it to think of testing thousands of people per day? And is it a good idea?
MICHAEL MINA: So I think it’s getting it’s getting increasingly realistic, whether it’s the exact protocols we’re using now or some modifications of them or potentially entirely new technologies that are coming about, antigen detection tests that are point of care, essentially. So I think that there can be expectations that we’ll see a lot of testing for the virus in this case and in universities, as you’re saying. I think that if it’s going to be PCR testing performed in a central laboratory, it’s going to require new changes to how we do perform the swab.
So, for example, right now, to get a test, most people are still getting a nasopharyngeal swab that’s applied by a health care professional. But what we’re seeing increasingly is that these swabs, or the type of swab that can be used is moving more and more towards into anterior nare swabs. These are just swabs that you can self administer to essentially the front of your nose rather than all the way back into the nasopharynx. So that can provide an avenue any way, for example, students to be able to swab themselves each morning or every other morning and bring the swamp to someplace in a dry tube and drop it off in a bin where it would then get collected and processed later that day. So I can see an avenue where this would be occurring and I’m in some instances advising institutions to do just that, because I do think it can be useful. Whether every day is necessary, I don’t think every day would would really be necessary.
But what we do need to see is pretty frequent sampling at the very least when outbreaks are going on. And so I think what we can also envision is that we may see systems some institutions might put in place where sampling is dynamic. So you actually increase the frequency of sampling if you know that there’s active transmission ongoing within an institution or business, for example. And if you’ve gone a number of weeks without any new cases, maybe you can start relaxing the frequency with which testing is happening, with the expectation that if it starts again, you may miss the first few cases, but hopefully you can then quickly find them as long as your sort of weekly or biweekly testing is comprehensive. So I think that there’s lots of different ways that we’re going to see testing be used to get students back into universities and get businesses back to work.
Viral testing will be one part of it. Antibody testing will be another part of it, and mask wearing is going to be increasingly important. But even that, I think, will also have its difficulties on college campuses. And so we’ll have to think creatively about how to best incentivize wearing masks, when it’s the most appropriate time to wear them, recognizing that not every college student is going to be adhering to all of these policies all the time. So hopefully that answer the question.
Q: Yes. Thank you.
MICHAEL MINA: Sure.
MODERATOR: Next question.
Q: Morning. Thanks again for doing this. I was wondering what you think about the protests that have been going on and whether people have been making themselves vulnerable to infection. And what can or should be done about that?
MICHAEL MINA: Yes, I mean, certainly the protests are, without commenting at all on the protests themselves, I think there are certainly areas where we can anticipate seeing transmission occur or at least risk of transmission increase. It’s another one of these things that we have to balance as a society. We’re balancing economics against prevention of transmission and in this case, we’re balancing freedom of speech and freedom to protest against the epidemic parameters around the infectious disease.
And so I think that there’s no doubt in my mind that these can become breeding grounds for this virus. The one benefit is that they tend to be outside. And so hopefully on breezy days, it can distribute. If somebody is sick, then hopefully the viral particles that come out of somebody will get distributed in a way and diluted down so that they don’t actually infect anyone. But I would not be surprised to see that in the next couple of weeks, we see increases in transmission that may be linked to the protests.
It’s going to be hard to say because at the same time that these are happening, we’re also seeing businesses start to go back much more actively this week than in the past. And so disentangling what the sources of new outbreaks that we may see in the future will be important to do, so that we understand is this on these bursts of of protests or are we seeing increased cases as a result of those of businesses open back up. And we’ll have to kind of be very careful about how we evaluate that data if we see new cases come about.
Q: Do you think masks will be enough to protect protesters or if you were a protester, would you be wearing a mask as well?
MICHAEL MINA: I certainly would. I think that masks, will they be sufficient to stop any transmission? Probably not. If there is a floridly positive person who is coughing and spending a whole day around a lot of other people protesting, then I think we can anticipate that that person might very well get other people sick despite having a mask on. That said, I do believe that masks, they do block transmission to a certain extent, sometimes very well. And if both parties are wearing masks, as we’ve seen a lot more in the media and with people doing it, I think that there’s a good chance that even homemade masks will actually do quite a bit to help people not get infected and not transmit.
MODERATOR: Next question.
Q: Hi. Thanks for doing this. Just kind of branching off that question. Are you worried about kind of a lack of focus around the country? I mean, there’s other issues and there’s focus on them and rightfully so. But do you worry that people both with the summertime and all the other issues that are now dominating the news, that people will kind of not concentrate on what they had been in terms of social distancing, safe practices, that kind of thing?
MICHAEL MINA: Yeah, absolutely. And this is something I said. I remember saying it to a senator months ago when somebody called me up and asked, you know, what can we do, what message can we do or what can we do from our office? And my advice back then, and it would still be the same, is to prepare people to recognize that when things seem like they’ve died down and that the transmission has become under control, that that’s the time when people really need to continue being vigilant.
And we’re seeing the consequences of not getting that message out quite widely enough is that expectedly and not necessarily wrong. People are very, very antsy to get back out into the world and to their friends and to their normal existence. And whether that’s being catalyzed by protests or not, I think that it’s certainly worrisome from an infectious disease perspective. But again, it just needs to be balanced and I do worry that people are becoming much more relaxed about their precautions. Luckily, we have seen large reductions in the case counts, at least from peak. But we’re not anywhere near where I think we should be to really be able to safely go about our days. We know that there are still thousands and thousands of new cases occurring in this country every day so that each one of those, like I’ve said here before, each one of those can start their own new transmission chain in the same way that they could have two months ago. So certainly I hope that people remain pretty vigilant, in particular about wearing masks if they’re going to continue or start to sort of socialize again.
Q: Thank you.
MODERATOR: Next question.
Q: Hi. Thanks for doing this again. Going back to the protests, you mentioned the increased risk of transmission. Can you talk about where will you see us in terms of the infrastructure? Do we have enough testing and contact tracing capability to handle massive protests where you know you might see that kind of spread, especially in urban areas, you know, Atlanta and other major cities where people are more densely packed to begin with when they go home from a protest? What do you think of the infrastructure?
MICHAEL MINA: I think that we are getting – it’s getting there in a lot of in particular metropolitan areas. I think that we do have a much greater capacity than we did. Here in Boston, we have a lot of unused capacity, and that’s because a lot of capacity was built and was necessary during the surge and sort of the peak of this. It might be necessary, it likely will be necessary in the future. And so I think that even if there’s super spreading events, I think that relative to where we were, which was sort of the entire population prevalence has now come down, I think spread that occurs within within groups of protesters probably will not overwhelm the laboratory system at this point.
In some areas that may be more rural, where people are coming together but where the testing infrastructure wasn’t put in place, for example, but maybe protests are catalyzing areas that aren’t quite so densely populated to form more densely populated areas, you could see, I would expect, that if there were big outbreaks in those areas, you might end up seeing the local resources being overwhelmed.
But we have seen a lot of increase in capacity for testing and away from the big companies like Lab Corp and Quest that can ideally pick up a lot of that slack. The question will be, are one of the things that continues to plague is still the availability and ready access to getting swabs and just the testing material. It’s not impossible anymore. There’s not, you know, we’re not having to go through weird blackmarket seeming trade mechanisms to get them. They were legit, but they felt blackmarket-ish. But I think that we’re still seeing difficulty getting swabs and the materials needed. And so that might then might end up becoming more of an issue than the actual testing capacity.
Q: In terms of contact tracing, given the protests?
MICHAEL MINA: Yeah. Contact tracing would be extremely difficult, I think. It would end up just probably being ‘were you are at the protest’ is my guess. And it would prove very difficult overall.
Q: Thank you.
MODERATOR: Next question.
Q: Hi there. Thank you, Dr. Mina. Can you discuss some of the serological studies and the prevalence? We’re seeing lots of different numbers. Which studies are most important? And what is this telling you about the extent of the virus in the population?
MICHAEL MINA: Yeah, so serological studies are finally getting underway that are appearing to be more accurate. They’re not all just based on convenience samples. I actually want to use this moment to clarify something. I think it was last week CNN reported this terrible headline that half of all serological studies, serological tests are false or incorrect, which was fully inaccurate on their part. They said that the CDC guidance mentioned that. But there was a real misunderstanding of the CDC guidance where the CDC was just using a representative example to explain positive predictive value, not actually referring to a real test. And CBS and CNN apparently interpreted that as the metric that all of these tests are falling under, which was just wrong.
So, for example, the Roche and the Abbott assays are now over ninety nine percent specific. So I’ll just say that not all tests are 50 percent wrong or anywhere close to that. A lot of them are well above ninety nine point five percent specific and nearly 100 percent sensitive. So that said, now that we have good tests that are available, and these are generally tests that are are available in the laboratory and not so much these little plastic point of care tests, we’re seeing good serological prevalence studies coming about. And what we’re seeing is a lot of them are falling somewhere around five or six percent prevalence.
We’re still seeing, of course, pockets where prevalence is much higher or whole cities like New York where prevalence is much higher. 20, 30 and maybe 40 percent in some places of New York City. And so what that’s telling us is, a), that this is a very heterogeneous virus. It will transmit very quickly in very densely packed places. And it is unfortunately transmitting, not surprisingly, in lower socioeconomic housing facilities and things like that much more quickly, as well as nursing homes.
And so those are the places where we’re seeing clusters of much larger numbers of people in higher prevalence. But at that overall population level, I think what it’s telling us is what we sort of knew, which is a) there probably been around five percent of the American public, maybe maybe a little bit less has been infected, though to really extrapolate any ounce for the whole of the United States isn’t probably the right thing to do. But it means that we have a very, very, very long way to go before we actually have good population level immunity. And so we’re going to have to be very careful, in particular over the summer and then very careful in the fall when I think we’re very likely to see a big second wave of this occur if it doesn’t start in summer already.
And we’ll just have to see. But the serological prevalence studies fit what we thought, which is that still it’s not a huge number of people getting infected. It’s much larger than the number of people who have been confirmed with viral testing. But it’s still a small fraction of the whole population.
MODERATOR: Did you have a follow up question?
Q: Sure. Just a follow up is what do you think of reports that the virus may have been in the US, maybe the West Coast, in January and much earlier than would have been kind of stated earlier? Thank you.
MICHAEL MINA: Yeah. I mean, I certainly felt that way in January. The virus was transmitting throughout all of China in January and there were very many flights both coming straight from China or through Europe. And it doesn’t surprise me at all. Do I think that in January there was very widespread transmission? I don’t think so, but I wouldn’t be surprised if people infected with the virus did arrive in the US in quite large numbers in January, relatively speaking, large numbers. And then certainly in February, I wouldn’t be surprised.
Essentially the moment that we got testing up and running, we have to remember that we just didn’t test. We had less than a thousand tests, I think run all of February. And the very moment that we started testing, we saw cases. So that suggests to me that they were probably very many cases transmitting throughout February. And although they never made it onto the official reports, we can assume that they existed in the country.
MODERATOR: OK. Next question.
Q: Hi. Thank you so much for taking my question. As we’re starting to see reopening here, I’m assuming you still think that social dancing measures should still be in place. Do you have a kind of a general rule of thumb that you’d advise institutions in terms of how much distance needs to be maintained between people and maybe still, you know, steps that they can take to maintain that distance? I realize that’s a very difficult question, but I’m kind of looking for a brief answer to it.
MICHAEL MINA: Yeah, well, I think the – so, the whole six foot idea was really based around people not wearing masks. And that’s because that’s kind of how far you if you cough or breathe, that’s about how far droplets are theoretically expected to transmit. So wearing masks, you anticipate the larger droplets or just droplets in general really shouldn’t be getting out. It’s not that the virus can’t escape at all. But it will get out in very different, different sort of physical fashion than the than what was described when thinking about the six foot issue.
So I think that if people are very, very diligent about, if people are very diligent about wearing their masks, I think that we can actually consider scenarios where where we don’t need necessarily to have everyone six feet apart. If you have the space, great. But you know, one thing that I am very concerned about is by saying that or prioritizing businesses or institutions to open up first that can maintain the sort of distancing, for example, it might it might end up prioritizing certain institutions over others that might have the resources or the ability to create these sort of structural changes. And I think that one of the best things we can do is just be very diligent about wearing masks at work as people are going to go back into the workplace. And then I feel that there is a lot more room to navigate closer to each other. There will be risk for sure, but I don’t know that the six foot distance piece necessarily has to be set in stone if people are all wearing their masks.
Q: Thank you so much.
MODERATOR: Next question.
Q: Hi. Thanks for doing this. We saw some reports of Italian doctors saying that they’d seen a decreased viral load from this over the last few weeks and just wondered what your take on that is. Is there sort of any sense that the virus is changing in any way and just kind of what do you know one can say about that?
MICHAEL MINA: So do you mean the viral load that they’re measuring in the swabs? I mean, in the tests.
Q: Yeah. Yeah.
MICHAEL MINA: So that’s it’s a really interesting point, and it’s something we’re actually researching now. And I actually don’t think it has to do with the virus itself. It really has to do with who you’re testing. So if you’re testing the population at large and the virus and the epidemic is growing in cases, then what that means is that as the epidemic is growing, it’s usually growing exponentially. So every day, you’re getting more and more people infected. And the average, what we call age of infection and the duration of time that somebody has been infected is generally short. Maybe the majority of people who are infected today, if it’s growing at the beginning of an epidemic, have all gotten infected in the last four or five days, for example.
On the other side of the coin is the tail end of an epidemic when most people that are getting infected or most people that are testing positive have actually not just been infected in the last four days, but maybe were infected a week ago or two weeks ago. So we see this asymmetry. You see it like this compression at the beginning of an epidemic where most people who are testing positive have more recently been infected versus at the tail end, when you’re seeing sort of the stragglers remain and the positives are oftentimes caught when they’ve been infected for a longer period of time. So that changes the period.
Essentially, what it means is that on average, the time at which the average positive person is getting tested, if it’s through screening mechanisms, is going to be increased since the time that they were exposed. The time that they get tested is going to be longer when it’s at the tail of an epidemic. So that means that the average viral load that somebody is able to measure is going to be, on average, less at the tail end of an epidemic versus the beginning of an epidemic. So it’s a weird, it’s a very difficult concept to grasp because we’re usually thinking of testing and individual counts within somebody’s nasopharynx as specific to that individual. But there’s actually this epidemic population metric that can help define what that is that is not intuitive. So I don’t actually think that it’s a change in the virus itself. I think it’s a change in the population parameters, which most physicians wouldn’t necessarily be thinking about in general. I’m happy to answer more about that off-line because I know that that was very confusing.
MODERATOR: Next question.
Q: Hello. Thanks for taking questions. So I know that in some places, counties that have started reopening because they had controlled case numbers, once they did start reopening with restrictions, saw doubling of case numbers. And I wonder if you can just speak to the tension between protecting the public health and reopening the economy and just what the considerations should be there and what we should take away from those sort of those learning. Should these serve as case studies in what happens if you reopened too quickly or do you have any thoughts on that?
MICHAEL MINA: I think there’s a few pieces for. On the one hand, the longer we can wait to reopen, we’re hoping that when we do reopen, we can keep things sort of at equilibrium where we have a constant set of case, constant number of cases a day and maybe have some flexibility to see an increase to a small extent. So the longer we can wait to reopen, the better, because in general, what we’re seeing are declines.
And so if we get down to a lower level at baseline, then we can kind of hope to maintain that rather than a higher number. But I think we can learn from these. I personally think that we should be taking every opportunity we can to treat this as a natural scientific experiments where we’re watching different ecosystems open back up. And we we should be creating definitions around what one program versus another looks like so that we can have some way to measure them as they proceed into the future so that we can actually understand what is happening. And maybe what are the drivers of some programs failing versus some succeeding to maintain low numbers of cases.
I think the question about how to balance it is just – it’s the most crucial question I think our society has had to ask in, you know, certainly in decades, if not centuries. And that’s sort of how do we balance this potential catastrophic economic consequences with potential catastrophic infectious disease consequences? And so far, most of the approach to this epidemic has been through the eyes and through the lens of infectious disease epidemiologists like myself and others who have been suggesting certain policies surrounding containment of the virus and controlling this virus. But I think we’re at a point now where those policies now that, at least in settings where we have seen reductions in cases come down to not yet manageable, or not yet ideal, but certainly getting increasingly manageable case numbers in certain areas, I think the discussion really has to come together with economists and people who look through different lenses to ensure that we’re not potentially causing permanent destruction, for example, in our country as a result of containing the virus for right now.
And, you know, where the lines are and how that balances out, I think is a societal decision. It’s not any one researcher’s decision. There is no correct answer there. There will be different views. And all of this will come with with massive amounts of tradeoff. And so I think that we’re at a point, though, where the discussion is to really open up and to how to balance the infectious disease epidemiology with the economic epidemiology and the potential for poverty and homelessness and joblessness in the future.
MODERATOR: Next question.
Q: Hi. Thanks. I had a question about nursing home testing. I know the administration has been urging states to do widespread testing of nursing homes and residents and staff. And a lot of the homes say they don’t necessarily have that capacity. I mean, do you think that there’s a middle ground here, that there’s a way they can get the capacity to make sure that everyone has a test? Or is there a different way that they could go about making sure that everyone is safe?
MICHAEL MINA: Yeah, and this comes back to these issues of not having just the swab still aren’t completely, readily available to all the nursing homes, for example. And the ability to sort of do the nasopharyngeal swab still is not widespread within nursing homes. In much of Massachusetts, we had the National Guard and E.M.S. Services go in and test most of the nursing homes rather than sort of the nursing home staff doing it themselves.
So I think the only way to really make it sustainable is going to be to change the types of sampling technique that’s available. So probably to these more simple front nasal swabs rather than the nasopharyngeal swabs and ideally that the staff themselves will be trained to be testing the residents or, you know, one. approach is to really recognize that it’s not the residents who will be transmitting the virus back and forth, but it’s really the staff who might inadvertently bring the virus into a nursing home. And so I think that we can use that type of understanding to recognize new areas where we can potentially intervene better than others to prevent transmission by – maybe the programs can have very intensive, more frequent sampling of just the staff.
And then less frequent sampling of residents when there’s a staff member who’s recognized to be positive, for example. But I think that what you bring up is a is an extraordinarily important piece, which is that in general. The the resources just haven’t been there. It was an extraordinary effort to get Massachusetts nursing homes tested just once and they had about five weeks to do that and they succeeded. But it was a massive, massive effort with a tremendous number of people involved to make it happen. And so the thought of doing that every week is it just wouldn’t be feasible. So something needs to give. And I think using more sophisticated sampling strategies and public health strategy to figure out who’s best to sample and when is probably a good way to improve efficiencies.
Q: Is there a way to to bring down the cost or do you think eventually that the tests might become cheaper to run? I know a lot of the industry have said that, you know, aside from not even being able to access the materials, it’s just the cost of doing the tests themselves is a barrier.
MICHAEL MINA: Yeah. So the cost is certainly a barrier. PCR is generally somewhat expensive. But what I think will happen is we’ll see viral tests that get onto the market that are much cheaper. And some of these might be – one of the things that I think will change, and this will be for nursing homes and for economies around and other businesses, there will be a more rapid sort of test that come about where people can self-administer it and have a viral result in minutes rather than having to do this whole PCR test.
I don’t know that everything will move away from PCR, but I do think that these antigen detection tests – they’ll be akin to pregnancy tests or even more simple, like little paper strips – I think that we should expect to see them in the semi-near future, in the next couple of months or maybe a little bit longer, maybe shorter. And that will really be a game changer. They can be made cheaply, they can be made in the millions and they can provide very accurate results. They are sometimes not quite as sensitive as the PCR test with the nasopharyngeal swab.
However, I would say that you can, but the tradeoff is well worth it if you can have more frequent testing of more people at the expense of sudden loss and sensitivity. That would be fine because they’re all going to be more than sufficient to find a positive anytime during the period of time when that person might be transmitting, for example. So a lot of the sensitivity loss in some of these assays is really recognized when people are at very low positive values with their viral loads and they’re probably not transmitting by that point anyway. So it’s sort of not clinically meaningful to catch those people anyway. So I think we’ll see a change in testing practice that will make it more feasible.
MICHAEL MINA: One more question. Sorry about that.
MODERATOR: Alright. Thank you. Next question.
Q: Hi. Thank you. Just very quickly, your audio cut out very early on in the call, just briefly. It was right when you were talking about, I think you were saying that because protests are largely outside that there might be the potential for some dilution. Do I understand that correctly? And would potentially either temperature or humidity help?
MICHAEL MINA: Yeah, I mean, the temperature issue has come up again and again, again, and I think we still don’t fully understand that part of the biology very well. But we know that there is clear seasonal attributes to corona viruses as many respiratory viruses. And so we are, I would say that we’re hoping that that seasonality will remain strong this summer and we’ll see less and less transmission as we move into the summer, all other things held still. We hope that that will play a role. There is a potential way that that can backfire, which is, well, I mean, for the short term if we’re talking about the protests, then that would be a very good outcome is if the weather is actually going to help prevent some of this transmission that would otherwise occur.
The backfire that I was going to mention is more long term, which is if people get very used to having very low numbers of cases throughout the summer, then we might see society get caught a little off guard as the fall comes in and cases really start to sort of rear their head again as a result of changing climate or changing temperatures. And so I think that we we just have to be cognizant. If we do see the benefit of summer to really reduce transmission, for example, we will have to all be really watching as we move into the fall to make sure that we are not inadvertently sort of starting massive outbreaks again once that sort of grace period ends from the summer.
This concludes the June 1 press conference.
Bill Hanage, associate professor of epidemiology (May 29, 2020)
Leonard Marcus, founding co-director of the National Preparedness Leadership Initiative (May 27, 2020)