You’re 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 11:30 AM Eastern Time on Monday, May 4.
Previous press conferences are linked at the bottom of this transcript.
Transcript
MICHAEL MINA: I don’t have any particular opening remarks, I’m an assistant professor of epidemiology and of immunology at the school of public health. I’m also molecular virology laboratory director at Brigham and Women’s Hospital and have been very active in developing and leading some efforts for high throughput virological testing and more recently, trying to work on serological tests and can speak to any number of these various items. So happy to take questions.
MODERATOR: Great, thank you Dr. Mina. First question.
Q: Good morning, has a level of antibodies been established yet that would confer immunity?
MICHAEL MINA: No. Those studies are beginning now, but they’re going to take some time, in particular because we have to wait to see people who get re-exposed and then be able to measure a sufficient number of people, both at baseline and then as they become re-exposed to the virus the second time or third time, for example, we will have to be monitoring them so, we’re setting up, and we being a collective we, researchers throughout the country and throughout the world, are setting up various studies to be able to follow and monitor people who have already been infected and be able to measure antibody levels before and after they get exposed to see which ones actually become re-exposed a second time, but they’re exceedingly difficult studies to do quickly because we have to wait until natural exposures happen following a primary exposure. Is there any follow up with that?
Q: Well, if I am allowed to follow up. Sure. Yeah. Thank you. You know, we’re seeing some articles talking about various European countries being at an R0 factor of 0.6, some 0.8, What does that tell us and you know, can this be accurately measured, and if so, what is it for the United States? I know in the past, you’ve talked about how it would vary according to population density.
MICHAEL MINA: Yeah. So essentially, if we’re seeing R0 fall below one that’s oftentimes, in this epidemic anyway, as a result of social distancing and not so much a result of herd immunity. I’m trying to understand is the question centered around antibodies or is this a whole separate question?
Q: No, I mean, this is not a question about antibodies right, this is more a question about the R0 factors and what they mean and whether we can determine whether there is one for the United States and how we can compare to European countries, which seemed to have one below one at this point.
MICHAEL MINA: Sure. And certainly, if you look at various cities. I mean, we’re going to start seeing, if we start to see, cases dropping for long durations of time when we start calculating the effective R0, so it’s really the effective R, and not so much the R0 anymore. That will help us determine sort of where we’re at in terms of the epidemic, and I think we will continue to see many countries throughout the world drop their effective R values, hopefully below one which will mean that the epidemic is sort of dying out. But I think it’s very, very important to realize that this is somewhat of an unprecedented issue, because normally we would assume that if the epidemic is dying out and the and the effective R is below one, that usually assumes that either we’ve hit herd immunity and or getting or nearing herd immunity threshold.
So anyways, so we’re actually starting to push the number, the average number of people that each person infects down to below one. However, this is a very different situation because although we’re seeing effective R’s drop below one, it’s in a way, you could think of it as artificial, because we are social distancing in order to drop those values considerably. If everyone goes back to normal in those European countries in terms of their normal routines, their behavior is going back to work and R continues to be below one, well, that would be surprising and very encouraging, but we don’t really anticipate that will happen.
We assume that much of the drops in values have been a result of our actions, our collective actions as a society, to really drive our below one. And as we begin to open up, we are assuming that things will start to increase again. And we’ll have can monitor, but that’s the real concerned about opening up the sort of too quickly, is that that R might jump right back up to three or five or whatever it is in the various locations. So I would say that it’s it we have to interpret it a little bit differently than we’re used to, because we’re not used to interpreting R in the context of extreme social distancing like we’ve seen across the globe.
Q: Thank you.
MODERATOR: Next question.
Q: Hi guys, thanks for taking questions. You may have seen today, many of us are reporting the, the FDA is out with a new policy on regulating antibody test. Basically, it kind of sunsets the notification policy where companies could launch by just notifying the FDA their plans. They’re now going to have to submit UA’s within 10 days. Can you just talk a little bit about what’s been the effect of having so many of these tests in the market till now, and whether that was a helpful policy or just you know what your impression as a researcher and public health expert has been of how this has gone so far?
MICHAEL MINA: Yeah, I think I’m, it’s been a little bit unfortunate to see market get flooded with poorly optimized serological tests. And this is, I think, what it’s done. It has sort of led to a lack of a lack of understanding of how serology can be used. In general, I would say that the conversation has been really driven by concerns over inaccuracy is of the test, which are very valid. A lot of the early tests that have been performed, especially in some of the serological studies that have been performed, have been less than ideal in terms of their accuracy. But so, in some ways, as in particular I’m somebody who, in my normal life outside of COVID, is focused on the development of very high throughput, high complexity serological tests. And so, I see the value and power in them when used appropriately. But I’m concerned that the public and policymakers have sort of lost faith or lost trust in the power of looking at somebody’s antibodies when in reality, I think that the serological evaluation of blood is, in many ways for surveillance moving forward, as or more important than surveillance via viral testing.
And so I’m hoping that we can move beyond some of these initial point-of-care instruments that came out very early, and were readily available and we can start really focusing on real serology, or I should say, just serology based on more accurate assays that are done in in high complexity [inaudible] laboratories, for example, and that work well and give quantitative values and that we can trust clinically. So I do think, though, that the initial rollout beyond just the biology, I think it’s confused a lot of people as to the utility and potential benefit of making serology a mainstay of surveillance, when in reality, under normal circumstances serological surveillance is a much more common and much more robust way to monitor for epidemics and infectious diseases versus testing the population for the pathogen itself, especially for a transient pathogen, such as this coronavirus.
So I hope that we can recover from this and as government agencies and policymakers continue to put in place, pathways for surveillance into the future as we open up society again, I hope that we kind of come back and recognize that some serology tests are really very accurate and can be very powerful to monitor a virus such as this. But I, I worry that there was some damage in terms of the messaging surrounding serological tests ,that now the average person might who doesn’t know about these tests in depth, might have gotten the wrong idea that that antibodies just are totally unreliable.
Q: Great. And if I could follow up. So it sounds like you still have hopes that these tests will be useful in helping determine immunity and having a role in in using social distancing. If so what still has to happen? What are sort of the research hurdles we need to get over to be able to use them in a practical manner like that?
MICHAEL MINA: Sure. So there’s been a lot of discussion, for example, suggesting that we don’t know what the immunity will look like from this virus. And that’s absolutely true. But we do know that the body handles this virus in a way that seems to be consistent with how the body handles other viruses. And we know that there will be some immune response. We’ve already measured the antibodies in many people so we know that an immune response is there. We just have to better, get more nuanced information about what those responses mean and how to interpret them.
We need to set up these studies, like I mentioned a few moments ago to follow people to see are there thresholds of protection? That if somebody gets infected once will they get infected a second time? Or if, you know, and whether that’s with symptoms or without symptoms, can they still serve to shed the virus if they get re-exposed a second time, potentially months after their first infection. And then we need to really be in this for the long haul to test, to continue to follow people for months to years to really understand what will be the durability or the duration of immunity following infection. For in large part, from following an acute respiratory virus like this we can usually assume that there’s going to be a period, some window of protection. That might be three months. It might be six months. And it might wane after a year or two, and that might differ based on age as well so it could be that somebody who gets infected in their 60s, their immunological response might wane more rapidly over the next year than, for example, somebody in their twenties or a child.
So those are the studies we are going to have to be doing moving forward. And these are similar studies that we still do all the time for viruses that normally infect us before this coronavirus came about. Measles, for example, it’s still an open question about what the waning rates of immunity for things like measles and rubella and mumps look like. So this is going to just become another area where we have to keep being diligent about studying these immunological responses.
MODERATOR: Great. Thank you. Next question.
Q: Thanks to call and thanks for doing this., Doctor. Appreciate it.
MICHAEL MINA: Absolutely.
Q: I’m curious to know, you tweeted the other day about reopening too soon, and the dangers of that. Could you go into some detail on that for us?
MICHAEL MINA: Sure. So one of the concerns that I personally have and I think a lot of epidemiologists have is, so we’ve seen this whole epidemic essentially get ignited by potentially a very small number of initial transmission events, for example in Wuhan, in the market, zoonotic events into humans. And then in the States it was probably you know maybe tens, maybe, maybe more than tens. It’s unclear how many individual imports, there were, but suffice it to say, there was a smaller number of actual imports of the virus that came into the country and ignited the national epidemic that we see across the United States. And this was anticipated, so it doesn’t require very many transmission chains to start a large epidemic that then spreads.
What the concern is now is if all that we’ve seen was able to be started by handfuls, or maybe tens or more, of individual events, of individual imports of the virus into our communities through international travel, we are now in a very different spot. So we, as long as we keep social distancing we’re going to see the infections diminish further and further. But we now have tens of thousands of infections that continue on a daily basis throughout the United States. Each one of those is able to act in, in many ways, like an import from an international site did back in January, for example.
And so what we’re particularly concerned about is if we open things up too quickly today or in the coming months and we still continue to have thousands or tens of thousands of small transmission chains of this infection ongoing sort of throughout the communities of the United States. Then, as each of those communities begin to open up we still don’t have sufficient herd immunity to, for anything different to happen than what we saw in January and February. Maybe the weather will help, we’re not sure, but what that means is that, as things open up on any one of those transmission chains or thousands of them could potentially ignite new outbreaks and and then you know so so that’s that’s how these things, that’s how what we call a second wave of this epidemic can potentially be more destructive and more damaging and larger than the than the initial phase of the epidemic, which was sort of, it started and it happened in kind of a single or a couple of major waves that kind of started from the coasts and went inward, if you will, from these international flights. Now we just have the equivalent of imports sitting amongst us throughout our communities and it really does have a danger there.
And the way that I think of it, if I were to try to explain to somebody who doesn’t understand epidemiology at all, I would say if you have a big forest and you start a spark on one edge of that forest. It has the potential to to burn through the forest. But you can kind of monitor it and watch it happen, it might jump around. And that’s kind of what we’ve seen in the phase. The first phase of this epidemic. But now, essentially, we still have a tremendous number of hot embers sitting throughout the whole forest as a response. And we still have most of the trees and brush did not get burned down and if we stopped sort of pouring water on the whole forest, if you will, any one of those numbers are many of them can ignite very rapidly. And that’s a big, that’s a big concern for what might happen.
Q: Is there any way that it seems like governors and other public officials even health officials are focused on flattening the curve. It doesn’t sound like, is there a way that you can look at it as an expert and say, okay, now is the time to start reopening or is it a crapshoot no matter when we do it?
MICHAEL MINA: Well that’s good question. I think I wouldn’t call it a crapshoot no matter when we do it. I think that once again we have sort of squandered this time that we had through social distancing. There’s been a lot of conversations, but relatively little concerted or sort of central action to create the, the types of systems and early warning and monitoring systems that I think are really necessary. I don’t see that we’ve used the last couple of months and the public health sphere across the country, in a way that has readied the US today to be in a much better spot than it was two months ago to be open. So without surveillance systems very sort of engaged surveillance systems that have the potential to identify these small outbreaks when they start to occur and sort of tamping down before they get out of control without a lot of surveillance ongoing or at least the system set up to allow it, I think that we are going to be running a risk either way.
And I think that to really open up, we should have some of these surveillance efforts in place. And they might be everything from actual testing of antibodies of for virus, to really developing a good infrastructure to make use of mobile applications and iPhone type of apps, for example, to look for epidemics and outbreaks throughout the communities in the US. But I haven’t seen any real central action, particularly from the federal government to really push this. Different states have been working hard to get their own constituents, some some different levels of preparedness, but I don’t see any. I can’t point to any place in the US that I that I would feel good about saying, I think that now is the time for that place to open up.
Q: Thank you.
MODERATOR: Next question.
Q: Yes, hi. I hope you can hear okay my connection is not great. There’s a lot of discussion at the moment about vaccines as well as antibodies and I just wanted to get you said that it’s can take a long time to get to, you know, effective antibodies, you know, relative to what you would expect with the vaccine, you know, do you expect it to happen a lot before that, you know, there’s obviously a lot of discussion about how long it takes? 12-18 months or much longer, but in terms of antibodies would you expect for, you know, good tests to come, long before a vaccine or not necessarily?
MICHAEL MINA: Oh, absolutely. I think we already have the tests that will be that will be useful for measuring antibodies. And now what we have to do is figure out how to implement them appropriately and how to be able to interpret them appropriately. So I think that the the antibody tests exist or even, we are even producing neutralizing antibody tests which are a little bit more directly able to look at whether somebody’s blood is able to neutralize the virus, rather than just measuring the bulk antibodies against a specific viral protein. So those do exist already. And I think that we can anticipate even the studies to understand how better to interpret those results. I think that we’ll start to get the information from a lot of the studies that are being set up now within the coming months. And so my anticipation is that we will better understand how to interpret the antibody tests probably many months before we have wide availability of a vaccine.
MODERATOR: Next question.
Q: Thank you. So can you go back to the discussion we just had about states because many are just ramping up testing, the virus testing and they’re also doing what’s called contact tracing and then in an effort to isolate people. Can you comment on the effectiveness of that?
MICHAEL MINA: Sure. So contact tracing can be an integral part of of control measures and it’s famous for its ability to monitor and track and help control outbreaks, but contact tracing certainly has its limitations in particular when wides when the the infection that is being monitored becomes widespread. And so, for example, and I think that I’ve given this example before, but if there is, let’s say, a nursing home with 60 % positivity rate for virus, then contact tracing everyone who’s positive in that nursing home might be, might have, severely diminished returns. It’s hard to know exactly what would be the purpose of contact tracing each of those individuals, especially what we were seeing as a lot of times the contact tracing it is happening across United States is delayed. And if this was something like HIV, which sticks with people for life, then contact tracing somebody who becomes infected and is found to be positive, contact tracing and going and finding them weeks later would be an acceptable timeframe. Not ideal, but it would still be useful. However, with an acute respiratory virus that tends to be cleared within a week or two of infection, going back, and all of the transmission tends to happen probably largely within the first week, going to that individual and trying to track down their contacts from 20 days back, for example, really doesn’t have a ton of utility to try to stop the virus.
To really make contact tracing useful you have to be ahead of the virus, you have to identify people when they’re sick, you have to identify all of their contacts who might not yet be showing symptoms and get them to isolate, but if you’re if you’re running two weeks behind the virus, like we’ve seen a lot of the in a lot of the places in this country where contact tracing has been employed, it has only a limited capacity to help and, on the other hand is extraordinarily resource intensive as a way to monitor and track an epidemic. So I think that there can be, if done appropriately, it can be absolutely crucial and I anticipate that if we continue to see the effective are be below one and we get cases to a more manageable level than they are today, then contact tracing could become very useful.
If you have a system in place to detect an outbreak as it’s beginning to play contact tracers there, find all the contacts and isolate individuals. That would be a useful approach to preventing those outbreaks from becoming larger. At the moment, though a lot of these outbreaks, and we still have wide-scale transmission, and so how useful this contact tracing events, these contract tracing programs, have been is unclear and I haven’t seen a lot of evidence that they’re being deployed in a way that’s efficient relative to the resources required.
Q: Right, if I can ask one follow up because the White House reopening plan talks about the criteria of seeing a 14 day decline in positive cases or the percentage of positive tasks. So when you have, and if their approach is to do all this testing out the contact race and that’s as you know when you, when increase testing you increase the number of positive cases. So it seems a bit counterintuitive to me and I just wanted to get your perspective on that.
MICHAEL MINA: That’s, that’s correct. As you increase testing you will increase the absolute numbers, hopefully you would decrease the fraction positive, ideally, but it depends on how you’re deploying your enhanced surveillance. And I do think that,, I think that it’s important to see a reduction for two weeks. But having a reduction for two weeks doesn’t mean again that this outbreak is necessarily is different than it than it has been. It just means that we’ve done a good job at social distancing and stopping spread and that’s where this really becomes a tricky balancing act. We do need to open up. Absolutely. We need to figure out how to open up, but we need to do it in a way where we have real surveillance and actually useful surveillance in place and it’s not yet clear what exactly that would look like, given the resources that different programs would require, but certainly, just saying we need to see a two-week drop in cases doesn’t really imply much to me.
I would like to see a two week period of time when there are no cases before opening up or very, very few, not just a drop in cases day on day because, again, we may have become accustomed to seeing when, once cases start to go down in most other epidemics it usually means that the virus is naturally dying out from that population, either because herd immunity thresholds are being approached or serious weather or restrictions are in place. And this just can’t be viewed in the same way, even if the epidemic curves look like how we like to normally see epidemics sort of falling, and usually once we see two weeks of reduction, it usually means that that reduction will continue on. In this case, the reduction has been artificially enforced through social distancing, which was the goal, but it doesn’t mean we can open up and assume that it won’t just bounce back, so it’s unclear what the, you know I don’t know that I agree with that as a marker of went open back up.
Q: Thank you.
MODERATOR: Next question.
Q: Hi. Thanks so much for doing this. Um, let me just pick up right there actually. Does that imply that you are not, you’re uncomfortable with the White House’s gating criteria, and, if so, can you help me square the circle, because you said we absolutely need to open up, but also that you’re not sure that any state is ready yet. So if it’s not the White House has criteria, what criteria are we supposed to look at?
MICHAEL MINA: Well, again, I think that it’s not so much the criteria, per se, in terms of the infections it’s the, I think that it should be based on what sort of surveillance and what sort of programs we have in place to detect outbreaks as they begin. Unfortunately, I don’t see a lot of useful programs that have been in place to do so. We’ve had a lot of effort focused on viral testing, I think, for example, one place to start is to look for the gaps in immunity. Find communities where infections have not been widespread and also places where they have been widespread, and that can help inform whether to be concerned or not in terms of different communities or locations.
I think that we really need some sort of surveillance, either we need to have some serious surveillance efforts that in programs where we can actually test potentially for antibodies, rather than virus, because they might be more impactful in the long run in terms of the knowledge that we gain from it. Testing individuals on a regular basis for example, maybe businesses should have some programs set up to be able to test for virus or antibodies in their employees on a regular basis. These are the questions we’re talking about in various areas in Boston about you know, with local companies and businesses about how to open up. Do we need programs that would allow employees to be tested weekly or daily? Do we need to start using at least some information on whether or not outbreaks have occurred in a business, just to help inform how, what kind of surveillance that business requires, of course, that’s all sort of centered on, you know, again, how much immunity really helps. So I, there’s just so many unknown questions, but I’d be looking less at the number of cases and more at the programs we have set up in order to determine when a community is sufficiently at low risk of major outbreaks happening again because of surveillance efforts.
So short of that I think we, if we don’t have a good way to view when outbreak is starting, we run the risk of everything happening all over again. And it’s not clear, though, what exactly those programs will look like. I think there’s room to experiment with different programs because there is no gold standard here, but at the very least, there should be some organized effort to have programs that could be evaluated, if we if we set up different types of surveillance programs from high resource requirements to low resource requirements. Maybe we find that that we can actually do things efficiently with fewer resources through some sort of testing regime that’s as efficient as these very, very high resource requirements surveillance programs, but until we have those setup sort of nationally or at a state level, I think we’re really playing with fire.
Q: Can I just follow up one with one quick question? You mentioned the metaphor of the forest. How do you respond to the governors, whether it’s coming from the White House or whomever, that says there’s another forest burning and that’s the economy and and we’ve got at least open small things retail shops at 10% or, you know, the ones that are tiptoeing in in a in a more gingerly pace. How do you think about that, or balance that or what would you say to that, I guess?
MICHAEL MINA: I completely agree. Throughout this epidemic, I’ve been vocal proponent of social distancing and shutting things down, but very, very cognizant of, and concerned that there is the potential, the last thing we want to do is ultimately create poverty and have more people in the long term, you know, die of poverty and starvation in this country than would have succumb to the virus and, you know, that would be a worst case scenario. And we do not want that , we have to be, that has to be front and center of our of all of our decision making processes. I think of it as sort of, so far, the epidemic has been viewed through the lens of public health through an infectious disease lens and we really have to be balancing it in terms of public health and economic lens and where those two balance out is difficult to say. But what we know is society cannot really run particularly well if hospitals are inundated and do not, and the healthcare system doesn’t run properly.
So, for example, what I would say is, and I haven’t seen happen so much yet, is we should be using this time while we are social distancing maybe not to completely prevent all transmission, but maybe to maybe, one way to deal with this, is to put an enormous amount of resources into ensuring, in some way, the protection of the most vulnerable individuals in our, in our community. So far I’ve seen very little structural change that’s going to actually protect vulnerable individuals in nursing homes. You know, we’ve seen a lot of testing programs get started up, but I don’t see how those are necessarily protecting those individuals. They’re allowing us to observe when a nursing home becomes infected with this virus.
So I would suggest, you know, that’s one way to balance these is to, leverage the demographic uniqueness of this virus, which seems to be sparing the youngest and not sparing the oldest and most vulnerable, and build walls, you know, do whatever we need to do to truly protect the vulnerable and maybe then we can actually consider what are the risk versus benefits to opening up in particular because we don’t see a tremendous number of young individuals who are not vulnerable for other reasons, ending up in the hospital. So that would be one approach that would help balance it, but the problem is I just haven’t seen any structural change that’s protecting those individuals or that is really allowing heightened surveillance in any in any good organized fashion. So that’s kind of why I say I feel like we’ve just squandered the that we squandered February with testing and now we’ve squandered March and April in terms of preparing for opening. I don’t feel great about it.
Q: Thank you.
MODERATOR: Next question.
Q: Hey, Dr. Mina, thank you so much for taking the time to chat with us. Um, I wanted to revisit the subject of contact tracing if that would be okay? The state of Florida only has 500 contact tracers, we’re not getting any more, as per the Secretary of the Department of Health, they don’t plan on hiring any more. So we’re looking here at steps that citizens can take to make sure that if they test positive, they can tell, as many people that they’ve come into contact with as possible. And I wanted to sort of ask your opinion about the possibilities of social contact tracing, if that makes sense or community contact tracing and if you’ve seen any models in your experience that might work like that businesses, taking a list of customers or just packs between friends, things like that?
MICHAEL MINA: Yeah, well that was actually. It’s interesting the way you phrase it because I think, that as this epidemic was getting rolled out, South Korea, or was getting started, South Korea, for example, had very high levels of testing and. And one of the things that I was saying at the time is that one of the benefits of knowing your status, it’s sort of, again, there’s, there’s, I keep making these analogies of HIV. But one of the, one of the things that comes with knowing somebody status if you’re HIV positive, then you act accordingly because you try not to infect others. And if you if you recognize that there’s a chance you might have infected somebody else you ideally would let them know. And that’s something very similar. That’s one of the powers of knowing your infection status in this epidemic as well. It’s very similar. It’s different because the respiratory virus, but it would, it empowers people to be able to take extra precautions if they know that they’re positive and to let people know that they have potentially been exposed if they know that they’ve interacted with individuals.
So I think it can be a very powerful tool, absolutely, and I certainly encourage and I think it is one of the reasons why knowing, why testing can go very can go a long way to mitigating transmission because people tend to, I think, behave appropriately when they find out that they’re infected, they probably will not go and you know have dinner with grandma and grandpa if their child is infected, for example. And so that, in a way, is sort of an implicit type of contact tracing, or at least contact sort of response and isolation at the community level and I think that that’s very powerful. It’s one of the problems with not having sufficient testing is that people are not empowered to be able to take those sorts of personal actions. So I think it’s very important.
I also think it’s where mobile devices and these big players like Google and Apple could potentially assist in this program if they’re, you know, I don’t know if there’s, there would be a lot of privacy issues and I’m not sure if our country would really be, if our society would be okay with these types of programs, but if you wanted to participate in a social contact tracing sort of program that’s run through Google or something, I could envision, where if you’re infected you anonymously type, you know, tap that on your phone and Google can use, can monitor sort of where you’ve been and who you’ve interacted with even if unintentionally interacting with them stay at a grocery store to let other people know hey, you might have been exposed, somebody in your geographic network was just found positive. So I could see that there would be a lot of new ways to be able to do contact tracing and smart isolation without real boots on the ground to contact racers.
Q: Appreciate it.
MODERATOR: Next question.
Q: Hi, good afternoon. This is a natural extension of the previous question, it’s about the strategic use of serological tests. Do, even though we know there’s some caveats around whether you’re immune or not. If you’re zero positive, wouldn’t it be beneficial, say, for a family unit to know if one of their members had been previously exposed so that person could go to the grocery store and that would, I would think, protect both the people who work in the grocery stores and also the family members back home. Is that the sort of thing that epidemiologists recommend as strategies?
MICHAEL MINA: Yeah, absolutely. I think it has to all be couched within this sort of being maybe a little overly conservative at the moment about how to interpret these antibody results, but I do anticipate that people who are antibody positive will at least have a lower risk of infection than somebody who’s fully susceptible. So that would be absolutely one way to mitigate transmission, and I would probably, if somebody has to go to the grocery store, then it might as well be somebody who has already been infected and has recovered. I think it just makes sense from an immunological perspective so I would back an idea like that. And there’s also, there’s other reasons to do serology as well. For example, if, if you were to go to an apartment building or nursing home or wherever and test everyone in the community, just with virus, which is sort of how a lot of the programs are being performed right now for public health efforts.
You go in and you might find that 5% of that apartment building is positive at that moment in time for virus without serological evaluation of those individuals simultaneously you don’t know for instance, iff 60% of that apartment building was actually positive, a month ago and today, and that they’ve actually come down and now are only at 5% or if they’re about to become an epicenter for a new outbreak. And so that’s where I think serological evaluation has a huge benefit and probably a more powerful benefit than viral testing. If I had to choose one or the other would for surveillance efforts. So it almost always go with antibody testing because it gives you a snapshot it doesn’t just give you a snapshot of the now, it gives you a snapshot of what’s happened, up to now, so you know how to interpret that 5% positivity rate which side of the epidemic outbreak sort of swing, you’re in, in that, in that small sort of localized environment so there are a lot of really good uses for serology.
Q: One last question. I saw that Roche has a test that was announced in the Wall Street Journal this morning. Does it, when companies like that that can produce many millions of tests is that when we’re getting close to being able to test large swath of the population?
MICHAEL MINA: Yeah, it’s very hard and you know this is, it’s like deja vu or Groundhog Day or something. This is exactly what we saw with the viral testing and unfortunately, Roche can make all the samples, all the tests it wants, but the instruments that Roche, that these Roche assays run on, which are Roche instruments, are not generally set up in a way to a lab community based surveillance. These instruments tend to be in hospitals or commercial clinical labs and essentially the whole US healthcare infrastructure has been centered around testing for clinical purposes. Which makes a lot of sense. So but, what that means is there’s no good way to get samples from the community, from people who are not already enrolled in healthcare systems for example, there’s no, there’s no good way to get these samples into a hospital laboratory and tested and you know hospitals can maybe step in a little bit and maybe test an extra thousand people from the community a day.
But what really needs to be put in place are whole new, whole new laboratories that don’t exist in the United States that aren’t linked to clinical care and by that, I think it requires, we need a whole new laboratory system that’s centered around surveillance and where people can submit tests without a physician’s note, for example. And can be tested outside of the health care system because the Roche instruments and the Avid instruments and all of these other instruments, they are housed within hospitals that can’t just take in tens of thousands of extra samples a day just because Roche has extra test capacity in their reagent volumes. These, these. So a lot of we always say in Laboratory Medicine. It’s never the analytic process itself. It’s never the test. It’s the pre-analytics and the post-analytics. It’s all the logistics around and getting these samples in and tested and the results back out. And hospitals just aren’t the right place to do massive community surveillance, so I feel, on the one hand, I think it will be great for our hospitalized patients to get these nice Roche assays, being able to be performed on them, but I don’t know that those are going to bring us too far towards real wide scale surveillance.
MODERATOR: Next question.
Q:. Thank you, Dr. Mina, to you and your colleagues for all you’re doing. My question is about testing with nasal pharyngeal swabs on asymptomatic elders, especially in the nursing homes, and I do appreciate the importance of robust statistics. This question is predicated on the fact that our bodies have natural defense barriers such as the mucus ciliary tract and even something as innocuous and silly sounding as nasal hair, it is protective. Could it be that by sticking a nasal pharyngeal swab into the lower internal aspect of the hair, that would possibly introducing the pathogen further into the nasal cavity where elders have a more fragile um you COSA in that environment and that we could be introducing pathogenic virility and an area where we don’t want it to be? And I hope I’m wrong, and my theory. But I was curious as to what you thought.
MICHAEL MINA: So I agree that if you were to find an individual who just became exposed to the virus, and the virus was sitting throughout the anterior hair and hadn’t yet migrated back or grown are attached to any of the cells then I do think that what you’re saying could theoretically be the case, but in general the viruses are very, very small, much smaller than our hairs and so they tend to be able to move back as somebody breathes in a droplet from somebody else, for example. They can move back and replicate in the nasopharynx quite readily. So I think that in general, people are either going to have the virus sort of that’s already replicating. I don’t think that just if somebody has like 10 viral particles sitting at the anterior that you’re likely to do too much to really increase infection, but it is, it’s an interesting point and I think a theoretical possibility.
Q: Thank you.
MODERATOR: Next question.
Q: Oh yeah, thanks for doing the call. Um, how should we evaluate the month plus of social distancing and its results? It seems like hospitals are having an easier time of catching up, but also there’s a consistent caseload. I think 30,000 per day, 2,000 deaths per day in the US. Has it produced the kind of results that you might have expected or we still have a longer haul here?
MICHAEL MINA: Well that’s become a, I don’t know if it’s become a mystery, but it’s certainly I think on the one hand, yes, it has provided the results we anticipated we as social distancing came into effect we anticipated plateaus of cases, instead of continued exponential growth and that’s what we saw. And in many places in the country we are seeing reductions in cases per day. Still, many cases are occurring. But the US is extremely large and not centralized. And so what that means is that each program, each state, and each community has kind of been left to its own devices to do its own level of social distancing and that kind of spreads out everything, including the sharpness of the peak that we would have hoped to see. And so I think that what we’re seeing now is sort of this long very very slow, gradual reduction in cases that’s really now looking like a big plateau, is somewhat anticipated because we’re essentially spreading out all of these individual peaks over much larger, over geographically and then aggregating it across the country.
But we’re also seeing certain areas that just don’t seem to be able to get their cases down and these tend to be more metropolitan areas, for example, or other places that aren’t social distancing as much. And in that sense, I think what that’s exposing is just how transmissible the virus is. If this virus is more transmissible than sort of an R0 of two or three, but maybe an R0 of five or six in some locations ,which it very well might be. Then it really it is a very, very transmissible virus and it’s going to be extraordinarily difficult to really get it to stop. In particular, in places like New York City where there is just so much human contact. You can’t move around the city without contacting other people, whether it’s in your apartment building or elevator, the subway. So that’s going to pose a real challenge and I think that those are some of the issues, leading to why we’re not seeing sharp declines.
MODERATOR: Okay, great. Next question.
Q: Hi. Yeah. So is it possible to determine a national R0, or is it even worthwhile?
MICHAEL MINA: Well, I would say that, in general, that’s largely what’s been happening. You’ve seen people trying to determine global R0. And these are kind of like meta analyses of the R0, if you will, and that’s probably so it’s it’s hard to say. I think that R0 is probably likely quite a bit higher than two or three if we look at the doubling. So the R0 of two or three was really based on a lot of reports really on that doubling times of the epidemic were five to six days. My feeling on that was that that was driven primarily from a complicated relationship between the growth of the epidemic and the growth of testing facilities in different countries.
If we look at the actual doubling rates in many places, including the US of death rates versus not test rate, not test positive rates, but death rates we actually see doubling times that are more in the two to three day period, which suggests an R0 that’s maybe five or six and so there’s a lot of question about what exactly is the R0. And in many ways the R0 is a reflection as much of the virus as much as the community that that viruses in. In many ways, it doesn’t make a lot of sense to say this is an R0 for the US because we’re such a heterogeneous country in terms of cities and towns that I think it should be viewed in a much more localized fashion. For example, a rural area somebody over the course of two weeks or a week of being infectious may not come in contact with a huge number of people and that will necessarily limit that person’s ability to spread it to a large number of people versus in New York, somebody at the peak of their infection on the subway could, on average, spread it to very many people so R0 really is a function of environment and the pathogen itself.
Q: Thank you.
MODERATOR: Next question.
Q: Hi, thanks for taking the question. I’m wondering how then we stop this or slow this outbreak in places like Boston and New York, if, the R0 is that high and if we are dependent on subways and mass transit and things like that?
MICHAEL MINA: Well, it definitely poses much more challenge. And that’s why I think you know the more localized the city and in terms of sort of the, the more transmission that can happen as people go to work, I think we have to be more careful about how we open up and how we utilize public transport, there’s a lot of people who have no option so, of course, public transport has to happen, but this is where continuing to wear masks once we open things back up will be crucial. Continuing to be absolutely diligent about washing your hands regularly, keeping alcohol sent hand sanitizer with you regularly. These things will help. They will not completely prevent transmission and in some ways, you know, that’s why I would say that we should really be placing resources into sort of structural changes that could help better prevent infection in the more vulnerable and elderly because we are not going to completely stop transmission of the virus.
And that’s, that’s the whole idea of sort of flattening the curve is we want to just get it to a place where we can at least slow it down in some ways to slow it down or being extraordinarily diligent about just trying your best not to infect other people and that is wearing masks and that is all these hand hygiene measures and maybe trying to change business times so that rush hour, you don’t have everyone, maybe you can actually somehow reduce the density of people who take the T or take the subway during rush hour and have phased sort of work times. So those are those are some ideas that get kicked around along with having surveillance setup, but a goal should really be to assume that transmission will continue. Hopefully that it will continue at lower non-explosive rates and put the resources into protecting the vulnerable people who would ultimately end up in the hospital at higher rates and try to slowly build herd immunity, I think, is one path that we have to become comfortable with and figure out how to do it well.
Q: Hi. Yeah, the structural changes that you’re talking about to protect nursing homes. What, what kinds of thing, can you give some examples of what that would look like?
MICHAEL MINA: Um, well, some of them might be to get, you know, for example, anyone who’s coming into a nursing home. Maybe you have, you end up having testing for anyone new coming into a nursing home on a given day, maybe to enter you actually have to have a viral test done and nursing homes have to be extremely limited. Things like the way that air flows in a building, including in hospitals and nursing homes, you know, maybe I haven’t seen much, but I know that there’s sort of these turnstile doors in a lot of the Northeast that are designed quite literally to trap warm air so that it’s energy efficient, but for these turnstile doors that if they’re designed to trap air, they’re also designed to potentially trap, you know, whatever’s in that area, including potentially viruses. And so, you know, seeing things like that, maybe, those types of entryways of nursing homes need to be reevaluated or hospitals need to be reevaluated in terms of how they’re being used.
So I think there’s, it’s kind of a whole different area. And it’s not a, it’s actually not the structural changes would be, and they get a little bit out of my personal area of expertise, but I feel that there should be concerted sort of changes made to approach these types of policies. The testing is within my realm of expertise and I think we do have things like the Abbott ID now. We’re going to see increased numbers of very rapid, viral diagnostic tests that can be done in a matter of five or ten minutes come out more frequently and that might be a good place, for example, to really focus some of these rapid diagnostics as they become available, put them at the front of the front of a nursing home, and nobody’s allowed to come in for work or to visit, you know, without getting a test on as they walk in to ensure that their negative, those are some pieces that I would suggest.
I unfortunately have to head out to another meeting right now. I thank everyone for their questions.
This concludes the May 4 press conference.
Marc Lipsitch, professor of epidemiology and director of the Center for Communicable Disease Dynamics (April 30, 2020)
Barry Bloom, professor of immunology and infectious diseases and former dean of the school, and Bill Hanage, associate professor of epidemiology (April 29, 2020)