Coronavirus (COVID-19): Press Conference with Caroline Buckee, 06/16/20

You’re listening to a press conference from the Harvard T.H. Chan School of Public Health with Caroline Buckee, associate professor of epidemiology and associate director of the Center for Communicable Disease Dynamics. This call was recorded at 11:30 am Eastern Time on Tuesday, June 16.


MODERATOR: Dr. Buckee, do you have any opening remarks?

CAROLINE BUCKEE: No, I think we should just jump right in and I can answer questions. That seems the most efficient.

MODERATOR: Great. First question.

Q: Hey, thanks very much for doing this. So when you when you look at states that have had roughly similar timing in terms of imposing and lifting stay at home measures, they’re now experiencing different rates of of case increases, in infection increases. What are some of those sort of potential factors that could explain those different experiences?

CAROLINE BUCKEE: So I think that there are a number of things happening. The first is, you know, this country is large and diverse and there are many different underlying risk factors that will determine how many people are symptomatic or need hospitalization or die. So that’s not just age, but also comorbidities, crowding in houses, those kinds of things. So that’s one thing.

The other major thing that kind of determines the trajectory of the infection is population density and mixing patterns and in different places in the US are structured differently with respect to how much people interact normally, as well as the kind of inherent differences in how people are responding to the coronavirus in terms of their fear or lack of fear about mixing in public. So what we’re seeing kind of cultural differences around the country in the extent to which people are deciding to social distance or not, or do hand hygiene or wear masks. And that’s probably going to play an important role, too, in what happens with cases in different areas of the country.

Q: And if I can, just it seems that, you know, some states, I think Arizona, Texas, the Carolinas, they’re already getting behind infections again. Maybe they didn’t quite have the contact tracing system that or I guess adequate contact tracing system set up. Are there ways to sort of get back, get the outbreaks back in control again? Like, without having to impose more distancing or restrictions, that type of those types of things.

CAROLINE BUCKEE: So I would say I’m not sure that there’s anywhere that’s doing contact tracing really aggressively and well right now, across this country anyway. So, yeah, we’re seeing very worrying epidemics happening in places like Arizona. I think that, you know, there is there is a whole spectrum of interventions between no social distancing and normal behavior and complete lockdown.

And, you know, we’re going to have to be quite flexible about making decisions along that spectrum. So when we see surges in cases, then we would may need to roll back and think about putting in place some restrictions on how people are interacting with each other. That doesn’t mean going back into lockdown necessarily. It just means taking a rational approach to how we manage risk as we see spiraling numbers of cases.

MODERATOR: Next question.

Q: Thank you for it for doing this, Caroline. As we look at that spectrum of various non-drug interventions that can be brought in, there seems to be kind of a rising opinion that it could be that wearing masks in public could be the most important one. Actually, Michael Mina said that last Friday, and you probably have seen there’s a bit of controversy about a paper out in PNAS that also seems to be saying that. What is your opinion on whether masking in public is the most important non-drug intervention? And if it is or is one of them, could you comment on how it was just three months ago that the CDC was saying, eh, masking I don’t know, you know, maybe, kind of, probably not. That’s such an incredible flip flop. I mean, I’m not saying it’s a bad thing, science advances, but how do you see that?

CAROLINE BUCKEE: So, first of all, I would just like to say that I think that PNAS paper should be retracted. It is absolutely riddled with errors and would not have got through standard peer review. So that’s the first thing just to say. So what I would say is that the evidence, it’s quite hard to quantify is in a rigorous way exactly what impact masks are having. And, you know, researchers have tried to do that for influenza in the past. Having said that, there are clear, plausible, mechanistic reasons that masks may well be important.

So I think it’s a situation where the, you know, randomized control trial level evidence may not be strong in the literature, however, we believe based on plausible kind of logical arguments, that it might be very effective, so it’s definitely worth doing. I think, though, that there are other things that we know are important, right. And the sort of emerging consensus on that is that it’s, you know, large gatherings crowding together, crowding in in indoor spaces with poor ventilation. And then these like high risk kind of situations in nursing homes, meatpacking factories and so on. Those are things that we really need to continue to avoid. So I think, yes, masks.

And part of that is about and I think part of the reason that that can be successful is that it’s sort of an individual level thing that people can can do themselves to protect people around them. Hand hygiene will continue to be important, social distancing in terms of just staying away from people. But the high risk factors we know are, you know, crowding together, poor ventilation and so on. So I think masks could be very effective. And we need we need rigorous studies to disentangle that. But I think these other these other things are also important, like preventing crowding and and large gatherings, especially indoors and in places that are poorly ventilated.

Q: Thank you. Just a quick follow up. What’s the worst thing about the PNAS paper?

CAROLINE BUCKEE: I don’t even know where to start from. It’s just – have you looked at the figures in the paper?

Q: I haven’t. I just read the abstract.

CAROLINE BUCKEE: So if you – I suggest you take a look at the figures and you should be able to see from that white what’s there are many, many problems with that paper.

Q: OK, thank you.

MODERATOR: Next question.

Q: Hey, thank you so much for doing this. I have a question about the state of Florida because we saw the numbers here – I am in Florida right now – growing lately. So what could be the reason? And what should be done? Because local governments say it’s just because, you know, the number of tests was increased and, you know, a lot of them are positive. What’s your opinion?

CAROLINE BUCKEE: So the first thing to say is that it is true that the number of cases reflects not just how many cases there are in the community, but also testing capacity. So we’ve seen this throughout the epidemic. That testing capacity has constrained our ability to make inferences on the number of cases in a community. And when cases perfectly tracked track testing, obviously we are not actually measuring all of the cases that are happening. Having said that, I think that the uptick in cases in Florida is a real signal and it’s likely that their epidemic is growing. And, you know, that uptick seems to have started towards the end of May. And so I expect that we will see the resulting deaths from those initial infections occurring towards the end of June.

Q: And the second question is, besides Florida, there are a number of states that, you know, the numbers were growing. Do you think that could be the beginning of second wave because everybody was talking about fall? Could that be earlier?

CAROLINE BUCKEE: Yeah, I think we you know, when we speak of waves, that implies that there’s a trough. However, we haven’t really seen a trough. There hasn’t it hasn’t been, you know, cases go up and go down and then go up again. In many places we’ve seen cases go up, maybe come down a little bit, but stay fairly constant. And then with the reopening policies, we’re going to see it surge up again. So whether you classify that as a first wave or a second wave or just a continuation of the kind of middling plateau is sort of an academic argument. You know, we will with the reopening, we will definitely see increasing cases.

Q: Thank you so much.

MODERATOR: Next question.

Q: Hi. Thanks so much for taking my question. My question actually has to do with a little bit with the last one, but I was wondering if you could speak more broadly about a variety of states rather than just Florida. So the idea of, you know, the uptick in cases being related to testing, increased testing, as the administration is now saying. And I guess in addition to that, you know, how concerned should we be about these upticks? Are they large enough to be concerning or are they more or what we expect when we just loosen a little bit?

CAROLINE BUCKEE: So I think if I would repeat what I said for Florida, which is, yes, testing is an issue. So, you know, the general rule is you want to make sure that your cases and testing are tracking perfectly, because that really implies that it’s just testing. However, I think that the signals we’re seeing from across the country are real and they correspond to what we knew would happen when when society started to open up, which is that we get more mixing and we’ll start to see the emergence of the virus spreading again. So I think that those are those are real signals across the country. The question of whether – so the answer is yes, we would expect that to happen because the virus didn’t go away and now we’re reopening and increasing mixing. So we do expect that to happen.

Whether it’s happening too fast or whether it’s happening in an uncontrolled manner is something that policymakers need to decide when they think through their calculation of what they’re willing to tolerate for society to open up and whether their hospitals can can handle the capacity that they’ll need to manage those cases. So those are decisions that come down to policy and what people are willing to tolerate in terms of the health costs in order to understandably address the economic costs of staying locked down.

Q: Great. Thank you.

MODERATOR: Next question.

Q: Hi. Thank you, Nicole and Caroline, for doing this. My question is, you know, across the country and here in Florida where I am, we’re seeing an uptake in COVID positive cases, but not the same level of increase in COVID deaths. Is there a reason for that?

CAROLINE BUCKEE: I suspect in many cases it’s just the time lag. So the cases that happen now will result in deaths in about three weeks. So we think that the time lag between cases and hospitalization is about two weeks and then another week for people to start dying. So generally these time legs can seem fairly lengthy. But in fact, they are as expected. So we’ll see an uptick in cases, and then three weeks later, a month later, we’ll start to see those deaths occurring.

Q: Thank you.

MODERATOR: All right. Next question.

Q: Hi. Thanks so much for doing this. I want to flip the script for a second and ask about a state that appears to be doing well. Colorado seems to have flattened number of cases and a flat R0. I’m curious if you’re noticing anything in the mobility data that would or any other data that suggests why a state that reopened relatively early is doing so much better than neighboring states like Arizona or Utah.

CAROLINE BUCKEE: The short answer is, I don’t know. I have colleagues that are working in Colorado on the mobility data and from what I can remember – maybe I should just put you in touch with them, actually. They would have, because they’ve been working with the governor’s office and they have a sense for how their decision making is working more than I do. I’m happy to do that.

Q: OK. Thank you.

CAROLINE BUCKEE: I don’t want to guess because I’m not sure.

Q: All right. Appreciate it. Thank you.

MODERATOR: Next question.

Q: Hi, thank you, as always, for doing this on. I kind of want to. I’m not sure you’re willing to speculate on this, but there’s been several studies and models out there predicting ultimate potential for for mortality. So my question is, what about a vaccine and without stringent preventive measures, which seems to be where we are now, at least, you know, without more preventive measures than what’s going on today, what number or range of deaths do you expect from this pandemic in the United States going into, you know, 2022? Sorry, I should have sent that one before the call.

CAROLINE BUCKEE: I don’t think I’m willing to to put any numbers on it. There is so much uncertainty. So, you know, here are the things that it depends on in my mind. So first of all, there are hundreds of randomized controlled trials for treatments happening. If some of those treatments prove to be effective, then we can essentially cut those mortality estimates by huge fractions. Right. And so that’s a huge unknown that could make a massive amount of difference.

And then the second huge unknown is the behavioral response to this, both among government agencies and by people. So we know we have an election coming up. We have ongoing protests around the country. We have very different reactions to social distancing interventions that have been implemented in different parts of the country. And all of those things mean that it’s incredibly difficult to predict both the policy that will, how policies will change over that long time period, but also how people will respond to them. And taken together, that makes it incredibly difficult on the timescale that you’re talking about to make sensible predictions about the total death toll.

We have to hope that there are treatments that mean that we can avoid the deaths that we have seen so far. And if we can focus on protecting highly vulnerable communities in nursing homes and incarcerated populations, those strategies will also play a huge role in determining the overall mortality rate from this epidemic. So I’m afraid I can’t give you a number. But the uncertainties and the unknowns, both political, social and scientific, make it very, very challenging to come up with a number that makes any sense.

Q: I appreciate that. And you answered one of my follow up questions regarding nursing homes and targeting nursing homes, meatpacking plants and other places like that is going to be tremendously important. You brought up treatments. Is it possible that treatments could be more important over the next year or so than a vaccine, given the timeline to actually develop and deploy either?

CAROLINE BUCKEE: I think in terms of just possibilities for saving lives, absolutely. Because, you know, there are a number of randomized controlled trials with drugs that are already proven to be safe. So you know there’s a potential for rolling those out and scaling them up much more rapidly than the more difficult challenge of developing a vaccine, showing it works and rolling it out and scaling it. So I think that in the short term, if we find promising treatment, it can be implemented much more quickly. So in that sense, yes.

Q: And I know I recognize this is not your area of expertise, but just to provide us with some leads, do you have ideas of which of these treatments might prove most promising?

CAROLINE BUCKEE: No, I don’t think anyone would be able to to give you a good answer on that.

Q: OK. Thank you.

MODERATOR: All right. This is a question for my email. Hold on a second. And she’s working out a fact check and about a claim from the president that the president made yesterday regarding coronavirus testing. The statement is, if you don’t test, you don’t have any cases. If we stopped testing right now, we’d have very few cases, if any. Do you have any thoughts as to whether or not that is a true statement or how can be fact checked?

CAROLINE BUCKEE: Yes. What I would say is that, you know, if you don’t test anyone, then theoretically, you will find no cases. That doesn’t mean there are no cases. Clearly, there is coronavirus spreading very rapidly around this country. Whether or not you choose to look for them is a separate issue. So is it a fact that if you test nobody, you find no cases? Obviously, yes. Does it reflect anything about where we are with this epidemic? No.

MODERATOR: OK. Thank you. Looks like another question.

Q: You gave me just enough time to to think on this one. So, again, I don’t mean to put you in a corner here, so if this is not a fair question, feel free to sidestep. But I’m wondering if you have in your mind thought of the value in sort of a ranked order between all of these approaches that we might take to controlling ultimately deaths. Right. Between testing, contact tracing, preventive measures and treatments. And I did not mean to rank them as I said them, but I’m curious if you’ve thought about that.

CAROLINE BUCKEE: So I think there’s an important question about timescales there, given that there is some inherent constraints with how quickly we could get a vaccine. I think a vaccine ultimately would be the best preventive measure for the world. But that’s going to take a long time. And there are still questions about the extent of protective immunity and whether we can develop an efficacious vaccine. And so that has to be a priority, but it’s going to take a while.

So in the short term, I think finding treatments is, you know, in the very shortest term, the NPIs have to be – that’s what we have right now. We have non pharmaceutical interventions like social distancing and trying to control contact rates. That’s what’s available to us. In the medium term, some treatments might come online which mean that we still see transmission, but we’re able to reduce morbidity and mortality until a vaccine shows up. In terms of the role of testing and contact tracing, I mean, that’s part of the non pharmaceutical interventions that we have.

I think contact tracing is most effective when you have very low incidence because you can do it more efficiently and you’re aiming for containment rather than transmission reduction, although it can be effective, it can still help in reducing the reproduction number, even if you’re not at a containment phase. So but I think the testing issue is an interesting one, because at the moment there are time lags with testing, there’s continuing issues with testing capacity. And so it’s kind of a necessary but not sufficient tool to get to epidemic control more generally. Right. You need testing, but you need to be able to do something with the data from testing. You need to be able to have a plan for when someone tests positive and have capacity for when and if they need to go to hospital. So I don’t know if a rank, I would say that it’s more of a time scale issue and a sort of utilitarian what’s going to work now, what will hopefully work in the future, and how do these things layer in together? I think they will have to be part of the solution.

Q: Quick follow, since I don’t see any other hands there. When you talk about testing and tracing you, you said something to the effect of that might not be the most effective approach unless you’re talking about small numbers of cases. Are you referring like to rural areas or a small town or a place that hasn’t previously had infection? Does that imply that avoiding large indoor crowds might be more important than the testing and tracing we subsequently do?

CAROLINE BUCKEE: Yeah, well, so containment, I think I would frame containment as, you know, the start of an outbreak, you know, or the remaining last pieces of an outbreak where we’re really trying to nail down and find the index case and who they may have infected so we can stop more widespread transmission. Right. And that is something where, you know, if you think about you, you find one index case and you have to quarantine, say, 10 people. For every index case, if you’re having to quarantine 10 people, you can imagine how that’s difficult to scale when you have many, many cases.

And so just from a practical perspective, contact tracing, testing and contact tracing is really critical when you’re in this phase when there’s not that many cases and you’re trying to stamp out individual chains of transmission once you have widespread community transmission, while it can help to reduce transmission a little bit through those types of approaches, because it’s not hugely scalable, you’re going to need a much more broad approach to social distancing. And then absolutely, you need to do things like no gathering’s and these other kinds of non pharmaceutical interventions if you actually want to bring transmission down to a controllable level. Does that make sense?

Q: Yes, it does. Thank you.

MODERATOR: Next question.

Q: Thank you. I’m still obsessing on masks a little bit just because I still feel mystified by how the accepted wisdom on the efficacy of wearing masks in public went somewhat wrong beforehand, or at least it was being practiced in Asian countries, but not here. Can you get any sense of it, of a historical explanation of why masks were thought not to be valuable to prevent transmission, at least in some circles?

CAROLINE BUCKEE: So I think if you look in the scientific literature, when people have tried to prove that masks are effective to stop the transmission of an airborne virus, the effect sizes that you see are quite small. And sometimes you see perverse outcomes, like people end up touching their face more when they have wear a mask and so on. So I think it’s largely because it’s not like dramatically clear from the scientific literature that masks were definitely going to be an effective piece of the prevention puzzle.

But I think that, you know, there’s now kind of -we think now that we have kind of the transmission routes more widely accepted and a bit more understood, like I said, that the fact that there is plausible mechanistic reasons to think that even though it’s been really hard to measure in the scientific literature, it still may well be an effective way to stop transmission. So I think that, you know, at the beginning of an outbreak, when you really want to use the best evidence in science that you have, that solid scientific foundation wasn’t really there for masks. And the reason that we’ve changed is because, you know, as we learn more about droplet transmission and so on, we think that despite the lack of solid scientific foundation, there are plausible reasons that masks are going to be a good idea. And so it that kind of underpins this shift.

Q: Sorry, last question, but are we looking at empirical reasons why, in fact, masks seem to be effective? Is it that we understand that the virus transmission is different from, say, flu or things that have been studied before? Or what’s the underpinning of the shift? Because those plausible mechanical reasons were always there.

CAROLINE BUCKEE: Yeah. No, I don’t think that, you know, there’s been a lot of debate about aerosol droplets and airborne transmission and so on. I don’t know, actually. I don’t know if I can explain exactly why the shift happened so dramatically. I think that was the original hesitation. It was this kind of absence of solid literature.

Q: Got it. Thank you.

MODERATOR: Next question.

Q: Thanks. Yeah, I have a follow up, a question related to the idea of waves, multiple waves of the of the pandemic. And you had mentioned that, you know, it’s kind of becomes an academic question whether we’re now in a second wave or not in the places that are seeing an uptick in cases. I am fact checking something from someone in the Trump administration, and he was saying that hospitalizations may be going up, but that’s because elective procedures are now permitted. And more importantly, although the case rate has increased, we’re not talking about a second round. So I wanted to ask you about the idea of, you know, I’m assuming this does not preclude us from having a true full surge, second wave like in the fall or something. So I just wanted to clarify that.

CAROLINE BUCKEE: Yeah, I think well, the first thing to say is that these timelines are important. Right. So cases, detecting cases, we expect some significant time lag between that and hospitalizations and deaths. So I think it’s too early to say yet what will happen. We’re seeing this surge in many states and it’s very hard to predict what, you know, I think that there’s no question that we’re going to see surging hospitalizations and deaths in places like Arizona due to that uptick in cases.

And it’s just a matter of waiting for a few weeks. So I don’t – there is there is potentially the idea that we are doing a better job of protecting vulnerable populations and nursing homes. But I haven’t seen really any hard data on that. That doesn’t seem like it could be an explanation. So I suspect that this is all a matter of time lags and that the epidemiology is doing what we expect, which is a significant increase in cases following reopening, and that we will see the hospitalizations and deaths occurring.

As far as the full surge goes, you know, we still don’t really know the extent to which seasonality is going to play an important role here. It seems likely that UV light and, you know, being outdoors is going to potentially reduce, keep transmission somewhat lower than it would be in the winter. What happens in the fall remains to be seen. And I mean, it depends whether people are going back to college and school and things really reopen. But I would suspect that part of those decisions about reopening in the fall will be contingent on what happens over the summer and whether we see really huge spikes in deaths that make policymakers revisit their reopening strategies and change course.

So, you know, again, whether the second wave is now and it’s going to just continue in the fall and grow even bigger or whether we’ll change course, there will be some dampening due to seasonality over the summer, and then the winter months, we see another greater surge that could be classified as a second wave, you know, I don’t know. It’s quite hard to predict, but for sure, the fall and the winter months are something that we should be very concerned about.

Q: OK. And then you mentioned Arizona. Do you have any other states in mind that you are particularly concerned about?

CAROLINE BUCKEE: Texas and Florida and states in the southeast, more generally. I mean, apart from anything else, a lot of those states have a lot of demographic risk factors as well. So the concern is not just the policies and the reopening and spreading of the virus, but also the significant risks of of morbidity and mortality in those populations.

Q: That would be for Latino populations or?

CAROLINE BUCKEE: Well, so some of the risk factors, of course, age in places like Florida. There are a lot of elderly people. There is also a lot of poverty in parts of the southeast. And people living in crowded conditions. And, you know, we know that African-American communities are being hit particularly hard. Diabetes is a risk factor and so on. And so those are all going to mean that we expect more illness and more death from COVID.

Q: Thank you very much.

MODERATOR: Next question.

Q: Just a follow up to my question that I asked before about increasing cases, but at the same rate of deaths. I had the chance of an epidemiologists over in Italy where they’re experiencing the same thing what some of the reasons for that might be. He had a handful of answers, including doctors are identifying the symptoms earlier, they’re better at treating compared to where we were a few months ago. Is that a possibility that we might not, in fact, see a time lag? Because looking at our numbers here in Florida, for example, are cases or positive cases are through the roof spiking. But our deaths have remained the same from April to now to June.

CAROLINE BUCKEE: But the spike in Florida, correct me if I’m wrong, but the spike in Florida really didn’t start going way up until the end of May, right?

Q: So I’m looking at the numbers right now. For example, the week of like April 15th, we had two hundred and eighty and then it slowly increased by about one hundred every single week up until this week, June 10th. But the deaths remain the same around 30 per week.

CAROLINE BUCKEE: Yeah, I think this that it’s still important to just think about this like three to four week time lag, that it may just be slowly ramping up. And the death curves are kind of flattened compared to the case curves as well for various reasons. So I don’t think it’s – I’m not convinced that it isn’t just a time issue. The reasons that it could be that there could be a reduced death rate, for example, this thing of, you know, finding people quicker and so on, that could be a factor.

I don’t think that right now we – you know, we know that the incubation period, we’ve known for a long time, the incubation period is on the order of five days. And so people become symptomatic in five days. And to my knowledge, the time lag between symptom onset and hospitalization has not decreased significantly. And so, I don’t know if catching it earlier, given that there’s no treatment, I’m not sure of catching it earlier is helping. Hospital practice could be improving. And so I guess it would be important to look at whether the duration of hospital stays, is that shortening over time? And I don’t know that. But that would be one indicator that we’re getting better at looking after people and we’re learning how to do that more effectively.

So, I mean, you could look at indicators like that. I haven’t seen any data on that. So to me, the most the most kind of Ockham’s reason, the obvious explanation is just that we haven’t seen the time lag has not really yet been accounted for, but there certainly could be these other these other issues or these are the factors that are improving people’s outcomes. I haven’t seen data on that, but I also haven’t seen any new studies on that either.

Q: Thank you.

MODERATOR: OK. Looks like that may be our last question. Dr. Buckee, do you have any final thoughts before we go?


MODERATOR: Are there any aspects of your research that you would like to share, you’d like people to know about?

CAROLINE BUCKEE: I mean, you know, we continue to work with a network of 50 to 60 researchers around the world on on these mobility data sets. It will be interesting to try and understand how those indicators, which are real time indicators, unlike a lot of these other things, like hospitalizations. It will be interesting to see how those track with the epidemic as we reopen, because I expect a different relationship between mobility and cases in the post first wave world. Just to say that’s what we’re working on.

This concludes the June 16 press conference.