Coronavirus (COVID-19): Press Conference with Yonatan Grad, 06/09/20

You’re listening to a press conference from the Harvard T.H. Chan School of Public Health with Yonatan Grad, the Melvin J. And Geraldine L. Glimcher Assistant Professor of Immunology and Infectious Diseases and a faculty member in the Center for Communicable Disease Dynamics. This call was recorded at 11:30 am Eastern Time on Tuesday, June 9.

Previous press conferences are linked at the bottom of this transcript.


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

YONATAN GRAD: I’ll actually just jump right into questions today, actually.

MODERATOR: OK, great. First question.

Q: Thank you, as always, for doing this. So speaking to one of the topics that you said you wanted to talk about today, it looks like the virus is now spreading into small towns and rural areas and obviously many more locations than several weeks ago when we kind of hit a peak on new cases. So I would just like you to talk about that a bit and what what you see happening in terms of the number of locations of spread where it’s spreading and what that’s going to mean in the coming weeks.

YONATAN GRAD: So I think this gets to a critical point to keep in mind about the pandemic, and that is that we should expect to see spread wherever there are susceptible individuals. The timing of entry will vary depending on what the connections are between communities, but we should expect to see that the virus will go wherever there are susceptible people. So it’s not a surprise that smaller populations, perhaps communities that are less linked to the major metropolitan centers, are seeing kind of somewhat delayed appearance of COVID-19. But it’s not, you know, it’s, again, kind of in keeping with expectation that they will see it, right, or that they are seeing it. It’s just to the point of it being hyper local, once it gets in, we’ll then expect to see spread, but the timing of entry depends on a variety of factors, including the extent of connection to other communities.

Q: OK, so some of the early outbreaks, well, some of the worst early outbreaks obviously were in New York City and other places where you had lots and lots of cases and that drove that initial peak. We’ve got a bit of a trough happening on new cases now as this spreads out into rural areas. What do you see happening over the next few weeks in terms of case count? Are we going to get back up to that level we were at before, maybe get beyond it? Or maybe can we hold steady here?

YONATAN GRAD: Yeah, all of this is really going to depend on what choices each jurisdiction, each community makes about its mitigation efforts. The cumulative, kind of aggregate experience, I should say, the aggregate over the entire country is a reflection of all of the different individual choices that communities are making about their mitigation efforts. So in some places, we’re seeing the decision to lift community lockdown mitigation efforts and we should expect to see to the extent that there remain sufficient susceptible individuals in those populations to sustain epidemics spread, we will start to see a resurgence in some time.

You know, it’s hard to predict exactly when because it’s not clear what the contact patterns will be in those populations, so how much opportunity the virus will have to transmit. But with removal of lockdown in populations where that’s happening, we will start to see a resurgence. Similarly, in those places that are now starting to see their first real outbreaks or their first encounters with COVID-19, the dynamics in those individual places will also depend on what measures they decide to take on for mitigation. And then what we see at the country level, well, at any kind of geographic aggregate, so county, state, region, country, all of that will depend on really what each of these populations are deciding, or is deciding to do for control.

So it’s hard to give an overall forecast. It really depends as it has all the time on community decisions and mitigation efforts and the timing. So one of the lessons we learned again and again is the sooner you initiate mitigation efforts and lockdown, the fewer cases you’ll see in that initial period. You don’t get quite the same burst in cases. So the timing and the nature of the interventions in each of these locations will help shape the experience of the virus. But really, at an aggregate, it’s going to be all of these different experiences put together.

Q: Thank you.


MODERATOR: Next question.

Q: Thank you for doing this. We’re seeing in Massachusetts this baffling picture in which we don’t seem to be using our full testing capacity. And I’m wondering what your analysis is of what’s going on with that. In particular, should we be doing more testing of asymptomatic people? And I think, most importantly, do you have any message for the public about testing and getting tested at this point?

YONATAN GRAD: Yeah, I saw those numbers, too and also was a bit surprised by the extent to which we’re not using all of our testing capacity. And I think that that will be something for both the public and public health authorities to explore more fully. I think that expanded testing and bringing people out to get tested is something that we should figure out how to do. There are particular communities, for example, where we’ve seen from serologic testing that there’s been a large cumulative incidence where, you know, for example, in Chelsea, that was the initial study suggesting a large fraction of the population had antibodies indicating exposure.

Those kinds of populations or others where there are indications the virus spread, those are ones where it would be great to really try to maximize our testing capacity by looking for cases, whether it’s individuals who think they may be exposed or, as you suggest, looking at potentially asymptomatic individuals to try to identify cases. This is also, it seems, a great opportunity for the contact tracing efforts to not only identify cases, but identify their contacts and ideally test them, too. So with the excess or, excuse me. Unused capacity, we should try to think about how to focus efforts on expanding testing or testing ability.

Q: Yeah. But then I guess it at the individual level, would you say to people, and if so, to whom, you should consider getting tested even if you don’t have symptoms?

YONATAN GRAD: Yeah, I think it’s going to be – I would say, I’m curious about what the distribution is of that unused testing capacity across the state. I don’t know how to whether it’s focused in particular communities. So, for example, is it that western Massachusetts has a lot of unused testing capacity or is in other communities or is it evenly distributed? So I want to have a better sense of exactly where testing capacity is not being as heavily used. That would be one piece I’d be interested in.

And then in terms of how to best use it, I think it would be before going to people and saying anyone should come in and get tested, although I hope that eventually we can get there, I’d first want to get a better sense of from hospitalization data, seroprevalence data and other types of surveillance, an understanding of which communities do we consider are right now at highest risk or are likely undergoing cases and use that information to guide where we should expand testing. So it’s not quite something that would be, at least right now, where I could say without knowing more, a blank recommendation, I’d have to – if you’re asking me what I would do, I’d want to know a little bit more before directing particular communities to try to increase testing, including asymptomatic individuals.

Q: Thank you.

MODERATOR: Next question.

Q: Hi. Thanks for doing this. So I know basically the situation in the US right now, and you were kind of getting out this in response to the first question, you know, some areas are seeing cases and hospitalizations go up. Some are seeing them go down. And that’s just probably how it’s going to be for awhile, just like it’s all going to be localized. But I wonder if there’s anything that’s happening now that’s sort of catching your eye or you’re taking particular notice of.

YONATAN GRAD: Well, you know, a lot of my concern is around what’s going to happen next. We are seeing some community see a rise in cases. How are we going to manage the next round of mitigation efforts? It’s still not entirely clear to me whether there’s the political and social will that could sustain another round of community lockdown. So if not, what are we going to do? And as communities start to open up and goes to go through phase one, two, three or four opening, what are going to be the triggers for introducing restrictions again, and which restrictions?

It seems like there’s still work to be done to understand whether we have to return to a community quarantine or whether there are more nuanced, directed interventions that could achieve similar reductions in virus spread. Can we do a better job of our mitigation efforts? Can we design for potentially mediation efforts that are less economically costly but similarly effective in reducing transmission? I think those are some of the challenges still ahead of us. And ones that are going to be increasingly urgent as opening is, we see it in many different places and as people start engaging in more domestic travel, potentially reintroducing virus from different communities. I think we’re going to have to really develop good protocols for both continued surveillance and in response to rising numbers of cases.

Q: And when you’re like, I guess assessing the situation, maybe in a given state or given community even, what are some of the metrics that you would look to like to know if, you know, certain threshold is being reached in terms of maybe new implementation measures or to say that actually things are looking OK?

YONATAN GRAD: Yeah, I think I think that that the ones we would like to keep track of include the numbers of cases. And this gets to Carrie’s question earlier. Can we expand community monitoring for cases widely enough to be able to really get a sense of what the burden of disease is, not just for symptomatic, but asymptomatic or presymptomatic cases too. Then looking at hospitalization rates and looking at ICU use, that I think is is going to continue to be a key measure, particularly as hospitals try to emerge from their surge efforts and return to kind of more standard practice. How much ICU capacity will they have and how much of it is going to be dedicated to COVID-19 patients? So the general community level of disease, hospitalization rates, ICU use rates, deaths as well, understanding where those deaths are occurring. So really having a sense of which populations are being affected.

All of these I think are going to be – if we had dashboards, those would be one important part of it. Another is being able to put that in the context of what has come before. So to know where on the curve are we, or what is our effective reproductive number? So having some sense of how much transmission is taking place. That includes having an understanding of the cumulative incidence so far. So what fraction of a population has been exposed and might have antibodies? Ideally, that confers some kind of protection. But so having an understanding of what the cumulative incidence has been in the population, I think will also be valuable. So if I had my druthers, it would be great to get all of that data really to make the most informed choices on when to introduce mitigation efforts and what kind.

Q: Thank you.

MODERATOR: Next question.

Q: Hi, Yonatan. Thanks again for doing this. Just a follow up in that same area, I’m wondering, are there any specific states that concern you?

YONATAN GRAD: You know, I’d have to check the The New York Times map to look at what the trends have been in cases across various states. I’d say, you know, I worry about all of them, frankly. It continues to be – I think we’re really still in early stages. Well, I would say it’s maybe better to say, you know, we’ve got a long, long way ahead of us. And even places that have been opening up or are starting to open up where they’re seeing a decrease in cases, I worry about seeing resurgence as we start to open up and being prepared to handle that. And then other places where they’re seeing rising cases, you know, what are the what are the responses going to be? Places like Florida, for example, where it seems like over the past few days, I think today it was a little bit less, but for the prior four or five days, new cases were over a thousand each day. And that was the first time, I think, in the pandemic that had been the case. So, yeah, I think every every place has its challenges ahead and those challenges are going to persist for some time.

I think one point here that it’s been brought up regularly is that, again, it seems strange that it is a state by state and that we lack a federal policy and united approach across states. But so it is for now. And that means that really places both individual states and then regions of adjacent states will have to work together as they see whether their first rise in cases or a resurgence after initial declines.

Q: How big a political problem do you think this may be versus a epidemiological and public health problem? Or are the same?

YONATAN GRAD:  I’m no political scientist, so it’s hard for me to speak to the extent to which this is a political problem. But clearly, you know that there is an intersection of politics, economics, social science and public health. All of these forces are swirling around as people try to decide what to do in their communities. From the protests to keep things open, to not wearing masks, to what seems like polarized, a politically polarized response. It’s, you know, there are clearly forces at work in each of these sectors that are shaping responses state by state or community by community. But how much weight each of those sectors has probably varies community by community, but it is certainly playing a role, as we see.

MODERATOR: Next question.

Q: Hi. Thanks. Sort of following up is have you seen any states with a plan on what to do if cases start rising or if there is a second wave, you know, and does that concern you if you haven’t seen anything?

YONATAN GRAD: I haven’t done a diligent read through of every state’s plan, so I can’t speak directly to whatever one is planning to do other than retreat from, you know, start subtracting numbers, right. And go from phase three to phase two or phase two to phase one. But how well those efforts will work and what will happen in those circumstances, I’m not sure we really have a good idea. I haven’t seen much in the way of modeling to be able to tell us that and again what are the triggers for for moving backwards? What is the basis for those triggers?

I think those are all going to be important questions. And again, it’s all key to being able to do sufficient surveillance of the types that I had mentioned before. We’re going to need to have good metrics on the basis of which to make these decisions about re-implementing mitigation efforts of whatever kind and subtracting the numbers from those phases. But yeah. But what exactly the triggers are, how they get determined, and how good our surveillance is in order to be able to have a nimble response I think is is yet to be seen. So I think a lot of this will play out over the next few weeks.

Q: I mean, with the rush to reopen in, do you feel like states might not necessarily be willing to admit that cases are rising and that they might need to hit pause or even go backwards?

YONATAN GRAD: I hope not. I hope that there’s not only an admission, but a recognition. As we’ve seen in some, you know, there were two papers published in Nature yesterday that made an argument for how many lives were saved by these mitigation efforts. I hope there’s a recognition that they’re useful and then it’s really a question of instead of not recognizing cases, trying to figure out a better way to navigate between the public health urgency and the urgency from the economy and others. So really trying to figure out how to not continue to throttle the economy and not see these as in opposition to one another, but figure out a way to navigate through those challenges where, again, perhaps you have more nuanced or directed mitigation efforts.

Q: Thanks.

MODERATOR: Hi. Please go ahead.

Q: I’m just following up on some of these questions about, you know, new mitigation efforts. So there’s been a lot more learned, right, about how this virus spread, you know, close contact, prolonged exposure and spreading events and so on. So I wonder what you think all that suggests for the best way to proceed when cases do start going up again. Do we need widespread lockdowns anymore? Or could they be more targeted? And if so, how?

YONATAN GRAD: Yeah, that’s exactly the right question. I don’t have an answer yet, but that’s what I know many people are working on trying to answer. What are the types of mitigation efforts that were most successful in reducing spread? That’s exactly the question that I think many people are working on, using a variety of different types of data. And then various methods to try to aim for it. And there are still big unanswered questions. What really, for example, is the role of kids in transmission? Could we return kids to school without much in the way of impact? Or is that something that would accelerate transmission?

That seems to me, of course, a critical question, one we would love to be able to answer and through those kinds of efforts really improve the directed mitigation efforts. But I think it’s – I don’t think we have great answers yet. I know a lot of people are working on trying to figure those out. And hopefully we’ll get more information soon. This is a point, actually, that a couple of colleagues and I wrote about in a piece in The Washington Post now months ago, using in some ways the natural experiments that we’ve seen across the country where people instituted different levels of mitigation efforts at different times. We could start to use mobility data from cell phones, for example, to look at how did they change interactions, how did they change mobility, and what impact that had on the number of cases and ultimately the number of deaths in each population. And use these kinds of natural experiments to help learn about what mitigation efforts were most effective. And I think that work continues and hopefully we will learn more. So, for example, that the two Nature papers I mentioned look at the overall lockdown, but hopefully we will start to see work coming out about more directed efforts.

MODERATOR: Next question.

Q: Hi. Thank you so much for taking my question. Your colleagues at Harvard Children’s posted a study in prepress yesterday using satellite imagery to indicate that the outbreak in Wuhan might have started earlier than has been previously suggested. I don’t mean to put you in the awkward position of commenting on your colleagues’ research, but can you talk about what, if any, significance these findings have and how they might be used to help shape our response to the pandemic?

YONATAN GRAD: I haven’t seen that, so I don’t think I can – I have an easy way out of that question because I haven’t actually seen the study, so I don’t think I can comment on it until I had a chance to read it.

Q: OK.


Q: No, that’s OK. Can you talk in general, though, about whether you know why the timing of the start of the outbreak in Wuhan might be important?

YONATAN GRAD: Well, I think it’s, you know, having an understanding of the timing in relation to the cases and the mitigation efforts will help us understand more about what the impact was of this particular mitigation efforts. And again, helping to contribute to the expanding database of which mitigation efforts and of what kinds really had impact, what kind of impact on transmission and the spread of the virus. But, yeah, I would have to – you know, it’s hard for me to say more about what they’re getting at in that study without looking at it. So I would want to get a sense of what they said. But, yeah, it sounds like an intriguing study.

Q: Fair enough. Thank you very much.

MODERATOR: Next question.

YONATAN GRAD: Sorry, who was it at Children’s? I want to just put down my list of things to look at.

MODERATOR: Do you know who the authors were?

Q: I can tell you in a second. Let’s see. Benjamin Rader, Yiyao Barnoon, Lauren Goodwin and John S. Brownstein.

YONATAN GRAD: OK, great. Thank you.

Q: You’re welcome.

YONATAN GRAD: Oh, I see. I’m sorry. Let me just quickly say something. I just looked it up and it says that there may have been spreading as early as August.. One quick comment on that. That’s something I can just very quickly. Without having read the study, I think it would be interesting to see – I need to read it, but, as far as I’m aware, the analysis of the genetics of the virus really put its origins in late fall, so November, December time period. And I believe that was done with fairly good confidence. So it seems like it would run counter to the genetic data to suggest that it was spreading long before then. But again, I’d have to read and see how those two things might, how they try to reconcile those two things. So I think it would just be interesting to try to take one piece of evidence that suggests that the virus really started in late November or December, that’s the genetics, and their observations. So that’s my very first early preliminary impression.

Q: Thank you.

MODERATOR: Next question.

Q: A curveball to you, although I’m hoping you can answer this one. Do you think – what effect do you think summer heat and humidity may or may not have now on this virus, given everything we don’t know yet?

YONATAN GRAD: We still don’t have a great sense of the role of seasonality. In work that we published in Science now a month or so ago, we looked at the seasonality of the common cold causing beta coronaviruses. And it seems like using, again, data from from U.S. surveillance systems, it looks like there was some seasonality where there is more transmission being transmitted more easily in the winter and and there is a diminishment in transmission in the summer. That may still be the case with this coronavirus.

We don’t yet know for sure, but it’s not – I think one important point is even if there is seasonal variation, the extent of that seasonal variation, it’s not an on/off where there is transmission in the winter and there isn’t transmission in the summer. It would even if it impacted transmission and lowered it, there’s still, I think, enough, it’s transmissible enough that we would expect to see spread. And in fact, you know, the rise in cases in Florida should be an indication that certainly this virus can spread in warm, humid climates. So perhaps we’ll have a little bit of a reprieve if there is seasonality and diminished spread in the summer. But it’s certainly not turning off spread, as we can see already happening in Florida and other places. And really, as we knew even months ago when there was spread in Singapore at a time when Singapore had temperatures in the 80s and 90s.

Q: Yeah. Real quick follow, just because I know this will be something people will ask in their heads and can relate to. We’ve seen here in Arizona and elsewhere, flu cases fall off as they usually do, even as coronavirus and COVID-19 cases are rising and we’ve got one hundred degree temperature. So clearly, this is not having a seasonal effect anywhere near what happens with the flu, right?

YONATAN GRAD: There are a couple of things there. So it’s so we know for flu that absolute humidity is a climactic factor that influences its transmission. But with flu, there are also very different numbers of susceptible individuals. Influenza has been spreading through populations for a very long time. And so there is population immunity as well. Whereas for SARS-CoV-2, basically it’s a new pathogen. So there are really, at least in populations that haven’t seen the virus yet, there’s still – and even in those that have – there’s still huge fractions of the population that are totally susceptible. And so that contributes to the effective reproductive number. So for a flu, that would be even that’s decreased by the extensive immunity in the population.

But in the absence of that, we continue to see what we’d expect to see. Less of an impact for four for SARS-CoV-2. But, yes, absolutely. And that gets to another point. The flip side of a decrease in summer, should it be going on, is that we would expect to see an increase once we enter into fall and winter. And that does coincide with when we know influenza season picks up too. Influenza transmission will pick up. And this is one of the things that I think everyone has identified even from the outset, even from that first spread of SARS-CoV-2, as as a point of concern. If we encounter in the fall and winter coincident epidemics of both COVID-19 and influenza, we’re going to have quite a challenge ahead of us. And it is something that, as we think about mitigation efforts for SARS-CoV-2, we have to not only think about what we’re doing for that virus, but also what we can be doing for influenza. And I think this really underscores the importance of expanding to as much as possible influenza vaccination to try to limit the amount of flu that’s going to be in our communities at the same time that those communities will also be dealing with COVID-19.

Q: Excellent. Thank you. That’s some some points that I have not run across before, so very helpful.

MODERATOR: Really quick, going back to what you were talking about with influenza and also the kind of virus. How do those two overlap with symptoms and also with hospitalizations and the resources that they require?

YONATAN GRAD: So the symptoms as respiratory viruses can be somewhat similar. Flu and COVID-19 can cause cough and shortness of breath, fever. COVID-19, has a few additional or different characteristics. The loss of a sense of smell and taste is distinct, so that is one thing that separates them. But in terms of being able to cause severe disease, both seem quite capable. The mortality rates for the two viruses, this has been a point of contention, but it seems, at least for SARS-CoV-2, that we’re seeing infection and fatality rates that are higher than for seasonal influenza. But both are serious respiratory viruses that can cause a large amount of disease and really challenge our health care infrastructure. I mean, you know, when we had flu season in bad flu years, it really taxes the hospitals and other health care providers, so concern about having a bad influenza year together with SARS-CoV-2 when a large part of the population may still remain susceptible and we could see many cases, I think is a possible scenario that is pretty frightening.

MODERATOR: Thank you. Do you have any other comments you’d like to make for today?

YONATAN GRAD: No. Thank you for the good questions.

This concludes the June 9 press conference.

Michael Mina, assistant professor of epidemiology and a faculty member in the Center for Communicable Disease Dynamics (June 8, 2020)

Michael Mina, assistant professor of epidemiology and a faculty member in the Center for Communicable Disease Dynamics (June 5, 2020)

Barry Bloom, professor of immunology and infectious diseases and former dean of the school, and William Hanage, associate professor of epidemiology and faculty member in the Center for Communicable Disease Dynamics (June 3, 2020)