Transcript
You’re listening to a press conference from the Harvard T.H. Chan School of Public Health with Bill Hanage, associate professor of epidemiology and a faculty member in the Center for Communicable Disease Dynamics. This call was recorded at 11:30 am Eastern Time on Wednesday, July 15th.
BILL HANAGE: Morning, everybody. Especially those of you I have not had the opportunity to speak to before. The opening remarks I have are, since I last spoke to you, we have seen the cases that have been building across the South, start to turn, as we predicted, into deaths. This is something we’ve been expecting for some time, but it is obviously sobering to see it actually unfolding in front of you in real time. We’ve also seen large increases in factions elsewhere, notably Brazil. And I think that we are having to watch very, very carefully in order to understand exactly what components of the opportunities that we are giving the virus to transmit are actually the most important. Being able to seal those off is going to be key to keeping a handle on this as we go forward. And with that, which is a very brief introduction, I’m going to hand it over to you and you can ask your questions.
MODERATOR: Great, thank you, Dr. Hanage. All right. First question.
Q: Good morning, Dr. Hanage. Thanks as always. I’m going to ask you one that I’ve asked before, and I know it’s a difficult one. But, to the extent we know more now than we did a while back, how deadly is COVID-19, and how is it compared to influenza and other pandemic diseases that we’ve experienced?
BILL HANAGE: Thanks for that question. I mean, these things are beginning to come into focus now. Very roughly speaking, and there is a caveat to this, which is important, we would expect roughly one in every two hundred infections to lead to death. So that is an infection fatality rate of about point five. That might not sound very high, but it is plenty high enough to kill a very large number of people when you consider that this is a pandemic virus for which there is not really any immunity in the population, and we would expect it to end up infecting a large fraction of the population. Now, the caveat that comes with that, as we all know, and we talk about this a great deal, is that the fatality rate really, really does vary considerably with age. It is enormously more dangerous to people who are elderly or who have comorbidities. The risk of death starts to tick up somewhere around the age of 50, and it gets extremely high over the age of 70. Now, this has been suggested to be relaxed about where large numbers of younger people are getting infected, and we’re probably talking about that later. But obviously, you cannot keep the virus completely contained within those younger, low risk populations. And eventually it gets into the high risk populations and then they start falling ill and dying. Now, for comparison with flu, the infection fatality ratio with flu is about one in a thousand. So, what that would say is that per infection, this virus is about five times as dangerous as flu. I can give you an example of what this means in simple numbers. The population of the city which I live in, Cambridge, Massachusetts, is about 118,000. The number of deaths so far reported from COVID infection here, is, I believe, 97.
So, in other words, that’s almost, not quite, one in every thousand people living in Cambridge. The number of people who have already died from the pandemic in Cambridge is similar to what we’d expect if every single person in the city had been infected with influenza, and illustrates that this is a much more dangerous virus.
Q: And just a quick follow up. Could you talk about the death rate among children and teens in terms of what we know now versus what we thought we knew several months ago?
BILL HANAGE: Sure, the risk of the most serious outcomes, being death in children and teens, is low. It is definitively low. It is not nil, but it is low. The risk of serious illness is also low, but it is higher than the risk of death. So, I mean, no age group gets out of this without risk. And as I’m sure you’re aware, when we start looking at these infections over time, we can see the proportion of them that are very long term or leave people with chronic illness. And potentially, have consequences that we’re only beginning to learn about because this is truly a multi-system disease. We think of it as a respiratory virus, but it infects way, way, way more than simply the respiratory system. And we can expect to see some of those consequences in the health of children going forward. However, the headline rates for the risk of death given infection in those age groups are extremely low.
Q: OK. Thank you very much.
MODERATOR: Next question.
Q: Hi, thanks for doing the call. I just want to know if you can kind of give me your assessment of Latin America, and I’m particularly interested in Mexico. Looks like their death total is now one of the world’s leading totals, higher than Italy’s. What do you know about what’s going on there? Is it Mexico City? Is it border states? And what are the implications for some of the states in the U.S. like Arizona, Texas and California, which are having their own problems? Thank you.
BILL HANAGE: Thanks. I’ll preface this by saying I haven’t made a very close study recently of the situation in Latin America. But what I know of it is that you’re completely correct. This is now becoming another focus of the pandemic. The focus shifts from region to region, and looking at places like Mexico, we are now seeing a very large number of cases there. The implications for border states in general, I think some way to think about this is in terms of when do you care about differences in sort of transmission, when you do care about travel, or movement from one place to another? And you’d care about it when the rates are very different.
So, for instance, if we say that the sort of point prevalence right now is about three in one hundred thousand, for the sake of argument, if I travel to another place where the point prevalence is three in one hundred thousand, then my risk of exposure and my risk in that place is really no different than what it would be here. Moving forward, that’s going to be what’s important. It’s going to be whether or not the risk is actually much higher than the neighboring regions. And of course, you know as well as I do that interpreting the true rate of exposure and the true implications of testing rates is extremely difficult between different states in the US. I think that this is something which bears watching, but I would say that moving forward, just keep a very close eye on it. Does that make sense?
Q: Yeah. And just real quick, I think you mentioned Brazil at the outset of the call. What are your concerns there? How would you assess their situation?
BILL HANAGE: My opinion about the situation Brazil is that it’s extremely grave. We have seen many different nations around the world respond to the pandemic in a fashion which is not really driven by science or public health. Brazil has been a particularly, almost outlier example. And we are now seeing the consequences. It is also very abundant evidence that heat, in terms of climate, is not something which is really going to be our friend and is not going to help the virus go away. As indeed should be the increasing case numbers across the South of the United States.
Q: Thank you.
MODERATOR: Next question.
Q: Yeah, hello. Thank you, Doctor, for doing this. My question is, what could make next winter more dangerous within this pandemic, in your opinion?
BILL HANAGE: Well, the first thing to note is the question of seasonality. Since the very start of the pandemic, there has been the question of whether or not the virus will transmit less well in the summer than it will in the winter. And I have always been skeptical that there will be a big effect because of the fact that we don’t really see it as large, in effect, with other coronaviruses as we do with flu. Flu, there’s a very big effect. However, I have often wondered if there could be an influence over the summer in terms of contact ranks because people make a higher proportion of contacts outside where transmission is less likely. And that seems to be in reasonably plausible. Now, naturally, when you think about the winter, people are going to be making fewer contacts or people are going to be forced inside by the weather. And if people are inside and in contact with each other over a long period of time, the transmission rate is expected to be higher. So in very general terms, whatever we see over the next few months, we can expect there to be an even greater challenge as we move into the colder months. So, the winter is going to be, I would say, really very challenging indeed. And around December, we will start seeing flu season start off as well, and there’ll be other respiratory viruses to contend with.
Q: Just one more, please. Some experts are saying that finding a solution to a pandemic that comes once in a generation in just a year or so is naive. What do you think about that?
BILL HANAGE: Well, to an extent, I think that it is naive to assume that there is a single solution. I think that there is a tendency in some places to believe that there must be some silver bullet that will solve everything. But that’s not the case. I think that what I would recommend is that people stop thinking in terms of reopening and think instead in terms of pandemic management, because they imply quite different things. There are a lot of things that we can do that will slow this virus, which will limit the toll that it exacts on health care and limit in the end, the total number of deaths and severe infections that result. However, in order to do that, we actually have to come up with ways of managing it. We have to take some tough decisions about what parts in a society we are going to prioritize when it comes to allowing transmission to happen within them. So, I think the answer to the question is that it is hard, but it is not impossible. And even the small things that we’re doing make a difference.
Q: Thank you.
MODERATOR: Next question.
Q: Hey. Thank you so much for your time. I have a question about the mortality rate. If we look at the curves, I’m in Florida right now and the spike is obvious, but the mortality and deaths are not spiking in the same manner. I’ve been asking that question, though, a lot of times. And everybody was saying we’ll have to wait for death rates to rise. I recently read an article, and what caught my attention was the quote, “According to CDC, COVID mortality, which had been a decline for last 10 weeks straight, is currently at the epidemic threshold, meaning if it declines just a little more, COVID-19 will no longer be considered an epidemic.” Is that true or not?
BILL HANAGE: I’m not familiar with the article you’re talking about. It doesn’t sound very sensible to me because we can see quite plainly that the amount of disease is increasing in a lot of places and it’s certainly increasing in Florida. A few weeks ago, the cases started to come from Florida, and we have consistently seen an increase in hospitalizations, and we have just recently started seeing an increase in deaths. You’re in Florida, you know better than I do, but I think was more than one hundred and thirty yesterday. I’m remembering this because a few weeks ago, I was thinking about Florida and I was thinking about the fact that, you know, you’d be having around 50 deaths a day continuously and that would just be carrying on. You know, they would be continuing on and on and on for a very long period of time. Instead, as I was expecting, sadly, we have seen the numbers of deaths increasing, and that’s reflecting the fact that the early infections were among younger people and now in older people and those older people are starting to die. Florida is going to see, I don’t know exactly how much, but I would expect the deaths in Florida to be continuing to increase for at least several weeks, even if we were to stop all transmission there right now. So, anybody who tells you that this pandemic is going away or is not really worth taking seriously, I cannot speak for motives, but I can honestly tell you that they are not speaking from a position of science.
Q: Thank you so much. In another question, as you mentioned, the heat, you said that it doesn’t feel like a factor. I’m assuming that it doesn’t affect people because people are getting sick indoors, right? But what about laboratory experiments? Does it affect ultraviolet light?
BILL HANAGE: Oh, yes, you’re right. So, exposure to ultraviolet light and temperatures make the virus less viable, meaning it’s less infectious. But you’re completely correct that that’s not actually what matters. What matters is whether or not it transmits. And this is one of the things which I am unsure of, but I think it is reasonable to suggest this in the category of things which I don’t know is a fact, but which from my knowledge of infectious disease, I am prepared to sort of put out as something which I think is. But as discussion, is the fact that, you know, the summer across the South is the indoor season. It is the point at which, you know, the temperature is such that you’re driven into the air-conditioned spaces. And as a result, people may be making a higher proportion of contact indoors. And that could be fairly important. However, it’s not also the case that, you know, we have large amounts of air conditioning, necessarily, all the places where we’re seeing cases increase. So even though that would be an effect, I’m not sure how large an effect it would be.
Q: And one more question about the vaccine and the cure. Why is everybody talking about vaccine, but not, you know, the actual medicine that heals. What’s the difference?
BILL HANAGE: So the vaccine prevents people from becoming infected in the first place. That’s because it’s stimulating the immune system in order to produce an effective immune response. And that has a great deal of benefit, because what it means is that you do not have to give it to everybody in your population in order to achieve a marked reduction in the transmission of disease. Also, there are a lot of vaccine candidates which are in production, in development, rather, not in production yet. And while we do not know that any of them are going to be working out well, we’re seeing some encouraging data from some of them. When it comes to cures, we have seen various sort of repurposed drugs like remdesivir, which seems to slow or to shorten the course of disease. And that’s not nothing when you think about the fact that you’ve got people in hospital beds. If you can get them off the hospital beds, potentially somebody else can be in there. So it helps, but it’s something which helps the people who are most severely ill. The same thing is true with dexamethasone. Dexamethasone is a steroid, and it’s been shown by a clinical trial conducted in the United Kingdom that it that it helps in severely ill patients. However, it’s not a game changer. We are still going to be seeing large numbers of severe illnesses and deaths as a result of this.
Q: Thank you so much. Thank you.
MODERATOR: Next question.
Q: Hi, Dr. Hanage. How are you doing?
BILL HANAGE: I’m doing good. How are you?
Q: Good, thanks for taking the time. I have just a couple of questions, more local to Massachusetts. The first thing I had, the New York Times has their map of cases throughout the country. We noticed that here in Massachusetts, it had been falling or flat for a while, and just over the last couple of days, it showed a slight uptick. I was wondering if you had seen that or had seen similar data? And if that uptick has been what you’ve seen and if that’s true, what may attribute to that?
BILL HANAGE: So, thanks for the question. And the answer is yes. I’ve been expecting that uptick since probably the end of last week, maybe a little bit before. It tallies with multiple different lines of evidence that are beginning to come in that there is increased rates of transmission in Massachusetts. Now, you’re completely correct in interpreting that. It’s important to note that it is from very low levels. So, this is not at the moment anything, which is, you know, we do not need at this moment to panic. However, I think that it means that we have to ask questions about what the reopening plan is. So, we’ve been proceeding with that. I think that we need to be very cautious about it and we need to perhaps pause at the very least and not replicate the errors of the South by seeing cases start to increase and then persisting, letting the virus get more opportunities for transmission. Because that’s the last thing you want to do. Remember, the longer you leave it to take effective action, the more intense that action needs to be, and the longer it will last, longer you’ll have to have it in place for. So, I think that there is a genuine uptick, and exactly what to attribute that to, I don’t know. But I think that when you start seeing a change in the direction, meaning that the virus is spreading more than it was, then that’s something which you should look very seriously at, and take action.
Q: And just as a follow up to that, going back to your comments about not treating it necessarily as a reopening, but as pandemic management, one of the things here in the state’s reopening plan right now, the phase it’s in, as I’m sure you know, is including allowing some youth sports where there’s not as much contact, like baseball, to come back. In Boston, it started this past weekend, in other places in the state it’s been going on for a couple of weeks. When it comes to youth sports, again, where there may not be as much contact, do you have any thoughts about if that is necessarily something that we should have right now? Or is there any way to make that safe?
BILL HANAGE: Good question. I think that it is both a good question and it also exposes something which is I think is a little bit misleading in the way that we sometimes think about the pandemic, which is sports. They are lower risk for a number of reasons. If they take place outdoors, if they involve children who are less likely to suffer the most severe effects, although perhaps those children could end up transmitting to someone else, but they’d be less likely to infect it if they’re outdoors. So, you could take that to gather and consider it to be perhaps a low risk activity, relatively speaking. But then you have to ask yourself, what are the other risks in the society going on at the same time? So, the amount of transmission from that is likely not very much, but it is going to contribute to the total. What about the amounts of transmission which is happening in people meeting and eating outside restaurants? Or, you know, in restaurants with people dining in? What about the amount of transmission which is happening from workplaces, everything and so on? So, all of these go together. And when they all add up, they are going to result in a final net amount of transmission. And what you want to do is really be thinking about which of those are the most important, and which are compatible with the level of transmission you’re prepared to accept. Does that make sense?
Q: Yes, I think so. Thank you so much.
MODERATOR: Next question.
Q: Good morning. Thanks for taking our questions. I wanted just to go back a minute and talk about the indoor buildings issue. You probably know from Joseph Allen and others that they have been talking about, of course, healthy buildings, but the need to change the indoor ventilation unless it’s already operating at a high efficiency rate to avoid recirculating air that could be, I guess, contaminated with COVID-19. And I’ve seen the Chinese restaurant studies. So, I’m wondering, you know, you mentioned, the winter, of course, people are going to be in the fall, you know, cranking up their heat and being indoors more so. I’m wondering if that should be policy, because, you know, I haven’t really heard anyone say, along with hand hygiene, mask wearing, social distancing, change the ventilation systems. You know, it doesn’t seem to be permeating the policy side of things.
BILL HANAGE: Oh, thanks. That’s a good question. When it comes to details, about ventilation and stuff like that, I defer to Joe because I am more of a straight epidemiologist, if I can think of myself in those terms, not a sort of buildings expert. But I can speak to some of the practical issues that come with ventilation. Firstly, we know the poorly ventilated spaces are a risk factor for transmission. We know that. Secondly, we do not know exactly how that operates. We don’t know exactly what proportion of that is due to the various elements or different droplet sizes. You know, the droplets that contain fluid, which are how the virus mostly gets from one person into another. And the practical issue of ventilation is an important one, but it may be very difficult and extremely costly for some places to be able to put in such ventilation. And, if you think about some of the older buildings, then it may not be particularly practical. So, I think that these are things which have to be weighed on policymakers.
One of the issues which is crucial, which has caused a great deal of discussion recently, including some quotes from me in the Times, is the role of aerosol airborne transmission, which is crucial to this. And while my own feeling is that a proportion of transmission is by that route, I don’t know at the moment how much of it there is. You can be pretty sure that there is not very much of it happening in health care, because we’d see it, these are people that would be able to detect if we were looking for it. However, how much of it is happening in terms of contributing to these super spreader events or things like that, or other opportunities where you have people indoors? That, to me is a more open question. And I think that the ventilation could be very, very relevant to that. So, you know, this is the moment a moving target and we’re still trying to gather data on it. I think that’s as far as I can go right now.
Q: So if I can follow up, you’re saying, there needs to be more studies. You’re kind of aligning with the WHO on that, because that’s what they’re saying. There need to be more studies on those.
BILL HANAGE: Yeah, I think the WHO is in a difficult position. They tend to emphasize the absence of evidence rather than the evidence of absence. So, you know, I would point out that if the majority of aerosol transmission happens from people who are not yet symptomatic, it would be very hard to detect in hospital. So, we have to be very careful when we’re thinking about exactly what the implications are. WHO sticks very close to the data and the science tends to not go very far into interpretation.
Q: Okay. Thank you.
BILL HANAGE: You’re welcome.
MODERATOR: Next question.
Q: Hi, how are you?
BILL HANAGE: I’m as well as can be expected under the circumstances.
Q: Fair enough. So, my question is another Massachusetts specific question. So, cases are rising at a faster rate than what they had seen in the spring, in some states in the country. Obviously, that’s not the case in Massachusetts. You guys are killing it. So what is Massachusetts doing that other states are not, which makes it so successful in keeping these cases down?
BILL HANAGE: So, I mentioned at one point the notion that Massachusetts would be the poster child for the nation. I would also point out that the cases are beginning, in my opinion, to be increasing again. What I think Massachusetts has done well, is implemented a very rigorous testing program, a fairly well-observed shutdown, shelter in place, which took time but was effective. And is hopefully to be avoided going forward but remains to be seen. And then a fairly cautious step by step reopening plan, pandemic management, call it what you will, which is being coupled with careful examination of trying to figure out how much transmission is going on in the community. Now, what will remain to be seen is whether or not that could be sustained because, you know, increases are ticking up now.
The difference between the rates of increase here and elsewhere largely is driven by the fact of when actions are put in place. So, you can think about an epidemic curve. If you put in your shelter in place very early on, then you probably won’t see much of an outbreak at all. If you put it in late, then you’re going to have a longer plateau before it starts to settle down again. And what you’re seeing now in the South, in my opinion, is the consequence of basically giving the virus more opportunities to transmit. So, if you want to stop that, stop giving it the chance. You know, it’s a pretty simple thing to do. The difficult thing with this is that people want to avoid shutdowns. The awkward message that I have to give is that if you reach a certain rate of increase, then that kind of activity, that kind of action is the only thing you have to prevent a big surge into health care, which then ends up damaging health care. The reason why this matters is kind of obvious, but I think I saw a news story this morning in which somebody was saying they had three ICU beds left. Well, they’re going to be filled. And what’s going to happen with the other patients who need an ICU bed then? Because, you know, the pandemic is not the only thing that people get sick from. So, you know, I think pandemic management is the key going forward. And I think to do that, you want to learn from places like here.
Q: Thank you.
BILL HANAGE: Thank you.
MODERATOR: Next question.
Q: Thanks for making the time. I’ve got a quick question that might be a little complicated. So, you know, here in Miami-Dade County, we were one of the first parts of Florida to close down and we were one of the last parts of Florida to start reopening. But our outbreak is still kind of the most severe in this state. So, I’m just wondering how you would reconcile that. You know, we’ve taken stricter measures, but we’re not seeing, you know, any real strong effect from that. So, I guess I just kind of want to leave it open ended and get your thoughts.
BILL HANAGE: Firstly, I didn’t look at Dade recently, so I might ask you a couple of questions to clarify a few issues on it. But what you’re talking about is something which we expect, in fact. So, the initial early shutting down, you know, that’s a key thing and sort of keeping things down for a while. However, then, as you open up, and you give opportunities for the virus to transmit, we start to see something which we have noticed elsewhere across the country, if you look at it writ large, which is variation in the places which sort of get hit hard, quickly. And the reason for that, I don’t know if this is the case in Miami, but you may be able to tell me, are these sort of super spreading events. So a super spreading event is so called because a relatively large amount of people could be infected at one time. And it appears, that this is responsible for a relatively large proportion of transmission in SARS-CoV-2 infections. So, infections are more likely to be clustered. Sometimes very large numbers of people could be infected, as in the hundreds that you have found in association with some outbreaks in bars and alike. Now, what then happens is if you get unlucky and you’ve got a couple of those happening within a relatively small space, it suddenly introduces hundreds of cases to a community very quickly. As opposed to this sort of slow, deterministic build, which means that to get to that sort of number by the sort of steady accumulation would take weeks. But some places are going to be ahead of the curve because of those random events.
Q: So as far as the kind of unleveled field we’re looking at here, what we’re seeing is kind of positivity statewide, maxed out around, you know, 15 to just under 20 percent. But, here in Miami-Dade, when we shot up, we just haven’t been going down. We’re pretty stubbornly stuck over 20 percent no matter how much we test. So, it sounds like that could be at play.
BILL HANAGE: That means the number of cases you’re seeing are actually limited by the number of tests to doing. So, the outbreak could be larger. We saw that across the country in the spring. It sounds now as if that’s a particular problem where you are. I believe this is true as well. Am I correct? I don’t know if maybe your county is a little bit more precise with this, but I sometimes have had trouble disaggregating for Florida the virological tests from the serological tests, you know, the PCR versus the antibody. So does Miami-Dade County report them aggregated or individually?
Q: No. So, they report them individually. And we had a pretty well done countywide serosurvey done in late April, early May. That showed their guesstimate was that about 6.5 percent had been infected at that point. And now people are thinking we might be up near 10, given the kind of the exponential growth of this virus here. But just one thing I was curious to get your response to, another person we talked to about this yesterday suggested that travel and flight patterns could be playing a part in this as well. Because you have such sustained outbreaks in Latin America, and here in Miami we’re kind of the gateway to Latin America, there’s 20 something flights in per day. So, maybe it’s a combination of super spreaders and, you know, a kind of constant seeding from imported cases? Or do you suspect that that might not be playing as big of a role?
BILL HANAGE: So, it depends. So that’s an interesting suggestion. I think it is worth taking seriously, although in order to really figure it out, I’d want to look at flight volume and traveler volume, and when they were coming from. Which you can do, it’s just I’m not aware of anybody who’s done on those data so far. Certainly plausible, it’s certainly worth taking seriously. You can see that, for instance, one of the major reasons why New York City was such an epicenter early on is because there were lots of flights going in there from all over the world, including Europe. So, I think to figure that out, it would be very interesting if we could just get a few sequenced genomes and probably be able to tell you definitively where the virus came to Miami from. But without that, I won’t be able to say more.
Q: Got it. All right. Thanks so much for your time.
BILL HANAGE: You’re welcome.
MODERATOR: Next question.
Q: OK. So, as you probably know, Maine is one of the very rare bright spots in the US right now. Low case counts on our seven-day positivity rate. It’s between one and two percent usually. And we just did another huge testing expansion yesterday. I’m wondering if you could just kind of delineate what you see as some of the reasons Maine is doing well?
And then my follow up is, in this part of the country, it’s outdoor season and tourist season, so we’re getting lots of tourists. But most of our activities are outdoors. Has there been much research, and what do you think about if there are crowds outdoors, I know that’s less dangerous than indoors, but is it still a significant danger to have crowds of people outdoors? And is there research supporting that? Thank you.
BILL HANAGE: So first, yeah, I know Maine well. I understand that is vacation land. So, as I was hearing your question, I was getting a couple of dimensions clear, because one of the things which is important there, is some people may be introducing the virus to the state from other places where it’s at high prevalence. And in fact, I think we’d expect that. The important question is not whether or not it happens, but how much it happens. You’re also right that, as my understanding is and I see reports from folks on the ground in Maine, there’s a reasonable amount of contact, but it is, as you say, outdoors. And while no contact is completely risk free, the risk outdoors is much lower. I would still recommend avoiding large groups of people outdoors and in very close proximity to each other. So, you know, I personally would not be comfortable scheduling any large outdoor music events, for instance, where people would be falling over each other and singing.
The reason why Maine has been in such a good place so far, as several, it’s not a very densely populated state. It didn’t have a large number of introductions. So in that sense, in many ways, it’s quite similar to New Hampshire. And then the actions that were taken, were taken, as I said earlier, at a sufficiently early stage in the epidemic curve. You were not having to chase these kind of transmission chains which were burning like fuses into vulnerable populations. So that’s my read of why Maine has been successful so far. As for what lies ahead, I would expect some introductions from people who have traveled the state from outside with high prevalence. I would expect some more transmission. I would expect that to be ticking up over the summer months, but probably not a very high rate. As you say, the real challenge is going to be when it gets to be cold because Maine gets really cold. And people are then gathering indoors and adjusting to that in the fall and the winter. Depending on what’s been happening in the intervening time, I would expect pretty much everywhere to be worse moving into the fall, in the winter. The only real question is how bad it will be in the summer. And I think that Maine will be somewhat worse than it is now, but probably not a huge amount. Obviously, I may revise my opinion completely based on data that comes in at a time.
Q: Great. Thank you very much.
MODERATOR: OK, great. Next question.
Q: Thanks for taking my question. I wanted to ask about what we know or don’t know about kids and the spread of the disease. I know there’s been some studies that have found that kids are less likely to get the virus. There was this one retrospective study on a primary school in France, that actually found no evidence that kids had transmitted the disease in the school. Are there other strong studies or evidence that kind of back up those ideas? Or is it still very much an open question about how much do kids get this compared to adults, and how likely are they to spread it?
BILL HANAGE: Thanks. That’s a great question. And it’s incredibly important to anybody who has kids in school. I think that if I do another of these next week, and you ask me again, I’ll probably have a slightly more solidified opinion. But I’ll give you my reading of the evidence so far. The difficulty in answering the question is a general one, which is that our ability to observe transmission is altered by the actions that we take and indeed the state of the pandemic outside. So, for instance, a simple example of this. Household studies have typically found that children are rarely infected and rarely transmit. But those household studies all suffer from bias, which is that they start by identifying a person who was infected and then testing the people around them. Now, because children are much less likely to have severe disease or even noticeable symptoms at all, that means that an adult is more likely to be identified as the index case. And then when you go around then and you sample the kids, you find the kid and you assume that the adult must have transmitted to the kid.
The other thing about it is that the closure of schools and other interaction, other actions that people have taken as part of social distancing, limit the opportunity of children to make contacts along which the virus could transmit. So, we’re not seeing the types of interactions that we might expect if schools are opened. We also have to make some very, very clear distinctions between age groups. Because my reading, of the evidence I’ve seen so far, is that younger children are, roughly speaking, about half as likely to become infected, as adults are. Maybe a little bit less likely to transmit, but that’s not as clear of a data point. And then that’s very different when we move to high schoolers. So in high schoolers, and it’s difficult to say exactly what happened in this, but probably whether Israel’s been having trouble with its reopening. They opened the high schools with large class sizes. And then they had a large number of outbreaks linked to schools. It’s very difficult to know whether or not that’s due to the schools themselves or just the schools reflecting what was going on in the community outside.
Now, the best experiment that I’m aware of on this so far is one which is comparing schools and transmission among children in Finland and Sweden. And the reason that matters is because if you look at places like Denmark, which have reopened their schools and with little in fact, so far as we can tell in the pandemic, we have to account for the fact that that’s at the point when the pandemic has way, way, way lower prevalence than it is almost anywhere, certainly in the United States. And that there has been a lot of distancing, your kids are educated in classes which are comparatively small. There are barriers up to prevent transmission, all kinds of things like that.
But Finland has very, very, very little disease. Sweden has had quite a lot. So, comparing the two of them should give you some guidance as to whether or not the children are transmitting in the schools. And it appears like there isn’t a very large difference between the two nations. So, going forward, this is one of the reasons why I think the data on that are going to begin to become available and are going to solidify this substantially. But right now, what I’d say is that almost all the studies that we have about the role of children in transmission suffer from biases of one kind or another. However, it is plausible to think taking a read of all of them together, that younger children are somewhat less likely to become infected and maybe a little less likely to transmit. Older children behave much more like adults, and find social distancing is much more difficult. So that’s slightly older high schoolers and so. So, they should be treated separately.
And then the practical question of comparing what’s happened in different countries and kind of natural experiments that we have, does give us a whole range of useful things. Guidance that we can come up with in order to plan what we’re going to do going forward. Schools in general are really important. I spoke earlier about the kind of cumulative amount of transmission that we are prepared to accept. Schools will contribute to that. You know, any further contact that is there will contribute to more transmission. The question is, how much transmission are you willing to allow? And so you might have to accept that some parts of your economy are going to have to be more closed for longer in order to ensure education to proceed in schools. I don’t think it’s controversial to say that schools are a really important part of our society.
Q: Thank you very much.
MODERATOR: Next question.
Q: Hi. Thanks for being here and taking our questions. So here in the BVI, there has been eight confirmed cases of COVID-19 and one death from the virus. We suspect that both numbers are significantly higher. And to prove that, I’ve been reviewing death records and found that the average number of pneumonia related deaths during March, April and May of this year is three point three. Well, there are one point three deaths per month on average during the previous four-year period. And so, I’m wondering how much significance can be attached to these numbers, given that we have less than twenty-nine thousand residents and a few numbers can skew that dramatically?
BILL HANAGE: Yeah, I see. That’s interesting. People have been doing very similar things for different states in the U.S. And, from what I was saying earlier, deaths are expected in roughly one in two hundred infections. So the fact that you had one death means you have more than eight cases. And so obviously, there is obviously an outbreak of unknown size underlying that, which is larger than is currently being detected. The approach that you’re taking is a respectable one. A more statistical way of doing it is just sort of ask how many would expect given other indicators over the last few years. But I think that it does speak to evidence that there was more transmission, more illness and more death in your, as you say, small community than was originally recognized.
And ask a follow up if you want. I’m actually going to make a note of that as another data point for my own sort of reading of exactly what happened in different places in the spring.
Q: Could you to speak a little more about kind of the approach you’re touching on? What sort of factors would I look at to predict an outbreak?
BILL HANAGE: Yeah. If you want if you really want to do it, then there are ways in which you just kind of try and bottle various other indicators of what you would expect in order to exclude the possibility that some of that variation might be due to, for instance, more flu. You would try and consider the impact of different influences upon the death rate from those numbers. And then, you would have a better estimate of the excess, which would be due to the unknown thing that you have here, which is SARS-CoV-2. I’m going to personally say that if there has been a consistent, very consistent sort of death rate, as you say, that is one point three. You want to consider how much it varies and where from that variation is such that you might be able to get a three point three one year by chance. If it varies a lot, then you can’t say very much. But if it is consistently around that and has been for a very long period of time, then it becomes less likely that these increases could be explained by random factors.
MODERATOR: Next question.
Q: OK. Thanks for taking the call. My question is, are you concerned about the Trump administration’s move to strip control of coronavirus data from the CDC?
BILL HANAGE: Yes. The CDC has more experience in handling data of this kind. More experience interpreting it and more experience, frankly, as an agency of public health. The Trump administration should be working with the CDC, supporting the CDC, and taking the CDC’s advice, rather than anything other than that, pushing back in different directions. So what you’re referring to, I believe, is this data which is going to straight to Health and Human Services?
Q: Yes.
BILL HANAGE: Yeah. The only possible advantage in doing this is that it does enable large amounts of data to be collated in a particular way. And so, for instance, let us consider the successful United Kingdom trial and dexamethasone. The reason why that was able to be done in the United Kingdom is because they do not have a healthcare system which is as sort of fragmented as we have here. And so, they could get very large numbers in order to demonstrate the benefit. So, something similar could be the case here. However, given the extraordinary variation and confusion in testing across the nation, adding a further layer like this to it, which is only going to lead to further confusion and lack of transparency, is a profoundly unhelpful step to take.
Q: And how important is that data to researchers?
BILL HANAGE: It’s incredibly important, it’s everything. Without data that we can be confident in, we will be flying blind. It is bad enough that we have been struggling to keep track of the pandemic through all of the different kind of fog that is in place that we’ve been talking about. We’ve talked about on this call before, trying to understand how many tests are being done, who they’re being done on, what proportion are coming back positive. Are they from the same person? That happens a surprisingly large amount, where you get repeated tests from somebody in order to see if they’ve recovered. And you don’t find out about that. We have to take all of these things into consideration when we’re trying to keep track of what’s going on. And as I say, adding another layer to that and taking it away from the public health agency, which has the most experience in handling it, and which up until recently had a very, very well trusted profile among public health professionals, is a retrograde step.
Q: Thank you very much.
MODERATOR: Next question.
Q: He just actually asked my question.
BILL HANAGE: You can have another one.
Q: My only little follow up is, maybe you can talk about the role of state local governments, their collection of data versus the CDC?
BILL HANAGE: Yeah, I mean, if you actually look at the numbers, remarkably you can find all kinds of confusion among the numbers that are bad. Sometimes what you actually see from a state’s Department of Public Health is not exactly the same as you see somewhere else or that’s been reported to CDC. So there’s a lot of there’s a very great deal of confusion which is going on out there. I mentioned transparency, I mentioned the importance of understanding where the data come from. But what would be really wonderful would be if those states which are really good at testing, and I probably put Massachusetts in that category. And then reporting the data. Sort of share their best practice with others in order to come up with something just comparatively uniform.
You know, thinking of CDC, I mean, a few years ago, I remember there was a call for an application in order to try and come up with a regular data format, which they could use because the different parts of the system have grown organically, which means that some places send in an Excel spreadsheet. Other places send a text file in a different thing. Some places send in handwritten things, some places fax. And this is true from public health, in fact. And what we then we end up with a situation where which any of you can look at in the data, which is that the two days that look like that best for cases and deaths are the weekend. And then the two days, which tend to look worse are at the start of the week. And that’s not because there’s any difference between people getting sick or people dying on the weekend. It’s because of the fact that there are delays of reporting that reflect all these things. Getting that into a uniform format or at least a more coherent format that can be applied to all places will be very helpful on a national level. I know that all makes sense, but it’s just like sometimes people need to say these things.
Q: Right, no, I think our system here is very fragmented. That may move towards uniformity. This seems like a good thing. OK. Thank you.
MODERATOR: And I believe this is our last question.
She would like to know if or when schools reopen for in-person instruction, what is a best practice for if a student or teacher tests positive for COVID-19? Send the whole class home? Quarantine just one class? Keep having everyone else come and simply monitor for symptoms or testing? She also knows that it seems that the CDC guidance is totally absent on this question.
BILL HANAGE: Yes, I agree. I would like the I would like to be more guidance from CDC on this. And I would like that to be guidance that we can all be confident in not being subject to any political pressure. Now, unfortunately, I’m going to have to give a bit of the public health answer that one always gets, which is, it depends. So, there are a couple of things that are helpful in thinking about this. The first, is that whenever you’re testing, you should know what you’re going to do. And that’s what your question points to. And that’s why it’s a good question. The whole point of doing testing is that it’s going to alter testing you’re going to do in the future. And the answer, in your case, depends on the amount of transmission within the community.
So, think of it like this. Imagine you have one case. As I’ve said, this is not even just about kids. The finding of a single case does not necessarily mean that transmission has occurred. So if there’s one case and it’s a single introduction to the school, it’s unlikely, all taken together, to transmit. So under those circumstances, with a low rate of community transmission, it would probably be sensible to shift that group to education at home for a period of time, not necessarily very long, but for a period of time in order to check whether or not transmission had occurred. And that’s very different from a situation in which you are having an introduction into every school, into every class, you know, multiple times. Now, that means one of them is almost certainly going to transmit. The increase in the number of infected people, or potentially infected people, will be much larger. And at that point, the question becomes open as to whether or not the schools should be open at all.
So it depends. I think that if you can keep community transmission low, it’s reasonable to think that schools can reopen. And I think it’s reasonable to think that outbreaks within schools can be fairly readily controlled. Once community transmission gets high and the number of introductions to schools becomes high as well, then you’re in a different situation and you have to start thinking about doing something quite different.
And the only other thing I was going to add is I think it’s helpful to discriminate between three different risks that open schools compose. The first is a risk of transmission to children. Then there is the risk of transmission to caregivers, meaning teachers and parents. And then there is the risk of transmission to the community as a whole. Now, the risks of transmission on children are low. I mean, even if you accept that they transmit and I think they do at a lower rate, but they do transmit, the risk of severe outcome, though not nil, is much lower than for other age groups. When it comes to teachers and caregivers, that, I think, depends very much on whether or not they are in at risk groups. And I think that might be an important thing to keep people informed so that they can think about how to make decisions about how to handle their own sort of health related decisions around risk. That seems one of the really important things about testing and about transparent sharing of information. And then there’s the risk in the community. And that’s the question of whether or not the net force of infection coming in from the community is less than the force coming out.
So, in other words, are the schools a net contributor to the transmission? And I think that at the moment, we don’t have enough data to say whether or not that no under circumstances under which that would be the case. But we do expect it to be the case, the higher community transmission becomes, which is one of the reasons why we should be working hard to think of ways we can limit community transmission.
MODERATOR: OK, great. Thank you, Dr. Hanage. That’s our last question. Do you have any final thoughts before we end the call?
BILL HANAGE: No, I don’t. Thank you to everybody for all your questions and for the work you’re doing covering the pandemic.
This concludes the July 15th press conference.