Webinar: Weekly COVID-19 Pandemic Briefing

Emma Ross

Hello everybody, and welcome to the first in a weekly series of ‘In Conversation With’ interactive webinars with Chatham House Distinguished Fellow David Heymann. Each week the discussion will be guided by the latest developments, lingering issues, as well as questions from our members. This briefing is on the record. Some of you have already sent questions in, and we’ve clocked those, but further questions can be submitted throughout the session using the Q&A function. Please don’t use the ‘Chat’ or the ‘Raise Your Hands’ function in Zoom, but use the Q&A function. So, I’m going to start by asking a few questions, and then I’ll swiftly open the forum to take a selection of questions from those tuning in.

So I’m very pleased to have with us today Professor David Heymann, who, as many of you know, is a world-leading expert on outbreak control. He chairs the independent expert panel that advises the WHO on infectious hazards, including this one, and as Head of WHO’s Communicable Diseases Division, he led the global co-ordination of the shutdown of the SARS outbreak in 2003. So, I’m going to go on to start the questions now, and please continue submitting questions, using the Q&A function, whenever you would like to.

So, David, thanks for being with us this morning. This has got a lot worse since we’d last had one of these sessions, and been characterised as a pandemic for some time now. And it’s accelerating, i.e. it took 67 days for us to reach the first 100,000 cases, 11 days for the second 100,000, and just four days to get from 200,000 to 300,000, and we’re now at nearly 373,000 cases worldwide and more than 16,000 deaths. Dr Tedros, the WHO Director-General, is still saying that we can change the trajectory. But can this really be turned back, and even if we can turn it back, can it be beaten now? What is it going to take, at this point, in terms of national action, international co-operation, and population-level action?

Professor David Heymann CBE

Well, Emma, what we saw first in this pandemic was an outbreak in China, which was circumscribed by a lockdown procedure, and then, other cases that escaped from that area and went into other parts of China or into the world in general, seeded the epidemic. At that point in time, when China had this very aggressive and rapid action, it was thought that possibly this virus could be eliminated from human populations, as was the SARS virus. In the end, though, what we’ve seen is that the lockdown has been very effective in delaying the international spread. They’ve actually stopped international flights out of the province where the outbreak began, and therefore, slowed down the international spread. But it was already out of the box, and it already spread widely by the time China was able to do this. So what we’re seeing now is that it cannot be locked down and cannot be dealt with the same way as the SARS virus was dealt with and stopped. It will continue to spread, and the question is, to what extent, and how long will it continue to spread?

Emma Ross

So, when you say it can’t, we can’t stop it spreading, does that mean we will not be able to beat it? It’s with us to stay as another infection in the human populations?

Professor David Heymann CBE

Nobody can really say that for sure. In the past, there have been coronaviruses that entered human populations, and have remained with those populations causing the common cold. This undoubtedly occurred at a different time in history, when there wasn’t the globalisation that there is today, when the spread wasn’t quite so rapid. But the coronaviruses did spread wherever they emerged, from animals to humans; they did spread then around the world and are a cause of common cold. But this virus has very dramatically hopped on the runway and spread around the world, and it’s now causing outbreaks in most countries in the world. And the question is, what is the destiny of this virus? Will it die out, will it continue to transmit? Will it become like influenza, certain influenza strains, which return each year to cause a seasonal outbreak? No-one knows for sure, even whether this virus will slow down transmission, as people begin to move outside of closed areas into the open summer weather. Because other viruses do decrease in transmission, but the question is, will this virus do that?

Emma Ross

So is – what is everybody trying to do now? I guess the countries that can stay in containment are doing that, but is everybody else just trying to lessen the burden on their health system and keep within their health system capacity? Is that what everybody is trying to do, or is there more variation than that?

Professor David Heymann CBE

Quite a bit of variation in the responses. For example, the response in Asia, in countries where there was previously an outbreak of SARS and MERS coronavirus, that includes Singapore, Hong Kong and South Korea, they’ve had a very different way of approaching this than have countries in Europe and now in North America. In Asia, they learned the lessons from the SARS outbreak, and actually increased their hospital bed capacity and their capacity of ventilators, so they’re able to deal with patients much more effectively, because they have this excess hospital surge capacity. But in addition, they’ve dealt with these things differently. Singapore has tried to keep business going on as usual. They haven’t closed schools, but what they’ve done is, they’ve done extensive outbreak management and control in the initial outbreaks.

In South Korea, where there were many outbreaks, it started from two major outbreaks in church association, people associating in churches. They’ve been able, by increased testing, to identify many persons infected, and by so doing, isolating them and stopping further chains of transmission, and they’re having an impact. But all these countries have excess hospital beds, which they feel can accommodate the patients that are occurring. In Europe, the picture is different, as we’ve seen in Italy. Hospitals have not been able to accommodate all the patients in Italy, and there’s been an excess of mortality, of death, in persons who have coronavirus. But that’s also occurred because the population in Italy is much older than populations in Asia, and there are many people with many comorbidities that are an increased risk factor for death. So, other countries in Europe and North America are attempting to flatten the arrival of these many, many cases, so that hospitals can, in fact, accommodate them, and are at the same time ramping up the capacities in their hospitals and elsewhere to do so. The UK, for example, has made an alliance between the NHS, the National Health Service, and private hospitals to have increased beds and increased ventilators. And countries like Sweden are doing less aggressive measures because they feel they have the capacity to deal with cases, should they occur.

Emma Ross

That’s great, thanks. But should there not be a bit of an attempt to build more beds? I mean, why can’t we just match what Asia’s doing and create massive – I mean, the UK is creating a new hospital in the Docklands, but why is that not more of a strategy: to increase the capacity, to take more if we know what’s coming, rather than try and squash it to fit the capacity that’s already there?

Professor David Heymann CBE

Well, it is important to increase the capacity because we don’t know exactly how well this can be flattened by all the measures that are being taken and each country has a different approach to doing this. But the reason that that the Asian countries are ahead is because they learned the lessons from the SARS outbreak, and they developed this capacity before this outbreak occurred. So they have the excess capacity, which many countries in Europe and in North America don’t have.

Emma Ross

Okay. I’m going to move on now to global-level co-ordination. Dr Tedros said on Monday that he’s going to look for political co-ordination at the international level when he addresses the G20 tomorrow, and he says what’s needed is political solidarity and leadership. What does that actually mean? What should that look like? I mean, we know that each country has to form its response, according to its own risk assessment and its resources and its own customs, and we’ve seen the differences between countries. But are there certain responses that have to be done by all if we’re to beat this globally? Couldn’t one weak link make the rest of the world vulnerable? So, what should the ask be?

Professor David Heymann CBE

Thanks, Emma. You know, a co-ordinated response at the start, a co-ordinated lockdown throughout the world, might have done, had a – made the virus have a different course than it has now. No-one will ever know. But what’s clear is that the industrial sector and the private sectors need to be working together with governments now that there has been a lockdown. And in unlocking, they’ll need to identify which areas can be unlocked first, because they’re of less risk to increasing the number of patients. And that’s a study that has to be done by the public health community, by academic experts, and also, by industry itself. So, closer links between industry and governments will serve us all very well, as we move forward, and hopefully in the future. And I know the World Economic Forum is regularly meeting with industry to discuss various issues. And I’ve been meeting with the WHO group, the STAG-Infectious Hazards Group, which is the advisory group to the emergencies programme that’s running the global outbreak response. And that programme is beginning to develop, with input from external advisors, the strategies that countries should consider, as they begin to remove these very rigid and strong precautionary measures.

Emma Ross

Okay. Can I turn now to the exit strategy? So, what’s going on with the thinking about lifting restrictions? I mean, could we be in a on-off cycle of restrictions until we get back to being able to contain and test and contact-trace and break the chains of transmission ‘til we stamp it out? Or are we going to have to, as some experts are suggesting, keep this – keep doing this rigorously for at least another year until we have a viable vaccine or some other technological saviour? I mean, what’s the thinking about what – where to go next with this? What strategies are being discussed?

Professor David Heymann CBE

Well, the focus is on China, because China is now beginning to unlock certain sectors, including the industrial sector, and they’re doing this very cautiously to see what happens. They have a very low level of cases in the Hubei province, where the outbreak began. At least they have – these are symptomatic cases in that area, and they’re watching to see what happens. At the same time, WHO is establishing, first of all, a set of criteria, which countries might want to adhere to, as they begin to remove some of their precautionary measures. That is, a mechanism to respond to individual cases, should they be imported, and a whole series of other activities, and at the same time recommending that this unlocking process be done by a national risk assessment, identifying which areas are the most common areas that are seeding the outbreak at present, and unlocking those last.

Emma Ross

Okay. There’s a question here from an audience member, Julius Bottcher on that. Specifically, “Are leaders too optimistic that we can beat this virus with a single three-to four-week lockdown?” I guess, means turn it around. Can you comment on the three-to four-week promises, and we’re seeing from Trump also that expectations that maybe parts of America can get back to normal by Easter. Are these realistic?

Professor David Heymann CBE

These are hopes by the Politicians, and unfortunately nobody can say whether or not three or four weeks is effective in doing what is being attempted to do, that is, to flatten the curve, flatten the number of people going into hospital care. But what’s clear is there are a bunch of other – many other activities as well that are going on. I think elderly people everywhere now understand the importance of self-isolation for themselves. And at the same time, others understand that they can prevent infection by social distancing and physical distancing, which means not attending public gatherings, and at the same time, maintaining a distance of about a metre and a half between each other, stopping the customs of close contact that we’ve had in the past. And at the same time, understanding that they can prevent others from getting infected by wearing a mask, should they be coughing or sneezing. So these are other measures that are ongoing at the same time that the forced measures of locking down industry, locking down public gatherings are going on, and no-one can predict what all these will be doing together. It would be nice to be able to do that, but no-one can do that. So what will happen is, after the two or three weeks that governments have agreed to a lockdown, they will reassess, do another risk assessment, and see where they stand and make further recommendations at that time. But this is not a process, which can be an on-off process. We can’t be sure that after three weeks everything will be back to normal, because it will not be.

Emma Ross

Okay and if it turns out that once restrictions are lifted it comes back and the expectation – well, first of all, can we expect that it probably will come back, as long as there’s some virus out there?

Professor David Heymann CBE

Nobody can say probability with – probable with a new virus.

Emma Ross

Okay.

Professor David Heymann CBE

All we can say is that we hope that we can deal with this virus in a way that doesn’t cause increased – the increases in mortality which it’s causing now. So we can’t assess the destiny of this virus. It has its own characteristics, its own way of transmitting to people and then, from person-to-person, and no-one can really determine whether or not that can be stopped at this point. And if it can be stopped, when it could be stopped.

Emma Ross

Okay. So it’s – is it wise to rely on a vaccine to save us?

Professor David Heymann CBE

Well, it would be nice to say there’s a vaccine that could protect against this infection, but there are many issues going on right now that say that this vaccine will probably not be available and licensed at least until the end of this year or early next year. First of all, in vaccine development there must be a vaccine candidate that’s developed. Some vaccines are using the virus to develop a vaccine. Some are using what’s called virus-like particles, which are copies of the virus, parts that are felt to be important in immunity. Those vaccines are now being developed over 30 vaccines and there’s a group in London, the Coalition on Epidemic Preparedness and Innovations, CEPI, which is masterminding all the different trials and providing resources to small biotechs who are doing these trials. When a vaccine is developed, the usual pathway goes first through animal models, to determine whether the vaccine that has been developed is safe and effective in animals. And until recently, we didn’t have an animal model, but now we do, so there’s been great progress in that aspect. There is an animal model, the macaque monkey, which can be infected as are humans infected, and manifest the disease, after a certain period of time. So vaccines can be tried in this animal model.

If they’re shown to be effective and safe in animals, then they go on to trials in humans, which take a longer period of time. First safety trials, and then effectiveness trials, to see whether or not that vaccine is effective, compared to a group of people who haven’t had that vaccine. Once all those studies are done, there’s then licensing done at a regulatory agency, and after that there will be a need for production capacity of that vaccine in the world. Right now, production capacity for a pandemic vaccine such as influenza is about two billion doses. That’s clearly not enough to satisfy the needs of the whole world, should this vaccine be needed.

Emma Ross

Okay. Just one follow-up on that is, can this be eliminated without a vaccine, if we don’t get one?

Professor David Heymann CBE

Well let me finish a little bit about – excuse me – let me finish a little bit about the vaccine. Because if the vaccine is finally produced, then we can have access, hopefully, at least in some countries, or to some populations. But it’s not sure that that vaccine will ever be effective. It’s hoped there will be an effective vaccine, but we don’t know how long immunity might last, after vaccination at this point, and would it need to be given again? But what’s good news is that all of these processes, which are normally done linearly, are now being done in parallel, so we’re seeing that there is already work to find production capacity and a whole series of other things, including early work with regulatory agencies. So that’s a positive, to finish up on the vaccine issues.

Whether or not individual activities can do a lot to stop this, we don’t really know. What we do know is that if persons understand how to protect themselves and protect others, they go a long way to making sure that there’s a decreased transmission of this virus. But over time, if the virus does continue to circulate, it will gradually affect all people, and they will have various manifestations of disease.

Emma Ross

Okay. I’m going to ask my last question before opening it up now, and that’s about reinsertion of the recovered. People who have recovered, had the infection and recovered, does it mean they can wander round safely or even help on the frontlines, without fear of reinfection, or spread? And when do we start using them, how do we know they’re safe? What discussions are going on around this, and are those discussions being co-ordinated internationally, or is each country kind of going their own way with this?

Professor David Heymann CBE

Well, the problem that we have right now is that there’s no validated test to look for antibodies that are specific to this coronavirus. There are many tests that have been developed, and there are many tests which are now being validated. And validated means to make sure that they identify this coronavirus and not other coronaviruses and mislead understanding of who’s immune and who’s not to the current COVID-19-causing coronavirus. So those tests are available, they’re being validated, and they’re on the market already, some of them even though they’re not yet validated. Once there is a good, reliable, validated test then it could be used to test people who think they’ve had coronavirus infection, or who have been known to have coronavirus infection, to see if they have antibody in their blood. If they have that antibody, then most people believe that it will protect at least for a short while, and that these people could safely be reinserted into society. But the problem is, we don’t know how long those antibodies will actually last.

Emma Ross

Okay. I have a question – I’m going to take questions now, so please keep submitting your questions. Which function was it for the questions? It was – not through the ‘Chat’ or the ‘Raised Hands’, but through the Q&A function. Thanks very much. So, I’m going to start with one from – there are several questions about how – you know, fomite transmission, surfaces that can transmit the virus. This is one from Audrey Wells. “Are coins and banknotes vectors for COVID-19? If so, how long will the virus last on them? I understand China has withdrawn and sanitised banknotes from heavily-infected regions. Should the UK do the same?”

Professor David Heymann CBE

Well, the studies are going on now to determine how long this virus really can last in the environment, in fomites, in droplets, land on surfaces. And it’s not yet clear, but it’s thought that it can last possibly up to 72 hours, especially on surfaces that are plastic. So, beginning to understand how long fomites will remain infectious. What governments are recommending is that people wash their hands regularly, because hand-washing will then permit the hands to be clean, if you touch your face and if you should contaminate yourself either through your nose, your mouth or your eyes. So what’s very important is hand-washing. Governments will decide what other measures they need to take. But just in the household, if there’s someone sick, who’s coughing and sneezing, it’s important to clean those surfaces regularly that are near that patient because those fomites can create from the droplets that are coughed out or sneezed out by a person who is infected or who has signs and symptoms. So hand-washing is the key factor to this, and if hand-washing is done properly and often enough, it should be able to prevent people from self-infecting themselves, if they’ve touched a surface which is contaminated.

Emma Ross

Okay, thank you. Here’s a question from Charles Bray asking, “Can you explain the very significant difference in the mortality rates between Germany and Italy, Spain?”

Professor David Heymann CBE

I think those mortality rates are being explained by the experts in those countries as the capacity of the hospitals to deal with the people who are infected, and also, the population pyramid and the age pyramid of populations in those societies. Spain and Italy have about 20-25% populations over 60 years of age, which is much different than it is in other parts of the world, including Africa and in Asia. And so elderly populations, especially those who have comorbidities such as high blood pressure, such as diabetes, such as lung disease, are those at greatest risk. What’s happening is there are more people in those countries who are at risk of getting serious illness. They’re getting serious illness, and we understand that hospitals have not been able to cope with all the people who have required health support, respiratory support, in particular, using ventilators.

In Germany, they’ve been able to space out their serious illness by an aggressive approach to contact-tracing and identifying people, isolating those people. And they’ve been able to accommodate their populations, which are also quite elderly, and do have comorbidities. But what’s very important in all countries is for the elderly to understand that they’re at risk, and for their family members to respect that. And if they’re sick, to somehow isolate from those elderly family members, if they’re in the same household and certainly not to visit them, in facilities where they might be in nursing or in constant care.

Emma Ross

We’ve got quite a lot of questions on the balance between protecting the economy and protecting people, especially in regards to what’s been said by President Trump recently. A flavour of this is David Ricarte, “Given the current information available and the progress in spread, is there a time that will arrive when governments will have to save their economies rather than their people?” And another question, “What, if any, concerns do you have with the US responses and its ability to cope with the outbreak?” from Daniel Sholey and that – those two put together. Basically, the strategy of balancing economy versus health.

Professor David Heymann CBE

Well, it’s a worry of all Politicians, and a worry of us all, really, because what will happen is, those people who are on the borderline of being able to sustain themselves on a weekly or monthly basis by working in smaller-type jobs, will no longer be able to have those jobs, and they will be suffering first. So governments are very worried about that. They’re worried a lot about – about a lot of different issues, and it remains to be seen what they will do. There have been various approaches taken.

In Asia, in Singapore, they’ve not shut down a lot of the different industries, although recently, they’ve shut down public gathering-places such as pubs and cinemas. But they’ve been trying to do this by maintaining a reasonable semblance of interaction of the private and public sectors, of the production capacity within the country. Other countries have locked down these measures and are considering how they might unlock them. China, most recently, has begun to unlock its industrial sector, and we’ll see what happens there. I don’t like to comment on different strategies by different countries, because every country, just as the World Health Organization, is building the ship as it sails. And many new ways of trying to lock down this virus and prolong the rush and the surge on hospitals are being done, and the jury is still out as to which ones of those are most important. What we need to do is hope that our governments are speaking with the public health community, with the academic community, being transparent in these discussions, and working closely with industry and other sectors to decide when is the most appropriate time to unlock.

Emma Ross

Okay. Sorry. A question – sorry, I should have done ‘that’ not ‘that’. A question from Tiafana Cranina, “Could our immune response be affected due to the lockdown? Will it be better or weaker?”

Professor David Heymann CBE

Well, certainly during the lockdown, people need to keep up physical exercise somehow, depending on what the state – what the requirements is where they have been self-isolating or isolating. And exercise is very important in keeping us fit. Whether or not confinement damages the immune system, it’s not really – I don’t know that there have ever been studies to show whether or not this is true. But it would not, I believe, by most Immunologists, be a factor that they would be worried about for the immune system. The immune system depends on the nutrition of a person, on the way that the person conducts his or her life, the risk factors that he or she takes. For example, smoking is a very bad indicator of what might happen in your immune system, because in some ways, it damages the immune system and our resistance to infections in the lungs and also, to infectious, or to other diseases, including cancer. So the risk factors are more important, the risk factors that we submit ourselves to in our lifestyle are really more important than is the fact that we’re confined.

Emma Ross

Okay. I have one from Nicole Carr, who is asking, “Do you think that COVID-19 will mean a change to how we organise and resource healthcare going forward?”

Professor David Heymann CBE

Well, I would certainly hope that it will be a warning and that this warning will be heeded. But there have been many warnings in the past, and those warnings have not led, in many countries, to the strengthening that’s needed to deal with a surge of patients, such as we’re seeing now with this coronavirus. So hopefully, the world will have learned many new lessons, including lessons such as this, where we’re now communicating on an internet platform, rather than travelling to one site, avoiding that damage that we might be doing to the environment by that travel. So I think there will be many new ways of working that will be adopted. I hope so, at least, after this outbreak has finally been completely contained or has been accepted, and we’ve moved on to better understanding of how we can prevent these events in the future.

Emma Ross

Okay. There are a lot of questions here about evaluating specific country responses, and I know you prefer not to get into that, so I’m going to take a science-y one from Dr Judy MacArthur Clark. “I’ve only recently started hearing suggestions to use hyper-immune serum plasma as treatment for those at risk who contract the virus. This seems such an obvious approach, so why has it apparently taken so long to adopt?”

Professor David Heymann CBE

Well, you know, that’s a very good question, and there is work going on in China, and there’s work going on in the UK and in other countries, to collect the serum from patients who have been survivors and then to use the antibody in that serum as a possible means of either preventing serious illness, once a person is infected, or actually preventing infection in households that are at high risk. So that’s the strategy that could be used. That strategy is used, for example, in preventing hepatitis A, if persons aren’t vaccinated, in the prophylaxis being used after a person is bit by a rabid dog, and in many other ways, have antibodies been used in the past. At present, countries are beginning to collect convalescent sera by a process called plasmapheresis, to concentrate that and to see if that might be effective in preventing or modifying the disease course. But it must be used early in infection, or before infection has occurred.

There are also small biotechs, which are working on monoclonal antibodies, which are antibodies that can be created in the laboratory and which can be used also, hopefully, to modify the course of infection. So there is work going on, on that. It hasn’t been used as – it hasn’t been started as rapidly as some would have hoped, but it is healthy now, it has begun, and there will be clinical trials to see whether this is an effective approach, in addition to the trials that are going on with drugs.

Emma Ross

Okay, I will move on. There are quite a few questions, several, on pets and animals, basically boiling down to, “Can pets, such as cats, dogs and other animals, carry or transmit, including if somebody infected strokes the dog, and then can it – does it become a fomite?”

Professor David Heymann CBE

Well, all those are possibilities. We know that there was one dog that appeared to be infected in Hong Kong, but that infection didn’t last a long time in that dog. The dog was rapidly recovered. It was never sick; it just was found to be carrying the virus. It’s clearly possibly that fomites could contaminate the fur of a dog, or of a domestic pet, and it can also contaminate – fomites can contaminate surfaces in that household. So it’s wise to be prudent, to understand that hand-washing is the best way to prevent contamination of a person by washing those hands and abstaining from touching the face.

Emma Ross

Okay, we still have time for a bit more. There’s one on gender differences, and this is from Hannah Devlin, “Why are we seeing higher mortality rates in men versus women in China, Italy and other countries? Are there known biological reasons why men tend to be more vulnerable to coronavirus?”

Professor David Heymann CBE

Well, it doesn’t appear that there are any biological reasons, but certainly there are risk factors that make a person more susceptible to any viral infection, and they’re beginning to link the number of male cases with smoking in China as one risk factor. Because there’s heavy smoking among males and less smoking among females, and that’s one risk factor that they’re investigating as a possible cause for the increased, or apparent increased, susceptibility of males to infection. There’s also work going on in Italy and in other countries to see whether or not this is indeed a risk factor. And recently, the World Health Organization has placed on its website that smoking may be a risk factor to increased susceptibility to infection with this coronavirus, as it is for many other infectious diseases.

Emma Ross

Okay. I’m going to go – the most upvoted question at the moment is, “Could you please comment on the article in the FT yesterday on the study at Oxford University on the number of infections in the UK?”

Professor David Heymann CBE

Well, there’s actually been a lot of discussion about that study, and it’s important to remember that modellers and their models are only as good as the information they put into them. Because models depend on a series of issues, such as the transmissibility of a virus, and in this case, transmissibility is not completely understood. It also depends on the proximity of people to one another, their willingness to social and physical distance from each other, and a whole series of other factors that go into a model. These are assumptions made by modellers and the information they put out are estimates, based on what they put into their model.

What’s important to understand is that models are used by the public health community to see what the worst-and best-case scenario might be, and they were never intended to be used by the public as a means of gauging what’s happening in the population in that country. No-one knows, until they begin more extensive examination of people who might have had infection by using antibody tests, what the actual spread of this virus really is. So modellers sometimes put out estimates, which are a maximum. They also put out minimum estimates, as to what might happen if control measures are well, but the international community and the national communities and, many times, the media prefer to take that maximum number rather than the minimum number.

Emma Ross

Okay. Here’s a question on mutation, from James Barnes, “Do we understand much about how this virus is mutating? How does this affect the global response and vaccine development, as well as impacting on how long a recovered person might be immune?”

Professor David Heymann CBE

Well, it’s early to tell whether or not this virus is mutating with any regularity. What’s clear, from a series of over 300 viruses, for which the sequences are known, have been stored in a data platform called GISAID, G-I-S-A-I-D. This data platform is regularly analysing the genetic information that comes in, and it’s clear that this virus does drift genetically, that it mutates slightly over time. Those mutations, though, have never been linked with the virulence of the virus, that is, its ability to cause disease. Nor have they been linked with the transmissibility of that vi – of the virus, that is, the ability of the virus to spread between humans.

What we do know is that other viruses do drift regularly, such as seasonal influenza viruses, and as they drift, they cause new requirements for vaccines, which are made from the virus. What vaccine manufacturers will try to be doing now is to identify, from these data that are coming in on sequence, where there are areas of the virus that are constant, which don’t mutate regularly, and which may be a target for vaccines or for drug development, so that they’re sure that the vaccines will be effective, over the long-term, unlike the influenza viruses, which must be monitored, and each year the vaccine composition changed. So there’s many different vaccine development strategies, and hopefully, one of those will lead to a vaccine, which is a – an effective vaccine that doesn’t need to be modified on a regular basis.

Emma Ross

Okay, thanks for that. There’s a question on children, and I don’t see who it’s from, but the theme is basically, “Why do some fit and healthy people get it badly, and others not? And what does the fact that children don’t appear to be seriously affected tell us about the virus?”

Professor David Heymann CBE

All these factors are still being investigated, and it’s not possible to say why some people get more infected than others. But what we do understand is that many times, the inoculating dose of virus, that is, the amount of virus that a person is infected with at the start, may have an impact on long-term outcomes. Because the more virus present in – at the start, the more virus par – the more viruses that can multiply within that person, and cause illness. So, we think that it might be dose-related, if you would, the inoculation at the start. But there’s no clear answer as to why children manifest this disease differently than do adults. But we know that there are differences in manifestation of infection. Hopefully, it will soon be understood, but there are healthy young people who have become quite seriously ill and have been hospitalised with oxygen support. What will be important is to see if, indeed, they did have some underlying health issue, which has caused that to be a more serious infection in them. But those studies are ongoing, and no-one can make definitive answers about what’s called the natural history of infection: what happens in different ages, at the time from infection, all the way on to the virus disappearing from that human.

Emma Ross

Another – the second-most upvoted, so I guess people are joining in wanting to have this answered, is “How exactly did this start?” And that’s basically from Peter Shellinck.

Professor David Heymann CBE

No-one can tell for sure. There are several hypotheses. But what’s clear is that this virus is very closely related to a virus in bats, and the theory and the hypothesis is that this – that bats somehow either infected humans directly or humans indirectly, through wild animals or other animals sold in live animal markets. And that somehow one or two people initially became infected, created chains of transmission that led then, somehow, to a major event, when many people were infected in the city of Wuhan and began individual chains of transmission that led into their families and into the community.

It’s clear that this virus is different than the SARS coronavirus. The SARS coronavirus is found deep in the lungs of humans, that’s where it reproduces. Whereas, this virus is found in the upper respiratory tract, where it reproduces and so clearly, this is more transmissible than the SARS coronavirus, which was transmissible by droplets, but mainly through medical procedures at the start, and then through heavy coughs in the community and families, and community in general. So there are differences in this virus, but it’s thought that it came, as do most other emerging infections, from the animal community, which then – the virus or the organism breached the normal species barrier between those animals and humans and infected humans.

We could envision that possibly someone bought a live animal that was infected, butchered it in the household, and became infected from the blood of that person, or their – the secretions that were coming from other parts of that animal’s body.

Emma Ross

And a follow-on question of that, and I know I asked you this last time, but it’s coming up again, of whether this outbreak will act as a wake-up call to the manner in which live poultry markets are run in some countries. And what will it take, or what is realistic for us to intervene in this species jump, species barrier jump?

Professor David Heymann CBE

Well, you know, what’s unfortunate is that there was lots of research that began during the SARS outbreak, including research in markets in China, and they actually did find that market handlers had quite a high level of coronavirus infection. Not necessarily SARS infection, but coronavirus. Unfortunately, those studies could never be completed because after the outbreak, the funding dried up. Those studies should have continued to determine whether market live animal handlers had greater coronavirus levels than others in the population. And if so, there could have been measures taken, such as domesticating wild animals to raise them for use, for human use, and processing them before they land in markets. A whole series of events that could have occurred, unfortunately, they didn’t occur, and as a result, we have another very similar incident that occurred 20 years later. So, we don’t learn from our past lessons. Hopefully, from this outbreak, we will learn that it’s important to continue to fund research after outbreaks are over, to be able to prevent these outbreaks at the source, should that be possible.

Emma Ross

Okay. Thank you. I think we’re running out of time now and we’ve got one minute, so I’ll just squeeze in, if you could answer quickly, David, on another upvoted question, even though we’ve kind of covered some ground of this, and that is your view of the seasonality factor. I guess there’s a lot of concern of whether we could hope that as the seasons change, that might lessen the burden, and that’s from James Ford.

Professor David Heymann CBE

Thanks. Respiratory viruses that cause influenza and the common cold decrease their transmission in the summer months, because people seem to get outdoors more. They’re not isolated in small areas where they’re heated and trying to keep warm, so people do leave enclosed surfaces – spaces and go outside in the summer months. And respiratory infections that we know at present do decrease in transmission during that period of time. It’s not yet clear whether the coronavirus that causes COVID-19 will do the same.

Emma Ross

Thank you, and that’s – I’m afraid that’s all the time we have for questions, but we are keeping a record of all your questions. There are loads of them, and we will bear them in mind for next time and, obviously, the questions will evolve, as this outbreak evolves and unfolds over the next weeks. So I hope you’ll be able to join us next week, where we will be meeting with David again, hopefully, the same time next week. Thanks very much, everybody.

Professor David Heymann CBE

Thank you, Emma.