Webinar: Weekly COVID-19 Pandemic Briefing

Emma Ross

Good morning and thank you for joining us again for this week’s Chatham House COVID-19 briefing with Distinguished Fellow, David Heymann. Today we’re doing to devote the whole session to your questions, so this is an opportunity for us to catch up with you on the considerable range of questions still lingering on the science and the epidemiology of this pandemic.

Before we launch in, I’ll just cover the housekeeping stuff. The briefing is on the record, so tweeting and other social media activity is no problem. A bit of guidance on asking questions, if I may. We’ve had more than 20 questions submitted in advance, which is great, and we encourage you to submit more through the ‘Q&A’ function during this session. If you did send in a question in advance, if you put it in the ‘Q&A’ function on Zoom as well and it gets upvoted, it’s more likely to be selected, so please do that. Also, the questions that were rather long and with a lengthy statement or compound, I’ve simplified them, so please don’t be shocked if I don’t read out the whole piece submitted in the question form. Where there were multiple questions submitted by the same person, I’m picking amongst them, so that we can get through more people’s questions. So, if you’re planning to ask multiple questions and one is more important to you than any of the others, it’s better that you pick the one that you care about most, rather than leaving it to me. And please remember that David is a Scientist and an Epidemiologist, so if your questions can be in that area, they’re more – also more likely to be selected. So, thank you again for joining us, and thank you, David, for joining us again.

Professor David Heymann CBE

Thanks, Emma.

Emma Ross

I’m going to launch straight into the questions, as promised, so this one is from Susanna Coll, and “What should I make of a negative antibody test result? In March, I was moderately ill, and my Doctor is pretty sure I’ve had the virus, given that I had the classic symptoms and I still have not regained my sense of taste or smell. I had an NHS-provided antibody test last week and the result came back negative. Does this mean that the test failed to pick up my infection, that I was infected, but I didn’t have any antibody response, or that the antibodies have died out by the time I took the test? Others I know have had a positive swab test then a negative antibody test, what does this mean and what should I do?’

Professor David Heymann CBE

Well, thanks, that’s a great question and it’s one that’s plaguing everybody today because people who are PCR-positive, who have definitely had infection, many times don’t give out antibody, which can be detected by the existing test today. So, what’s maybe happened is, that the test was not sensitive enough to pick up the antibody that was caused by this infection. We know though, that there are various ways that this virus acts within the human body, and we know, for example, that it doesn’t, in all cases, produce antibody that can be detected, especially in those that have less severe disease. But in this case, you had quite a severe infection, if you did have a loss of smell and taste, and so, it’s likely that you have antibody, but they just can’t be detected at present. So, that’s what the laboratories around the world are working on, trying to develop a test, which is much more sensitive, that can pick up the antibody in people who’ve been infected.

We also don’t understand what those antibodies mean, so we can’t at this point say that if you have antibody, you’re protected, because we don’t know if these antibodies protect, and if they protect, for how long. That will all become clear, as studies of the vaccine continue, and the studies in animals also continue. So a good question, sorry I can’t give you the final answer, but I think that you were likely infected, as you say, and that it’s just that the test is not sensitive enough to pick up the antibody that was produced.

Emma Ross

Just as a little follow-up to that, are there variations in the different antibody tests as to how sensitive they are, or are they all missing infections?

Professor David Heymann CBE

There are great variations in the antibody test, and the one that’s the gold standard, that is the most reliable, is one that’s called a neutralising test, and that’s a test, which takes the blood from survivors, looks for antibody in that test, in that blood, and then submits the virus, the living virus, to that antibody to see if the virus can be neutralised. It must be done in a maximum-security laboratory. So that’s the gold standard, other tests that are available are available on the market, and they’ve been regulated and approved by certain regulatory agencies, but they are still in the process of being validated to see which ones of those are the most sensitive and the most specific. We understand that most of them are not sensitive enough to pick up antibody in all persons.

Emma Ross

And is anyone using these neutralising tests, so, surely somebody must have seen whether those antibodies are protective, or is this just a theoretical?

Professor David Heymann CBE

Yes, these tests are being done by Public Health England at Porton where they have a maximum-security laboratory, and they’ve been used to do serological surveys, in various areas around the country, to determine the level of antibody. And those are the most reliable studies, and from those studies, it looks like up to maybe 7 to 10% of people might have had infection over the past six months. So, it’s not a virus that has caused a lot of infection, it’s caused a certain number, and these are detected probably by this neutralising antibody test.

Emma Ross

Okay, thank you for that answer. This is a question from Professor Olugbenga Ebenezer Olatunji. “What are your observations on the responses to and handling of the pandemic by African governments and societies?”

Professor David Heymann CBE

You know, Africa’s a real difficult epidemiology to understand at present. I’ve spoken, just recently, with John Nkengasong, who’s the Director of the Africa CDC, and also, with Chikwe, who’s the Director of the Nigeria CDC. And both of them are not yet able to discern an increased clustering of deaths that might be due to COVID, which is the way it was identified in many industrialised countries. So there are people looking to see what’s going on in Africa in most countries, and there are several hypotheses as to why the outbreak hasn’t increased so dramatically as it has, for example, in Latin America, and has it had done in Europe.

What the hypotheses are, are number one, perhaps because the population is younger, it’s a less serious illness and it’s just not being detected by the surveillance systems in the countries, and it’s not causing deaths because of the younger age. As you’ll know, the median age in sub-Saharan Africa is 19 years of age, which is quite young.

Another hypothesis is that perhaps the elderly are more shielded in communities than in the major metropolitan areas where the virus first has landed. And so maybe it just hasn’t reached those populations that are greatly vulnerable to infection and to serious illness, and it may reach them eventually.

And another hypothesis is that there may be other coronaviruses in sub-Saharan Africa that cause infections, which cause immunity, which is cross-immune to this new virus, so that that immunity also causes immunity to the new virus.

These are only hypotheses; nobody understands yet what really is going on with the epidemiology of COVID-19 in sub-Saharan Africa. But you can be sure that the Africa CDC, the Nigeria CDC, South Africa and many other countries are paying a lot of attention to this and trying to understand what’s going on. South Africa, it appears, has more of a European-type entrance of the virus into the country, and it has expanded, throughout the country, more greatly than it appears to have done in other sub-Saharan African countries.

Emma Ross

There’s a related question that’s very similar, but there’s a little bit of difference, so I was going to tack that on, from Edson Vileti. “Is the virus behaving any differently in Africa than in Europe?”

Professor David Heymann CBE

Well, that’s a good question and some people feel that it might be, but if you look at the genetic sequence of the virus in sub-Saharan Africa, the majority of viruses appear to have come from Europe into sub-Saharan Africa. Very few appear to have come in from China. And so those viruses that are in Europe are quite virulent and they haven’t genetically modified in any way, they haven’t mutated in any way that would make one think that they could possibly be causing less serious infection. But again, laboratory analysis, without understanding what’s going on in people, is not really the final answer, and so there has to be good observation correlating what’s happening in the laboratory with what’s happening in people.

Emma Ross

This is the most upvoted question from Sarah Boseley at The Guardian. “Do you think there will be a second wave in the UK and if so, how soon?”

Professor David Heymann CBE

Well, a second wave is not inevitable if countries such as the UK begin the contact tracing, which is necessary to, number one, detect patients, and number two, to evaluate their context. In other words, there need to be systems that detect cases wherever they occur, they need to then be rapidly diagnosed, and that means within hours rather than in days, and then, contacts of those patients need to be identified and they need to be asked to self-quarantine for two weeks. If they become sick during that period then they should be tested, and they should be isolated in a health facility or away from others, if they are absolutely shown to be infected. That’s one way that countries can be sure that they will be able to interrupt transmission chains that might go into communities from contacts.

Another way is to closely monitor different sectors in the country, and if there’s increased transmission in one area, in one geographic area or in one sector, then there may be a need to lockdown this sector in that area, such as is done in Asia, using what they call ‘circuit breakers’. For example, nightclubs in South Korea were found to be at great risk to transmission. They were shutdown for a time then they were opened again, and they’ve been left open because the risk of transmission has decreased. Schools in Singapore the same way, they were left open, transmission was seen to be occurring, they were closed down, now they’re open again, and transmission seem to have modified. So, it just depends on what kind of system is set up in the United Kingdom, as we move forward. Shielding the elderly, vital. Shielding those with co-morbidities, vital. Detection systems for cases, vital. And then contact tracing to make sure that transmission into the communities is interrupted. In addition to monitoring what’s going on in various sectors, to determine if there need to be temporary ‘circuit breakers’ or lockdowns.

Emma Ross

Can you elaborate a bit about – some distinctions have been made by other experts, including at WHO, between a second wave and a second peak within the first wave, or just a resurgence after easing of lockdown restrictions. Is there really a difference? Is a second wave something more natural that you can, you know, be prepared for? How is that different to a second peak within a first wave?

Professor David Heymann CBE

Well, Emma, the second waves are based on what happens in influenza and we know that in the pandemic in 1917/18 there was a second wave. We know there are second waves in influenza. This virus doesn’t transmit in exactly the same way or with the same – and it seems anyway, that influenza transmits much more easily than does this virus. And this virus still is causing outbreaks that are discrete, discrete and can be contained with virus-suppression. So, what I’d like to talk about is not a second or a third wave, but viral suppression. And if you can keep virus suppressed, as was done during the forced social and physical distancing during the lockdowns, if you can keep the virus suppressed, then there’s no need to have a second wave. But then, all those things that Sarah had asked about need to be in place, in order that there is continued suppression, and then a second increase in cases will not occur, it appears. But if countries can’t keep that virus suppressed, then there will be what some countries will call a second wave, what others will call a resurgence of the virus. But the virus will remain with us, it seems, at least for a time, and the objective is to keep it suppressed, as it’s being done now, by this forced lockdown.

Emma Ross

Another upvoted question from Eleanor Bennett. What is your view on the longer-term health effects of contracting the virus, notably the lung damage? And what this might mean for national health systems in the future?”

Professor David Heymann CBE

Well, we know that in a certain number of people who had SARS coronavirus infections back in 2003, there were severe residual – there was severe lung damage with what’s called fibrosis in the lungs. And those people have – many of them have not been able to regain their full respiratory capacity, and their capacity to exchange oxygen with carbon dioxide in the lungs. And so, we know that some people in SARS coronavirus did have long-term effects. We don’t know yet, because we’re still early in this infection, what might happen in those survivors from this infection, but it appears that some have had continued reactions in the lungs that are continuing to keep them short of breath, and hopefully, these will resolve, but we just don’t know yet whether they will or not.

Emma Ross

Another upvoted question from Nicholas Mellor. “One of the lessons learnt from the Ebola epidemics was the importance of how the technical scientific advice was understood, interpreted by the communities and Politicians. With the benefit of hindsight, how might you reframe the original technical advice to political leaders in Europe, presumably on COVID? What’s the most important issue for them to think about going forwards?”

Professor David Heymann CBE

Well, you know, what’s happened in this outbreak, in many countries around the world, is that the public health community and the political community have not been able to communicate clearly amongst themselves, or been able to deliver common messages in many cases. That’s because this is a very serious infection and because it causes mortality in a certain percentage of people, and what happened was, many political leaders began to implement their influenza pandemic plans, which were designed for influenza and not for a coronavirus. And so, it’s been very difficult for some of them to now reneg and go back into dealing with the coronavirus, in maybe different ways than they deal with influenza.

For example, in the UK, it was decided that this virus should – was being suppressed at the start by contact tracing and by outbreak containment activities. But then, when there was an increase in deaths occurring in Italy and hospital saturation in Italy, many countries, including the UK, abandoned the contact tracing and put their efforts into testing and making sure that people who were sick were admitted to hospitals. There’s no right or wrong in this, it’s just a choice that countries have made. Hopefully, now political leaders will begin to be able to work with their public health institutes in countries in a better way, such as they have in Germany, I might add, throughout this outbreak, in order that they can have a more comprehensive response to the outbreaks that are occurring. At the same time, understanding that communities are very important, because in contact tracing and testing of patients, trust is required. And trust is most easily established at the community level where contract tracers are actually known to communities, or to the local area, and can then be more effective in gaining the confidence of people who they’re trying to discuss with, and understand who might have been in contact. So it requires local action, as has been shown, Nicholas, in the Ebola outbreaks, and it occurs – it requires that in all diseases, whether it’s a sexually-transmitted infection that requires contact tracing, or tuberculosis that also has contact tracing.

Emma Ross

Another upvoted question from Frances Ogurina. “What is your take on the recent suggestion by WHO that asymptomatic COVID-19 patients are less likely to transmit the infection? Can the risk of transmission in this setting be quantified?”

Professor David Heymann CBE

There are three types of transmission, or three types of infection I might say, and transmission is suspected to be occurring from all three. The first type is asymptomatic transmission. That means someone with infection does not develop symptoms at any time. We don’t understand yet if there is transmission, and how much transmission is occurring from those people. From studies in China we believe that some can transmit to family members, for example, because in family clusters of infection, there have been asymptomatic people who seem to have infected other family members. But we don’t yet have a figure on that, the figures are coming from the modellers who make estimates based on the best possible information that they have, and some of the modellers have suggested that up to 50% of transmission comes from people who remain asymptomatic. This has not been validated by evidence, and most experts feel that it’s much lower than that.

Then there’s pre-symptomatic transmission, which occurs one or two days before people become sick with symptoms of COVID. This has been shown to occur, and there’s evidence for that from Singapore, where 6% of their adult cases appear to have been infected from others who developed symptoms shortly after the exposure. So, 6% of those people were infected by people who had pre-symptomatic transmission and pre-symptomatic transmission is understood, it occurs for measles, it occurs for many other infections, so it’s logical that it occurs for this. And then the most important transmission, as far as people believe, is those people who are sick, who have high titres of virus in their blood that are making them sick, and then during the first few days, probably up to seven days during the time when they’re sick, are able to transmit infection. And that’s what’s very dangerous for health workers who don’t have protective equipment.

So, three types of transmission. Two are quite well understood, pre-symptomatic and symptomatic transmission. Asymptomatic transmission thought to occur, but not yet quantified.

Emma Ross

Thank you. Very clear on that one. Another upvoted question from Benjamin Stokes. “How much sense does it make to focus the various restrictions to limit COVID on protecting those we know are vulnerable to it, knowing that for most people, this is not a serious illness, but for some it is very serious? Would be grateful for David’s reaction to that, and whether generalised restrictions for the whole population still make sense, with their aim of protecting the most vulnerable in mind.”

Professor David Heymann CBE

Yeah, it’s very important that the vulnerable be shielded, and they be shielded – and they can be shielded in many ways. And when I say, ‘the vulnerable’, it’s those over 75, those with co-morbidities especially, and also, people who have co-morbidities who are younger. And I think Gibraltar has shown a quite interesting way of shielding their elderly, because they’re asking the elderly to physically distance, when possible, when they’re at some or when they’re with their colleagues. But there’s also what they call the ‘Golden Hour’ every day, where the elderly go into the parks, go into supermarkets and other places, and others in the population have agreed to stay away from those places during that period of time. And this comes to the point that the most important underlying factor in making sure that countries can keep virus suppressed, is understanding by individuals how they can protect themselves and how they can protect others, and then doing it. By physically distancing, by making sure that hands are washed, and by making sure that if you are sick or if you’re dealing with people, or you can’t physically distance, or – such as a carer, or in a closed area such as a underground car, then you should be wearing a mask because that mask protect others, in case you’re infected and transmitting the infection. But everyone must wear a mask in that situation underground.

Emma Ross

Here’s one from one of your former students from Guinea, Aya Konde. “How badly do you think the outbreak, the pandemic, could delay progress made towards the eradication of vaccine-preventable diseases such as polio, especially in countries such as the Democratic Republic of the Congo?”

Professor David Heymann CBE

Well thanks, Aya, for that question and it’s a real, real issue right now, that countries must get back to their eradication activities for polio and their elimination activities for measles, and a whole series of things going on in public health systems to prevent children. Yesterday, in fact, I chaired a WHO meeting, an advisory body meeting, and we had a report from the immunisation programmes at WHO, that has shown that vaccination coverage of young children for measles vaccine, has decreased in all countries, including the DRC. Fortunately, we’ve not yet seen major measles outbreaks, as we did see last year in these countries when they stopped vaccinating. And hopefully, activities can now begin again, once the lockdown is over, so that the immunisation programmes can reach children and save lives. Because for those of you who don’t come from Africa or developing countries, measles is a very serious killer of children. It kills many, many children who are just on the border of being malnourished, or who have deficiencies of vitamin A, or other diseases, and so they are very susceptible to measles and death. So, measles vaccine prevents death in children in sub-Saharan Africa, and hopefully, it will continue to be strengthened after the lockdown occurs. So, a good question, hopefully, this lockdown has not set back efforts to eradicate polio or to eliminate measles.

Emma Ross

A question from Prashant Rao from The Atlantic. “Over these past six months or so, what big picture lessons have you learnt, David, about scientific progress, collaboration, or anything really? Has anything over the past few months changed your views on anything from a broader perspective?”

Professor David Heymann CBE

You know, I would just say that despite all the political tensions going on in the world today, there’s been a free sharing of information about this virus. That began with China in January, maybe not as rapidly as many would have appreciated, but it did begin and it’s continued from China, information continues to flow from the US, and from other countries to WHO. WHO is able to analyse this information, look for the evidence, and then present this information to its advisory bodies, who help them make recommendations. In addition, the medical journals have agreed not only to rapidly peer review articles, but also, to put them on the web in front of the paywall, so that everyone has access to this information. The way that we’ve learned about this virus is quite impressive and rapid. We learned, within the first months, how this virus transmits from person-to-person, we learned its genetic characteristics, we learned its transmissibility, and we learned a lot about the spectrum of disease that occurs when one’s infected.

There’s still a lot to learn, and I can safely say, because I know being with WHO and their advisory groups, that they are still receiving the information they request. In fact, last Tuesday the WHO advisory group that I chair, received a full report from the Chinese CDC, from the Epidemiologists there who reported exactly what had happened in the market as far as they understood it, in Beijing, what they knew about the infection, what they knew about people infected, and how they were proceeding to lockdown certain sectors in the area of that market. So, within a period of 15 minutes, we understood everything that was going on through the China CDC’s report to the WHO advisory committee, where WHO experts were also sitting. So there’s been free flow of information, despite the fact that there are geopolitical tensions, and this is what happened in the SARS outbreak, it’s what happened in the Zika outbreak, and we hope that it will continue to happen in this outbreak.

So again, a short answer, despite the geopolitical tensions, WHO’s technical arm continues to function fully.

Emma Ross

But has anything changed your views on anything, from a broader perspective, this experience, having been in a front-row seat for this, has it changed the way you look at outbreak control, in your vast experience, have you learned anything new?

Professor David Heymann CBE

Well, what I’ve learned from this is that political leaders and public health leaders just are having difficulty communicating. And that’s really difficult because there hasn’t been an epidemiological approach to containing this virus, in many countries, because of that. So that’s one thing I’ve learned in this outbreak, when there’s an outbreak, which is causing serious mortality, political leaders sometimes don’t pay full attention to what the technical leaders are recommending, and this happened in many different instances.

And the second thing that was very interesting to me is, how political leaders followed the example of China, and just locked down their sectors, in order to try to suppress virus transmission, doing that procedure, which had been done by China previously, and not paying attention to what was being done in other parts of the world where there were, in many ways, a more tailored epidemiological approaches to the containment.

I also remind people that in 2003, China did not report, for several months, what was going on in China. Everyone knew that there was an outbreak going on in China because one of the Medical Doctors, who had been treating patients in China, came into Hong Kong, and from his hotel room, was able to spread the virus to people on his hotel floor, who returned to several different countries and continents, and started the global outbreak. That was only changed when the Director General required – accused publicly, WHO, of not reporting and putting the rest of the world at risk, and the next day the Vice Premier from China was on a plane to Geneva, apologised to the Director General, and began to report freely and the country stopped the outbreak. This did not happen this time. China did report freely when the government, the central government, says they became aware of the outbreak and were able to understand what was going on. They immediately provided a report to WHO, at the end of December, in 2019. The information then flowed regularly, as WHO asked for more information it became available, so that by the 30th January, enough information was obtained, so that the Emergency Committee felt they could recommend that this was a public health emergency of international concern.

Emma Ross

Can I just have a little follow-up question to that. Your comment about the sub-optimal understanding between Scientists and Politicians, what affect do you think that’s had on pandemic control?

Professor David Heymann CBE

Well, I think in some countries the political leaders have not been able to suppress the technical leaders, whereas, in other countries, there has been equal representation from all, and in some countries, there’s been an epidemiological or a public health face, whereas in other countries, it’s been a political face to this outbreak. That will change over time as political leaders begin to understand that public health leaders can contribute, and I think they’ll be more comfortable in many countries in ceding this leadership to the public health leaders, who are in fact those people who are best equipped to make recommendations moving forward.

You know, everybody may have made mistakes, every country may have made mistakes. It’s building a ship while you’re sailing it, and whatever has been tried has been tried with good intentions.

Emma Ross

Got a couple of questions on vaccines here. One from Charles Clift, I’ll ask you both of them together. “What do you think are the chances of finding an effective vaccine, and how can we ensure equitable access globally?” And Michelle Reemers, “Can you comment on the main vaccine prospects as they stand today, likelihood of success, either in fighting the virus or immunity, and timelines as you see them?”

Professor David Heymann CBE

Well, there’s – and thanks, Emma, there’s unprecedented work on vaccines. There are four different types of vaccines that are being attempted to be developed, and these four different types are – and some of them are quite novel and new, and there have never been vaccines developed with these techniques before. One of them is using the RNA mol and the other is using what’s called virus-like particles, which are particles that imitate the virus and can cause, hopefully, an immune response.

These vaccines are at various stages of development, and some are in clinical trials in China, in Europe and in North America, or at least from developers in those countries. We’re not yet seeing outcomes from those, vaccine development requires quite a bit of co-operation from countries, and it requires high levels of transmission of the virus. What we’re seeing is that countries that have begun human studies of these vaccines are those countries where transmission is lower, so many of them are trying to begin to work in Brazil and other countries where transmission right now is high, as well as in countries in Europe and North America, to see if they can develop the effectiveness of these vaccines by comparing a group of people who are vaccinated to a group of people who are not vaccinated, while making sure that of all these people are following the known ways of preventing infection, because if that vaccine should not be infected, it would not be ethical to not recommend to these people that they also be using the techniques that they know can prevent infection. So that’s one type of studies that are going on.

There are discussions now about whether or not it would be valid or ethically acceptable to give a challenge dose of virus to people who are vaccinated, and to people who are not vaccinated, to see if the vaccine protects those people who are vaccinated. This has been done in diseases such as malaria, where there is a treatment, should people become sick. But in this illness there’s no cure yet for the infection and so, it’s a very difficult ethical decision, to decide whether or not to infect young people who might get serious illness, and could go on to die if they’re not protected. At the same time, it’s not clear whether by vaccinating younger people, the elderly people will respond the same way to the vaccine. So, there are a whole series of questions about when vaccine trials can be completed, and then, those vaccine trials will show whether or not the vaccine has been effective.

Emma Ross

Do you have an opinion on whether you think – what our chances are of finding an effective vaccine in time to influence this pandemic?

Professor David Heymann CBE

Yeah, I can’t give an answer to that, the only answer I can say is that we need to use the tools we have today, and that means getting better use out of our diagnostic tests, and our contact tracing and patient identification, in order that we can stop and suppress how best we can now. It might be that there is a therapeutic agent available sooner than a vaccine, but hopefully, the vaccine will be available and then it requires, as was said, equal distribution in the world to those populations at risk. Well, European Union and Bill & Melinda Gates Foundation and others, have developed what’s called the ACT Accelerator. The accelerator to increase research in vaccines, in diagnostic tests, and in therapeutics, and at the same time, to make sure that there’s more equitable distribution of those within countries. There are diagnostic tests…

Emma Ross

Yes, but how?

Professor David Heymann CBE

Sorry?

Emma Ross

Yes, but how are they going to…?

Professor David Heymann CBE

Yeah, I was just going to say that.

Emma Ross

Okay.

Professor David Heymann CBE

There is an effort – this is a $9.8 billion activity, the ACT Accelerator, and hopefully, diagnostic tests, which are now available, can be made available, and there’s an organisation called FIND Diagnostics, which has been charged by the ACT Accelerator with distributing diagnostic tests that are purchased by FIND to countries that need them, and also, making sure that the training required is there in those countries to make sure that those tests are adequately used. So, diagnostics will be the first thing, the first test, as to whether or not this ACT Accelerator can guarantee equitable distribution of an intervention that’s available for controlling this outbreak.

Emma Ross

Okay, great. There are a couple of follow-up questions from others, a Dr Audrey Wells. “Should any vaccine be tested in a country where the infection rate is high, rather than in the UK where it’s much lower and the effectiveness more difficult to test?” And then Dina Mufti, “Considering the process for developing the vaccine has been accelerated, is there an increased risk of negative side effects?”

Professor David Heymann CBE

Yeah, well, the first one, yes, and countries – companies are beginning to look into Brazil and other countries that have high levels of transmission, so that they can do more rapid study of their vaccines there, ad there have been trials set up in Brazil. China is also working on trials, and I think they’ll be able assess their – now, in the Beijing outbreak as well, moving into that area to see if those vaccines are effective.

Looking – what was the other question Emma? You’re muted. You’re muted, Emma.

Emma Ross

And what was about the risk of side effects from…

Professor David Heymann CBE

Yeah.

Emma Ross

…speed, accelerating development.

Professor David Heymann CBE

Yeah. Well, you know, what’s happened is that the regulatory agencies and the vaccine development groups are working very closely together from the start and no-one will compromise on safety, either the vaccine developers or the regulatory agencies. So, that’s the first studies that have been done, and these vaccines have been shown – the vaccines that are in human trial now are being shown to be safe in humans, and they’re being shown to develop some type of an immune response. So that’s the first step that has to be done, and no-one can compromise on safety.

Many vaccines are still at the animal phase, being studied in animals for safety and effectiveness, and then they’ll move into human effectiveness studies. Regulatory agencies pay close attention to this, they then will also take the information that comes in from the trials to see whether or not there has been effectiveness of the vaccine. And finally, regulatory agencies will consider whether or not they should give a provisional licence to these vaccines, so that they can be used provisionally and in countries where there is a good surveillance system to detect if there are any reactions to the vaccine, when it’s used in large numbers of people, and to determine whether it’s effective in those populations at greatest risk. So, all of these things are being considered by regulatory agencies, I think I can guarantee that in European and North American countries, safety will not be compromised. I don’t know exactly what’s going on in China, but in order to have these vaccines registered and licensed in industrialised countries, they must be also paying attention to the safety, and I’m sure they probably will be doing that. But I can’t say that for certain.

Emma Ross

Thank you. That’s it for vaccines for the moment. Another upvoted question from Neil McLeod. “What do we know about transmission with children at the moment, can they be vectors of the virus?”

Professor David Heymann CBE

Yeah, we don’t know really a lot about children unfortunately yet. The Chinese have found that children do not get serious illness, in the majority of cases, but some do get a generalised inflammatory reaction, and this is being followed, as you know, in Europe and in North America in the children who have had this, and there have been very few who have had this generalised inflammatory reaction. In general, it’s thought that children, if they get infected, don’t have serious illness. It’s not yet clear if they are infected, how they transmit, if they do, to others in the household. But some of the evidence from China suggests that some children have transmitted to adults in the same households. So we – the children is one of the major areas of study now, and in the UK there’s a – UKRI has set up a series of rapid application procedures for research to look at issues such as this, and those research activities are being heavily funded by the UK Government, to make sure that there’s complete understanding of what’s going on in children.

Emma Ross

One on mutations from Lavinia Harvard, it’s an upvoted question. “Has the virus mutated, if so how many variants are known?”

Professor David Heymann CBE

Yes, the virus is regularly mutated – mutating, but not as rapidly as do other RNA viruses such as influenza. So, the mutations are being tracked. I can’t give an answer as to how many different variants there are, but this is being tracked by a website called GISAID, G-I-S-A-I-D, and this website is accessible by public health and other experts. What is clear is that the mutations that are occurring have not yet been correlated with either a change in the way the virus transmits, or a change in the virulence of the infection that occurs, once a virus infects humans. In other words, it seems to be remaining virulent, especially in those populations at risk, and it appears to be transmitting in the same way that it has before. So, there always needs to be a correlation between what’s happening in humans, and what the sequence is, and that’s why laboratory people always must work very closely with Clinicians and the Epidemiologists in order understand fully what’s going on.

Emma?

Emma Ross

Thanks for that. Here’s one from Margaret Rainford, “With the number of COVID-related deaths in the UK continuing to reduce, could the virus be attenuating naturally?”

Professor David Heymann CBE

Well, that’s a question that nobody can answer at this point in time. We do know that other viruses attenuate. We know the Zika virus came and left. We don’t know where it is. We just don’t know the destiny of this virus and so whether or not it attenuates or not is not yet clear, but I expect that the decrease in the UK, as decreases in other parts of the world, is due to the suppression activities, which have been so intense. And now the challenge will be to keep the virus suppressed by good epidemiological principle, and application of that epidemiological principle into practice.

Emma Ross

Okay. Thanks. Here’s one on dexamethasone from Louise Hart, an upvoted question. “Other than dexamethasone, are there trials of other potential treatments that are close to releasing results or showing initially encouraging findings?”

Professor David Heymann CBE

There are several different drugs that have been repurposed, in other words by repurposing they don’t need to go through safety study, they can just go into humans to see if they’re effective, in this case in treating people with COVID-19. Some drugs have been removed because the Data Safety Monitoring Board, which is a group that unblinds all the data, that looks at all the data periodically during the study, has determined that they are not effective and therefore, they should be removed, they’re not having any impact on the disease. Other medications and therapeutics that are under trial and reviewed by the Data Safety Monitoring Board, the results are not released because those studies must remain blinded and must remain to completion. So, I don’t have access to that information, but I’m sure there is information available on some of the drugs, which are being used now, as well as on some of the antibody preparations that are being used. Because antibody has been effective in treating people who have rabies, in people who have hepatitis B, a whole series of other viral infections, including the haemorrhagic fevers and Ebola, and it may be that antibody, even though we don’t understand how it works, might be effective in a concentrated dose, in either preventing serious illness, or in some instances, preventing people from getting infected. We just don’t understand enough about it.

So, the short answer is that we don’t – I don’t have any information on other drugs that might be shown to be effective. The only two I know about are – three, are Zithromycin, hydroxychloroquine, which have been shown to not have effect, and remdesivir, which has been shown to shorten the time to recovery in those people who are seriously ill.

Emma Ross

Thank you, and we’ve got time just for one more question, this is from John Spowort. “What are your thoughts on the possibility that China’s intensive wildlife trade industries provided the optimal conditions for zoonotic emergence, and is very likely the cause of this one?” The questioner believes there’s a danger and potentially more serious than crossovers from domesticated animal raising and believes the distinction is a bit neglected. So, do you agree with that, and in a segue way, would a ban on the commercial exploitation of wildlife avert pandemics?

Professor David Heymann CBE

Well, first of all, bans are very dangerous to do because if you don’t have the force to really make sure that those bans are occurring, what happens is they drive the trade underground. And we know this happened after the SARS outbreak in parts of China, where it was made illegal to sell wild animals in markets, and therefore, the trade went underground. That’s been shown to have occurred, and it occurs in many other places. China’s not the only place where there are live animal markets, and it’s not the only place where infections are transferred from animals to humans. We know this occurs in Ebola in Africa from live animal markets, and those animals are bought and slaughtered, the blood infects humans who are either slaughtering the animal to sell it, or taking the animal home and slaughtering it at home, and we know that the 2003 SARS outbreak occurred from wild animals, and we believe that this outbreak did as well.

Unfortunately, after the SARS outbreak in China in 2003, there were studies that were begun in markets, which showed that handlers of wild animals in markets had a 13% prevalence of antibody to SARS coronavirus, whereas, only 1 or 3 – 1 to 3% of the population in communities had that antibody. These are studies that should have been continued, but after all outbreaks, it’s a real difficulty to keep the funding flowing for research, because that funding is diverted to other health priorities. And in China and elsewhere, there hasn’t been thorough study of whether or not these animals, in some way, are transmitting, and whether or not they can be domesticated, in such a way that they don’t transmit, or whether market trade should be banished, but if it’s banned, it also needs to be controlled and there need to be regular inspections to be sure that the market hasn’t been driven underground where it won’t be identifiable.

Emma Ross

Thank you, David. I think we’ve run out of time now to keep it to the 48 minutes, sorry. Three minutes over. But thank you for that, and I’m sorry to everyone else for the outstanding questions, I tried to go as quickly as possible to zip through them, while allowing David to give comprehensive answers. But thank you all for joining us and thank you, David, again.