Sustaining the response: COVID-19 briefing

Emma Ross

Good afternoon and thank you for joining us for the return of the Chatham House COVID-19 webinar series, with our Distinguished Fellow, Professor David Heymann. For this run of the series, we’ll be focusing mostly on issues relevant to Sustaining the Response, and navigating our way through the next few months, and more. A year into the pandemic, we were hoping we might be able to frame this leg and series around emerging from the pandemic. But while it may look like we’re almost out of this, thanks to the rollout of vaccines, it’s not quite so simple, and there’s still a lot to deal with.

We have back with us today David Salisbury, who is an Associate Fellow at Chatham House, and one of the world’s leading experts on vaccines, from developing them, to delivering them. So, welcome, David.

Professor David Salisbury

Thank you, Emma.

Emma Ross

Just some housekeeping briefly, first. The briefing, as usual, is on the record, and, so, you can tweet using the #CHEvents. Questions can be submitted using the ‘Q&A’ function on Zoom. Upvoted questions are more likely to be selected, so please do submit questions, and any time you like during the conversation, and upvote ones you particularly like. I’m going to start today with David Heymann, to orient us on where he thinks we are with the pandemic at the moment, and to take on one of the hot topics of the day, all these new variants of the virus.

So, David Heymann, more than six months ago now you were one of the first voices to be talking about how we’re going to have to learn to live with this virus. In the last few months, that view seems to have gained a bit of traction. Can you update us on what that really means today, learning to live with the virus? Where we are now with the pandemic, in terms of our hopes of it being over? Or, even, you know, if you think it’s never really going to be such a definitive endpoint and how you think we have to be thinking at this point in the pandemic. I mean, what’s really achievable now, and why did you want this run to be framed around Sustaining the Response?

Professor David Heymann CBE

Well, thanks, Emma. I think if you speak with most Epidemiologists and most public health workers, they would say today that they believe this disease will become endemic, at least in the short-term, and most likely in the long-term. Although, again, we don’t know the final destiny, and that will depend on many, many different things. But I think the reason that we need to begin to live with this in a sustainable way is because of the great advances that have occurred in research, for new diagnostic tests, for therapeutics, and, also, for vaccines, that David will be talking about later.

So, I think we have very many tools that we can begin to live with this outbreak and this pandemic, rather, moving forward. And some of those tools will actually help our political leaders fulfil their promises of protecting lives, and decreasing the burden on hospitals, while, at the same time, permitting them, after they get more and more evidence, to maybe develop different strategies moving forward. Right now, the emphasis is on saving lives, which it should be, and on making sure that hospitals are not overburdened with COVID patients. And this will be possible moving forward by the vaccines that David will talk about later.

So, sustaining the outbreak will mean a whole series of things, and it will also mean that we have to have in our minds that we need to be constantly doing our own risk assessments, and doing what we need to do to protect others, and protect ourselves. Up until now, the government has done much of that, in many countries, by locking down areas where transmission occurs, where people aren’t physically distancing, or aren’t wearing masks. And soon, we’ll have to learn how we do this on our own, so that we don’t take infection back home to elderly people in the household, or so that we don’t continue chains of transmission into the community.

So, these are some of the things we have to worry about, and move ahead with, while our governments have to do a better job at doing outbreak investigation, stopping small outbreaks when they occur, and preventing that community transmission.

Emma Ross

I’m just wondering, David, do you think there’s an element of learning to live with this virus that societies, maybe not government, but societies will have to come to terms with what scale of illness and death they’re willing to tolerate, in order to have a more normal life? That, you know, hiding from it, or locking people away from it, I mean, how much longer can we go on with this? Especially with the new variants and, you know, talk of maybe the vaccines aren’t going to be as quick, or as effective. Is there an aspect to that, of society deciding what it can tolerate? ‘Cause there are all sorts of other diseases that cause sickness and death that we don’t go into lockdown.

Professor David Heymann CBE

Yeah, well…

Emma Ross

Is that an aspect that needs to be dealt with?

Professor David Heymann CBE

Emma, I think it’s good to put this in context, and think about the other infectious diseases that are endemic today. Most of those have come from the animal kingdom, at some point or another, including four endemic coronaviruses that cause the common cold, including tuberculosis, including HIV, which came from the animal kingdom in the 20th Century, and we’ve learnt to live with all of these infections. We’ve learned how to do our own risk assessments. We’ve got vaccines for some, we have therapeutics for others, we have diagnostic tests that can help us all do a better job of living with these infections.

It’s not that we say now we have to just do this especially with COVID, we have to continue to do it as we’ve done with other infections. There are a couple unknowns which make it very difficult for political leaders and public health leaders to make decisions as to what would be the best strategies, including the fact that we don’t completely understand long COVID, and its impact, or its occurrence, after even very minor infections. And there are some things we’re trying to learn very rapidly, along with other things trying to learn from vaccines, that will help us face the future in a more confident way.

But there will be no decision that while we will accept this amount of deaths, we will – what we will do is work together to try to deal with this infection as we deal with TB, which causes deaths regularly, and HIV, and other infectious diseases. So, it’s not a matter of this being a special disease, this is one of many that we will have to balance our living with and understand how to deal with it as we do with influenza, as we do with other infections.

Emma Ross

Okay, thanks for that. I want to get on now to the new variant. So, there’s been a lot of discussion out there already on the emergence of new variants. So, not going to go over a lot of the stuff that’s already out there. But, also, there’s a lot of talk about how there’s probably more out there as yet undetected, and that there will be even more, and the complications that might have for our journey out of the pandemic. You’re at the centre of the global level discussion of this as Chair of the Strategic and Technical Advisory Group on Infectious Hazards at WHO. I assume you’ve been talking about the variants at your meetings, no?

Professor David Heymann CBE

Actually…

Emma Ross

Can you give us an update on what the thinking is on the variants? I mean, whether there’s been anything surprising, how concerning, what should we do to mitigate or adapt, and where this whole variance thing is likely going?

Professor David Heymann CBE

Well, there’s a lot going on in the discussions about variants. In fact, WHO recently had a three-hour meeting, which had over 2,000 participants from around the world, sharing experiences and listening to presentations on variants. So, it’s really something which is being studied in great depth by WHO, and by many other groups around the world. Variants are a normal phenomenon in an RNA virus. They mutate continuously, and I think, Emma, everyone understands how a mutation occurs. It occurs because viruses, when they enter a human cell, must use the code that they have to formulate new viruses within that cell using that cell’s mechanisms to make the viruses. And in doing that, they use a code, and as they transcribe that code, many times there are mistakes that are made, and those mistakes then show up in the new viruses as mutations and, so, mutations are a common phenomenon with RNA viruses.

Influenza’s another RNA virus, polio’s another RNA virus, and they constantly mutate. Many times, they mutate in a way that they could somehow change transmissibility. Sometimes they mutate in a way that could change virulence. But usually, they just mutate in a way that makes them a new type of – shows up a new variant that many times, they don’t have any effect at all. And, so, what we’re seeing is that this virus, as all RNA viruses, is just going through a natural phenomenon of variation in variants continuously.

Some of these viruses end up with many, many different mutations on the same virus, and that’s a question as to why this occurs, and there are many hypotheses. But one of the most important hypotheses is that the viruses that accumulate, so many mutations on one virus may be doing this because they circulate for a longer period of time in one person. And in that person, as they continue to reproduce over a long period of time, they add to each mutation a new mutation as they go along, or, to the virus, a new mutation. And that occurs sometimes in people who have immunosuppression, who have been immunosuppressed from birth by some type of a congenital abnormality, or, in fact, some who may be HIV infected.

This is not new. With polio viruses, there are people who have been secreting viruses that have come from the live polio vaccine for many, many, many years, and who have accumulated certain mutations on those viruses. So, it’s not a new phenomenon, but it’s a hypothesis that this might be occurring with this virus.

Emma Ross

So, is that the leading theory of how these variants are arising, in immunocompromised patients who are having chronic infections, and that gives the virus, you know, an extended period of time to be making loads of mistakes? Is that what we’re thinking where these are coming from?

Professor David Heymann CBE

Mistakes happen in most – in many, many different people, as viruses reproduce. But if they reproduce for a long time in one person, then those mistakes accumulate in the same virus and, so, as I said earlier, variation and mutations are common. Viruses make mistakes as they reproduce. But if they have the opportunity to reproduce for a long period of time in one individual, then these mutations accumulate, and you can have a virus with up to 20 or 30 different mutations on one virus.

Emma Ross

Well, before I go to David Salisbury on linking the variants to the vaccines, and I just wanted to ask you, David Heymann, of – about whether we’re learning anything new about immunity? So, I saw a worrying report on this 45-year-old immunocompromised man in America, who kind of remained infected for 154 days, and he was infectious for five months after diagnosis and the virus was picking up whole clusters of mutations, all at once. And the virus was resistant to monoclonal antibodies he was being treated with, and, apparently, that’s not an isolated case. Is this giving us any clues as to what’s happening with immunity? Could there be lots of other people who are infectious for way longer than the two-week quarantine period?

Professor David Heymann CBE

Well, Emma, first of all, it’s important, again, to look in context and the four endemic coronaviruses that give humans the common cold have an immunity, which is short-lived. It lives maybe up to six months or longer, that immunity, and then you can be reinfected with that same virus. This, we believe, can also occur with the human coronavirus, the SARS coronavirus, too, that causes COVID. But we don’t know exactly, to what extent, it will be occurring in the future. We do know that there are reinfections of people who have been infected, who have developed strong antibody response, or immune response to the virus and then, six months later, they can be reinfected with a variant of the virus.

So, we know that occurs, and we know, from some studies in South Africa, that some of the variants that have occurred there, or the major variant that has occurred there, may not be responding to the immune response that was created by infection from a previous variant, or a previous virus. What that means is that people who were infected in the past are now being exposed to this variant, and they’re not protected against infection with this variant, to a certain extent. And, of course, people with those immunities long-term, including possibly HIV-related immunosuppression may, in fact, produce that virus for a longer period of time.

Emma Ross

Okay, thanks, that sounds worrying. David Salisbury, I want to come to you now, segueing from variants to vaccines. Can we get your take on to what extent these variants are putting a spanner in the works for the vaccines? I mean, we hear about several studies, and some sound scary, while others are reassuring. And I don’t know if I’m alone on this, but it’s hard to know what to think, really, regarding how much of a threat they really are. Is this whole subject being exaggerated, downplayed? What’s your take on how the new variants will affect vaccination programmes and our exit from the pandemic?

Professor David Salisbury

That’s a huge question, and I have to say, as an opener, I don’t know the answer to your question. I don’t think anybody knows the answer to your question. Every day, right now, we’re getting more information about vaccines. We’re hearing more results from studies. We’re hearing more vaccines are coming through the regulatory process. So, you know, that’s all very positive, and you could take one reassuring bit, and that is to say, if you’re living somewhere where you know there’s a good match between the vaccine and the currently circulating viruses, including some variants, and the UK is an example here, you can be confident that the current vaccines are giving good protection against those variants.

Then look at the situation in South Africa, where you’ve got a completely different situ – circumstance, and a much less comfortable one, where the vaccines that are currently being manufactured in huge quantities were put through clinical trials, and they appeared to be giving day – evidence for efficacy, and then we got the variants. And the variants that are now emerging appear to be escaping from the vaccines that were originally being tested. So, their situation is much less comfortable. Then, there’s the other bit that I think we have to factor into this, that the vaccines that are currently coming through are not all the same. And because they’re not all the same, we shouldn’t be surprised at getting different results on immune responses, different immunogenicity results, and we shouldn’t be surprised at getting different efficacy results.

We have got vaccines that are ranging between RNA, which is entirely new. We’ve got recombinant protein vaccines with adjuvants in them, and we’ve got viral vectors, and we’re going to be having inactivated whole-virus vaccines coming as well. So, we should not be surprised at different immunogenicity, and the results do look different for the immunogenicity. We shouldn’t be surprised at different efficacy, and if we have different efficacy, we shouldn’t be entirely surprised either by having different responses to variants. And it just depends how broadly the immunity that you have from the vaccine extends to protect against the variants. So, I think that the current situation is playing out. We are learning much more about the variants. We’re learning much more about how the individual variant – vaccines protect against the variants, and all of that is going to play into the longer-term for the future.

I’m very happy to go on to extrapolate my – that view into where I think the future will be, if you want me to deal with that now, or…?

Emma Ross

No, I do. One thing that suddenly cropped up for me is, do – and as far as, you know, where you think this is going in the future, is there a possibility that we might – or I’m thinking if you’re an individual that’s ready for a vaccine, or being invited for vaccine, I can see where people might say, “I want this one, not that one,” you know, according to what’s going on with the variants. Will we be in a situation where we will get to choose the vaccine we want, or people might refuse to have vaccine A, versus – you know, look what’s happened in South Africa, with the suspension of the AstraZeneca, ‘cause they feel it won’t work against that variant. Has that ever happened with others, where there’ve been so many choices where there’s been pressure, this kind of push-pull of – or menu system? Is that in our future, or is there just not enough to go round that we’d have that luxury of shopping around like that, on an individual level?

Professor David Salisbury

I can’t think of circumstances where we’ve had, you know, a menu of different vaccines, and we choose the one for our first course, and we choose the one for our second course, and we choose the one for our dessert, based on our own interpretation of what will give us the best response. No, I don’t believe we’ve been really in that position, that I can immediately think of, before. I’m asked this question, and my answer is the same: take whichever vaccine you are being offered because the one thing that has been common, to all of the vaccine results, is that they protect against severe disease and death. And that is the consequence that we need to currently be taking as the first order of desirability. We want to be sure that the vaccines are protecting us from severe disease, hospitalisation, and death, and they all seem to be doing that.

The choices will be made very – to a very considerable extent by the contracts that governments have got in place, so that we, the population, can be protected as best possible. And those choices may be very impactful in the future, and we don’t know that yet, in terms of whether one particular vaccine protects against variants better than another one does. So, in the short-term, I think we must be grateful for any offer for a vaccine, and take that, because they protect against severe disease and death.

Now, I cannot predict, and I don’t believe anyone can predict, whether more variants will appear that have different characteristics, in terms of both transmission and consequences. We just don’t know. At the moment, the variants in the UK may be transmitting more quickly but are not giving more severity of disease. So, we may have more variants and they may become less well-protect – you know, defended for us against increasing variants. And then I think we have to look to what the future means for vaccines, because if the viruses continue to mutate, the variants are no longer being covered by the vaccine, we have to have new vaccines, and we have to, of course, then ask what about the people we’ve already vaccinated? Are we not going to have to do them again, and again, and again, each time that we change the formula of what’s in our future vaccine?

And when I…

Emma Ross

I’m sorry.

Professor David Salisbury

I’m sorry?

Emma Ross

Would we have to?

Professor David Salisbury

Yeah, I think that is a very real possibility, and when I think about that, the model comes to mind very quickly that this is just like seasonal flu, because we now vaccinate against seasonal flu, with four separate influenza viruses in our vaccine, and we don’t think twice about having four different virus strains in our seasonal flu vaccine, and we don’t think much about having the same people vaccinated every year to protect them against seasonal flu. So, in the medium and longer-term, I would be surprised if we continue to depend on a single virus, coronavirus vaccine. I think that we will be forever chasing our tails, as each variant then starts to spread, and we’re having to then think, “Oh my goodness, we’ve got to reformulate the vaccine, start all over again.”

So, my vision, as this goes further, is that we will be looking at multivalent coronavirus vaccines that will now have one, may have two, may have three, may have four different viruses. And that will depend on whether these very different vaccines can be adapted from monovalent to multivalent, and if they can be adapted to multivalent, someone will have to do the sort of forecasting that we currently do for seasonal flu, about what are we going to put in this year’s mix? And then, who are we going to vaccinate? And I think that the – again, the first order of choice there is, we vaccinate the risk groups. And the reason that we vaccinate the risk groups is that they’re the most likely to get seriously ill and die and that’s mapping very nicely onto our seasonal flu vaccine programme.

We will have some political, moral, ethical considerations about what do we do with people who are not in the risk groups? They’re much less likely to die, but they may get long COVID. But in terms of the economic impact, and in terms of the health system impact, that’s much less. So, we may be in a position where just as we do with seasonal flu in most countries in the world that have seasonal flu programmes, we vaccinate the risk groups, and we say to the others, well, it’s a pretty mild disease for most people, and we don’t have routine vaccination for the whole population every year, against whichever coronavirus is circulating. And if we do that, we protect our health services.

Emma Ross

Do you think that we would have the capacity to do – ‘cause it seems like a major push, and concentration of resources to get it done. Is this just a learning curve? But if we had to do this every year, we’re still in – doing the risk groups like, say, in this country, but if we talk about that on a global scale, if, you know, everyone needs vaccinating globally to keep, you know, the variants in check, etc., that level of intensity, that number of people vulnerable around the world, do you think we’re equipped to keep that up?

Professor David Salisbury

No, we’re not, and that takes us back to what is it that we’re trying to do? And we cannot vaccinate even high-risk populations everywhere in the world, every year. And we don’t do that for flu, and flu, of course, is not the same burden in all parts of the world. But we will have to think very carefully about what supplies of vaccine will be available long-term, ‘cause so much of the discussion, COVAX, for example, so much of the discussion is short-term. It’s about protecting people now. But the question you ask about resilience and capacity to do this over and over, not just human resource capacity to implement it, but the money to buy the vaccines year-after-year, I would be very surprised if the global enthusiasm continues to be able to support both the opportunity cost of vaccinating large numbers of people every year, and the financial cost of doing it year-after-year-after-year.

So, I think that it’s a – it’s hugely important that we have schemes like COVAX, working on behalf of countries that do not have access to what the industrialised countries are privileged to have, and get vaccine to them to protect their essential services, to protect their most vulnerable. But will we interrupt transmissions through vaccination in every country in the world, with the vaccines that we have, that are not 100% effective, where variants are coming the whole time? I think the answer is no and, therefore, we have to again be realistic about what vaccines can do on a global scale.

I think that they can do wonderful things to protect the most vulnerable. My prediction is that interrupting transmission, on a global scale, through vaccination, is going to be probably impossible, and we therefore will have to think about other steps to reduce transmission. But, along with what David was saying earlier, if this virus is something that we’re going to have to live with, I think we will have to accept that living with it is not the same as eliminating or eradicating it.

Emma Ross

Hmmm, okay, that’s pretty depressing.

Professor David Salisbury

I’m trying to be really…

Emma Ross

And David Heymann, does this mean now, does all this indicate – first of all, do you agree, or what do you think of what David Salisbury’s just said and does this all indicate that more focus maybe needs to be put on developing some therapeutics, or is the outfoxing going to be the same problem with therapeutics? Seems like therapeutics have kind of fallen into relative neglect lately, or maybe they’re just not getting the attention, but what do you make of what David Salisbury’s just said?

Professor David Heymann CBE

Well, I certainly agree…

Emma Ross

And then I’ll go…

Professor David Heymann CBE

…with David.

Emma Ross

…onto questions.

Professor David Heymann CBE

Yeah, I certainly agree with David and, you know, just to finish up with vaccines, and then move onto therapeutics, vaccines save lives and decrease the burden on the health system, as David said. And therefore, there really is a global obligation to be working together to make sure these vaccines get to places where they’re needed, and where governments are engaged in providing them to their people because if you get them to a country that doesn’t have government engagement, they won’t do any good. So, right now, these are vaccines that prevent death, save lives, and decrease the burden on the health system, and we should work together, through the COVAX facility, to get those vaccines out.

And then, as David said, if we do find that they really do prevent transmission, then there’s a whole another reason to get these vaccines out to all countries. And that might be as follows: as transmission – as the number of people that is infected increases, the transmission of those viruses to those people increases, and the numbers of viruses that are replicating in humans increase, and the possibility of making errors increases, and the possibility of variant strains increases. So, if we see that these vaccines actually prevent that, prevent infection, prevent that opportunity for variants to develop, then we have a reason, a double reason, to get these vaccines out to places where transmission is greatest. So, there are all kinds of reasons why we should get these vaccines out, but we need to make sure that there’s a more equitable distribution now, and possibly, for other reasons, in the future.

Coming to therapeutics, the research is quite healthy in developing therapeutics. It’s been going on and there’s a lot of research going on. But it’s been overshadowed by vaccine research, because vaccine research has been so successful, so rapidly, and because we all understand the power of vaccines. We also, though, do see that there are studies going on in various areas on monoclonal antibodies, as you said, Emma, and in other therapies, in antiviral drugs. And there are also new diagnostic tests, which open up new strategies for diagnosis. And these are all very healthy and moving forward, and we just hope that they have to keep moving forward together because vaccines will only be a part of the solution, moving forward. Vaccines will be a failsafe, and they will save lives, but there then can be therapeutics that can also be used, and good diagnostic tests, which helps people understand when they’re infected, and how they can behave not to infect others. So, yes, therapeutics and diagnostic tests will play a major role moving forward, and research must continue in those areas as well.

Emma Ross

Okay, and we’ve got to get more accurate diagnostic tests, right? That are more robust.

Professor David Heymann CBE

Absolutely, and that’s – that work is going on.

Emma Ross

Okay, thanks. I’m going to move to questions now. The most upvoted question, by far, is from Charles Clift. “Should we, in the UK, stop vaccinating our own people once we have vaccinated everyone over 50, and the vulnerable? Then we could channel more vaccines to help vaccinate the old and vulnerable in other countries around the world.” You can both answer that, but David Salisbury, do you want to take that one first? Strategically…

Professor David Salisbury

Well, yeah.

Emma Ross

…should we, and what’s the rationale for doing that?

Professor David Salisbury

Well, and the rationale, I think, is straightforward, and once you have protected people aged 50 and over, and those with comorbidities, you will have done an enormous amount to push down hospital admissions, and deaths. You will have done a huge amount. I mean, the numbers, we can talk 95, 97, 98% of the deaths may well have been – well, may well be averted by such a strategy. And in terms of an equitable move, then saying we have surplus vaccine, we ought to give it to people whose needs are much greater., that’s a – you know, a very honourable and understandable position. Whether it happens, I think is a different question, and, politically, that’s not an easy choice to say, “Okay, that’s enough.” We’re not going to protect other people, we’re not going to protect Teachers, we’re not going to protect people who drive buses. We’re not going to protect people who are in occupations like the Police, because they’re not in a risk group, and we’re going to leave them exposed. So, politically, I think it’s difficult.

I think that there is another dimension that people really should be thinking about, and that is the countries who have already contracted for huge volumes in excess of what they will require, ought to be talking at the earliest opportunity, with the manufacturers, about being able to step back from some of those volume commitments, so that that – so that capacity would be freed up for redistribution to other places. There is no need to have eight times your country’s population in vaccine supplies if, particularly, you can see the longer-term is that you may well be using a different vaccine. And I think that there will be opportunity to reconfigure some of those vaccine contracts.

What is very difficult to do is redistribute vaccine that you’ve bought and taken physical ownership of. Once you’ve taken it into your system, it is very much more difficult to hand it onto someone else. But you can much more easily divert from your contract when you know that you are already contracted for a very, very significant surplus over what you will need.

Emma Ross

Yes, David Heymann, can you also answer on after the over 50s and the vulnerable are vaccinated, should vaccine be diverted? And David Salisbury’s right, of course, it’s a political – you know, might be a political minefield. But in terms of strategically speaking of global control, if you were trying to, you know, do what’s best for global control, is that the right thing to do, or not?

Professor David Heymann CBE

Well, I think David’s given a very good answer that, yes, it would be the right thing to do, if it’s possible. But there’s one more dimension that I think David would agree with, and that’s better understanding what the vaccines really do. And if governments understand, from the research that’s going on now, after people have been vaccinated, whether or not this is actually able to prevent infection in people, not just modify infection to less serious illness, but actually prevent infection, then they may find new strategies that they want to use in their vaccination. Perhaps vaccinating populations where transmission risk is greatest to decrease transmission in that population, and throughout the country, and then there might be a shift in their vaccine needs. So, all of these things can be occurring moving forward. But I think that there’s no one – at least, David and I believe, from what I understand David said, that there should be sharing, if possible and feasible, and that we should not oversubscribe our nations to vaccines, and let other nations not be able to get those vaccines, if we have enough, or more than enough.

Emma Ross

Okay, one thing that I’ve just thought of on what you’re both saying, is if we discover that the vaccines actually prevent transmission, would it not then become politically more difficult to give up vaccinating the young or the non-vulnerable, to devote those vaccines to developing countries, if, in your own country, you could prevent transmission by vaccinating the young? They may not get sick, so the whole argument of they’re not at risk is, kind of, a little bit secondary to, we can stop them spreading it? Doesn’t that not then become even more difficult, politically, to argue for giving it up and sharing?

Professor David Heymann CBE

David, do you want to try?

Professor David Salisbury

Well, I think the answer is yes, it does become more difficult if you honestly believe that having vaccine that you can implement at high enough coverage in the non-risk groups and, indeed, is sufficiently effective to stop transmission and it’s the old multiply coverage by efficacy. If you think that you could achieve it, then the arguments for retaining vaccine to stop transmission in your own population become stronger. The big caveat, of course, is the acceptance of being vaccinated by people who are not in risk groups because if they don’t join into the same extent of very high coverage, with highly effective vaccine that will stop transmission, well, we won’t have gained very much using vaccine in a way that might’ve been much more valuable elsewhere.

These are tough, tough political choices and, in a way, the science is not where the argument’s going to be.

Professor David Heymann CBE

Emma, yeah, I would just add to that, that what David says is right, and, you know, we don’t know the length that immunity might last after vaccination. So, all these questions will figure into government decisions. But, you know, there have been people who really are talking about herd immunity, and saying, “Oh, we’ll have herd immunity,” when they don’t even understand exactly what it is, or how you obtain it and, so, what’s very important is not even to talk about herd immunity. I heard you talking about it earlier. What’s more important is to maybe talk about a herd immunity effect, a decrease in transmission, because there’s a number of people who are infected, and won’t be transmitting it to others. Rather than herd immunity, which means you’re having people vaccinated to stop transmission.

Emma Ross

Okay, thanks. I’m going to go onto the next question, I’m bunching two questions together, the most upvoted question, plus another one. And it is from Robert Gardner, who’s asking, “Please comment on the interval between first and second jabs.” And a similar question from William Crawley, “What is the immunological experience behind the decision to extend the time between the two jabs, and to mix the vaccines, even though this has not been tested by the manufacturers? Or is it informed guesswork justified by the need to reach as many people as quickly as possible?”

And I can I just add that in about the hour before we went live, WHO put out a press release on the latest thing from SAGE, their Vaccines Advisory Group, on the AstraZeneca vaccine, that their recommendation is second jab between eight and 12 weeks. So, previously, they had – that seems to be the first time they’re kind of saying that that’s okay. Eight to 12 weeks is better than four weeks, just throw that in there in case some either of you hadn’t come across that. So, who wants to take on the wisdom of interval between jabs?

Professor David Salisbury

I’m happy to try and pick that one…

Emma Ross

Go ahead.

Professor David Salisbury

…up, and the reason will become clear. Let me just knock out the bit about mix and match. I think that the strongest reason for doing some studies on mix and match, where you prime with one vaccine, and you boost with another, is so that you know that you will have flexibility in the future. If, for instance, you have more of one vaccine than another, you see that one contract is running dry, and you’ve got prospects of another. So, I think that knowing about mixing and matching gives you flexibility for the way you use your vaccines in the future.

It might be the case that following one vaccine that you prime, with another vaccine that you use to boost, gives a better immune response than two exposures to the same – you know, the same carrier virus, or, indeed, to the same vaccine each time round. That’s possible. So, there are reasons for mix and match. Coming back to the other – first part of the question, I’ve been a strong supporter of delaying the second dose significantly, before it was announced. And my reason was the simple numbers, and it’s about saving lives, and the more people that you can give first doses to, the more lives you’re going to save.

Let’s go back to the numbers. Vaccinate a million people with two doses, at 95% efficacy, you have protected 950,000. Give a dose to two million people, and even if the efficacy was only 70%, you’ve protected 1,400,000. Our job now is not epidemiological purity, and immunological purity, it’s saving lives and if we want to save lives, we need to vaccinate as many people as quickly as we possibly can. The thing we’ve got to remember is that as we extend the vaccination of risk groups, which, of course, you know, is entirely justifiable, we’re going to get to the point when we need to start giving second doses, if we’ve got an extended interval. So, if we’ve got eight to 12 weeks interval, the people who need their second doses are going to be coming through the UK system, roughly, in mid-February, through to mid-March. And that will double, potentially, the number of doses of vaccine that you will need, if you’re going to roll more vaccine out to more risk groups. And you’re going to need twice as many people doing the vaccinating, or they’re going to have to do it for twice as long, to get through the number of people.

So, you know, these choices are not easy, but the choice of extending the interval, to my mind, was about saving lives. We also know, from other vaccines, that where you have a longer interval, you actually get higher immune responses. So, if we were taking any sort of choice, it wasn’t a choice of less protection, it’s actually a choice to the possibility of better protection, by extending the intervals.

Emma Ross

Okay, thank you. I’m going to ask David Heymann to take the next question, which was from Ella Pickover, from the Press Association, “When do you envision social distancing will end?”

Professor David Heymann CBE

Social distancing…

Emma Ross

Nice question for you.

Professor David Heymann CBE

Yeah, social distancing, or physical distancing, is a way that you can prevent many infections, and not just COVID. You can prevent influenza by physically distancing, and physically distancing occurs either by physical distancing, a metre or more, or it can occur by wearing a mask, if you can’t make that physical distance. Some cultures in Asia have adopted that as always, when they have a respiratory infection, they wear a mask, in order to protect others.

So, what we’re learning now in our societies may be something that will remain, especially in seasons when there’s increased transmission of influenza, we may decide that that is the way we want to proceed. And when we’re riding the tube, or somewhere else, we want to physically distance ourselves from people who might be coughing, or sneezing, and we might, in some way, want to be wearing a mask at sometimes in the future. It’s not clear what will spin off from this pandemic, but what we are learning is that we can prevent infection of others, and we can prevent ourselves from being infected, with this virus, by physical distancing and mask wearing, and, possibly, we’ll want to carry that over in the future to others. Nobody can answer. It will be a cultural shift, if it does occur, as it has occurred in many Asian countries.

Emma Ross

And could we envision that now that we’ve kind of been sensitised to this during COVID, that next flu season, you know, London Transport demands that you must wear a mask during flu season? Or, if you’re saying it could spill-over into other diseases, and our behaviour could be transferred to that, is that something that might occur?

Professor David Heymann CBE

Oh, I can’t predict what might occur. I can say that I think as soon as the government is happy that they’ve had success in decreasing the burden on hospitals, and decreasing mortality, they will start to develop other concepts and other strategies and these strategies may not be so top-down as have been the current strategies. They may be more what people want to do in helping people understand how they can protect themselves and protect others better moving forward. I don’t think anyone can predict. David, do you have any ideas on that?

Professor David Salisbury

Given that we don’t know what this virus is going to do, it is, of course, very difficult to make predictions. I think that there will be behaviour changes, and David’s already identified some of those likely behaviour changes. We will have a much lower threshold to putting a mask on, if we think that we might have an upper respiratory tract infection, or others around us have other – have upper respiratory tract infections. So, you know, those sorts of behavioural changes, and overcrowding in the underground, I think people will be much more cautious about standing, you know, nose-to-nose with someone who you have no idea whether they are infectious with coronavirus, and they may not be symptomatic and they may have been vaccinated, but able to maintain coronavirus infection in their nose.

So, I think that our behaviour is highly likely to change, and we will have to come to terms with some social distancing, some different aspects of the way in which we work. We may not feel every day we have to go to work, if we can actually work effectively from home.

Emma Ross

Okay, there’s another question, it’s equal up – most upvoted, and this is about moral choices, I guess. Mike Wheeler is asking, “Statistics show that 97% of those who have died had pre-existing conditions, and only about 450 people, under the age of 60 have died. With hindsight, has the UK Government induced unnecessary fear about something that affects, albeit seriously, just a defined section of society and is that something that we are all going to have to get used to living with anyway?” David Salisbury, do you want to express an opinion on whether, in hindsight, the UK’s kind of been scaring us unnecessarily?

Professor David Salisbury

I think the number of deaths, the number of hospital admissions, the overburdening of our health service tell us that the concerns are valid and genuine, and I would not wish to trivialise in any way the – that we have been scared inappropriately. I think that the evidence is very clear. The fact that so few of the deaths, thankfully, have been in younger people, and people without comorbidities, comes back into what I was saying about who you vaccinate, and what the choices are, and how well vaccination will be accepted by people who are not in risk groups, who may see very little personal benefit, because the benefit from them being vaccinated is being taken by someone else. And, so, for many young people, acceptance of vaccination may be on a basis of benefit to some – to other people.

Emma Ross

Okay, thank you. We have time for one more question that I’d like to field to David Heymann. But before we do that to our listeners/watchers, we are developing the programme for the rest of this leg, go – running through Easter. But we’re really interested to hear from you if there are certain topics that you’d like to nominate for us to cover, please do start writing them in the ‘Q&A’, and we will be collecting those to consider. We do have a couple of things already scheduled, and, of course, we’ve got our own ideas, but we’d love to hear from you on specific topics. If you’ve been a regular listener, you’ll know the type of thing we look at. But please do put in any suggestions, or desires, in there, and that’ll get to us.

So, I’m going to go onto the next question, it’s a few questions bunched together on the same topic, and it is about equitable access. And one is from Phillip Angelides, and this is for David Heymann, “How can international organisations and country leaders ensure fair access, and equitable allocation of vaccines, particularly in low-income countries?” Linked to that, Sarah Whiley, “There are well-developed programmes, vaccinating against measles, etc., in Western European countries, but these are still serious killers in African countries. What more can we do together to share COVID vaccination as widely as possible around the world? How can we perpetuate the divides of – how can we not perpetuate the divides of poverty and public health that COVID has already highlighted? How can this disease vaccination be different?” Actually, that probably speaks to both of you.

And there’s one that kind of links to what my wrap up question was going to be to David Heymann, which is, “What kind of global action is going to be necessary now?” It seems like – it seems to be filtering in, the enlightened self-interest of sharing vaccine, and ensuring equitable – you know, if we just do more of taking core – care of our own countries, is that going to do it, or what exactly is going to be necessary now? So, David Heymann, do you want to start answering the bit maybe from Phillip? And then, David Salisbury, the question from Sarah about measles and developing countries, and how disease vaccination can be different in developing countries, this time around?

Professor David Heymann CBE

Thanks, Emma. So, yeah, I’ll be happy to start. I think, you know, when we think about vaccines, if we think about the vaccines that are already available, and have been available for many years, there have been mechanisms that have been created that have helped get those vaccines to the people who need them. Some have been eradication programmes, where all countries have worked together to get the vaccines out for diseases such as smallpox, or polio. Then there have been revolving funds that have been set up, for example, in the Pan American Health Organization, where they purchase all vaccines, at a preferential price, for countries in Latin America and they then purchase their vaccines from that revolving fund.

Then there’s the Global Alliance on Vaccines and Immunisations, which has taken upon itself to make sure that countries that can’t afford – the lowest income countries that can’t afford new vaccines get the newer vaccines into their health systems. So there have been many mechanisms created in the past for those diseases, which are endemic and have vaccines. For influenza, which is epidemic seasonally, there’s also been a mechanism, the Pandemic Influenza Preparedness Framework, which is a commitment by industry to provide a certain amount of their vaccine production to WHO at the time of the pandemic, in order that WHO can distribute it for first line workers in countries around the world.

And now there’s the COVAX facility, which is a further step forward, trying to get all countries to purchase at least some of their vaccines through a facility which would negotiate a price. And this would be a failsafe, if you would, for industrialised countries, they could actually purchase up to 50% of their vaccines through COVAX, if they wish to. And, also, for other countries, developing countries, low-income countries, they can then mobilise resources from grants, or loans from the World Bank, or from development agencies, to purchase their vaccines through this facility.

So, there are ways that are being developed. I think what’s very important, though, for us all to understand, is that governments need to be committed to do this. And if governments are not committed to vaccinating against COVID, then it won’t do any good to give them that vaccine. What needs to be done is they need to be engaged in getting that vaccine to people, despite the other priorities that they might have. David.

Professor David Salisbury

Yeah, I think David’s given a great answer, and I was going to come to this very – in a very similar way. You know, we’ve got COVAX, it needs to have more capital, so that it becomes an equal purchaser to the way in which the industrialised countries have been able to get their contracts in place. And, so, COVAX needs to be as big a player as major countries and have the ability to get as much vaccine as it can handle. And then the second side of it is, the countries themselves must make the commitments, and that comes through from their populations, their health services, and their Politicians, that they will avail themselves of all of the vaccine that can be obtained on their behalf and use it. And I think that’s the nearest we can get to having some form of equity, and it will come about if COVAX becomes as powerful a purchaser as some of the major industrialised countries. And, so, it wouldn’t hurt if some of them got squeezed by COVAX outbidding them and, so, they could – you know, they would be in a morally impossible position to complain that COVAX has elbowed them out of the vaccine line, because it’s a bigger purchaser than they are. I’d love to see that.

Emma Ross

Okay, thank you. There was one I wanted to squish in, but I think you’ve kind of answered it, from Phillip Nelson, as to, “How is COVAX doing?” But I guess we kind of did it, but that may be a long, long answer as to whether – do we grant it a success, failure, don’t know yet? Do you want to give a one-liner on how you think it’s doing before I wrap up?

Professor David Salisbury

From me, way to go.

Emma Ross

David, David?

Professor David Heymann CBE

For me, it’s a very important mechanism, and we should all be contributing to it in some way or another.

Emma Ross

Yeah, but how’s it going? We know it’s important, but how is it going?

Professor David Heymann CBE

It’s not been able to mobilise the resources it needs yet. Gavi for – though, has been able to mobilise some vaccines in a stockpile that they will provide. But what’s necessary now is that COVID gets the funding.

Emma Ross

Okay, COVAX. Okay, great, so I’m going to wrap up now, and I’m sorry, there were a few more questions we couldn’t get to. Very excited to see suggestions for other sessions, and thank you both, again, for a really insightful discussion on what’s going on with these two interlinked aspects of the pandemic. And I think it is interesting, David Salisbury, that things that you were raising back in May, last time you were with us, in terms of this not being such a smooth path out of this, have now transpired. And if any of our audience want to see that predictive thing, we have a little highlights reel from 2020 on the Chatham House YouTube Pandemic Briefing playlist, that kind of rounds up our guests over the course of the last year, with some of the highlights. And a lot of things seem to be ahead of the curve back then, it’s really amazing for me to see.

But thank you all for joining us, and David Heymann and I are going to back in about two weeks to explore the issue of border controls and getting back to international travel. But before then, have a great rest of the day, and couple of weeks, and thank you both, David Salisbury, and David Heymann, as ever, and thank you all for tuning in. See you.

Professor David Heymann CBE

Thank you.

Professor David Salisbury

Thanks.