Coronavirus (COVID-19): Press Conference with Barry Bloom, 05/13/20

You’re listening to a press conference from the Harvard T.H. Chan School of Public Health featuring Barry Bloom, professor of immunology and infectious diseases and former dean of the school. This call was recorded at 12:00 pm Eastern Time on Wednesday, May 13.

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


BARRY BLOOM: I’m looking forward very much from these conversations, very, very stimulating and tremendously impressed with the thoughtfulness of the questions. And I’d rather answer questions than give a speech. So, I would just say I’m ready to go.

MODERATOR: All right. Thank you, Dr. Bloom. First question.

Q: Hey, Barry, how are you? Question for you regarding antibody testing. What is the reliability of antibody testing given that it’s that something cities and towns should be looking into?

BARRY BLOOM: As you know, the FDA allowed over a hundred antibody tests to come into the country without validating them, asking the companies mostly from China to say that they could run multiple tests, and they had the ability to distinguish between people who had been unaffected by COVID and those that were COVID positive, and they found the tests were overwhelmingly unreliable.

They have whittled it down to, I think, 10 tests that have been approved and except for one or two at most, these are not your take home test that looks like a pregnancy test. These are tests that have to go to a qualified lab to do ELISA tests. And my understanding is the top ones are essentially 100 percent negative in people who are bleeds before they had coronavirus infection and essentially ninety nine point some percent positive of those that have recovered. And that’s the level of specificity we really need.

It has to be that high. Because you don’t want to tell someone that they are positive and likely immune if the specificity is poor and they’re picking up cross reactive antibodies from the common cold. That would be a very bad outcome. And conversely, you want to be able to detect even early cases or mildly symptomatic cases.

So the sensitivity has to be able to pick up as many people that are actually infected or have been infected as possible. So I think for the first time, we now have a fair number of tests. They are not in your local drugstore and they’re probably not so easy to get samples to. Institutions are more likely to be using them for research purposes at the moment than people running to see whether they are antibody positive. That’s about what I can say.

Q: So I know Brookline is going through testing right now. They are testing six hundred people but there are holdups on the federal level, federal level, trying to get those tests approved. So given where we are right now with the tests, is this something cities and towns should be trying to go for?

BARRY BLOOM: To be honest if they can set up their tests – these are not the most complicated tests in the world. They are used for a diagnosis of many infectious diseases. There are many hospitals that can carry out these standard tests. If you’re talking about mass testing, I think there are limitations in local hospitals and you would send them to Roche or one of the major diagnostic outfits that can do thousands a day. I’m not sure for the moment we need thousands a day. We really need to know what they mean.

And we need to know, for example, of people in the community that have never been sick, have no evidence of infection, whether they, in fact, have been infected and whether they are resistant to re-infection. Those are the two very main questions. As you know, there was a study carried out in collaboration with Columbia Medical School on how do you find kind of neutral test population that should have no obvious reason to be exposed. So they look at the maternity ward of others at Columbia and Yonatan Grad at our school did some of the epidemiology. What was surprising there was about 12 percent of perfectly healthy pregnant women who showed up with antibodies.

And the value of the test is it tells you at the level of community infection that there has been, which in this case was higher than one expected for a perfectly normal population going to a hospital in the Upper West Side of New York City, which is the hot zone. So epidemiologically, it will be very valuable to know where the hot spots have been and may still be. It remains to be seen that we follow these people long enough to learn whether they have been re-exposed and resistant, which is what everybody really individually would like to test for.

Q: Thanks, Barry.

MODERATOR: Next question.

Q: Hi, Barry, thanks for doing this. The attention is focused now on reopening a wide array of different places. And I’m wondering, what is the likelihood to your mind that cases will rise and we will have to reimpose some sort of social distancing controls? And if so, how would that second round of distancing be different from what we’re doing now? What lessons might we have learned in this round that we could apply in a second round?

BARRY BLOOM: That’s a question you should be asking the mayor and his advice counsel. As you know, there are four steps in Boston that have been outlined, but none of the details are clear, exactly which businesses and which categories of work would be opened and what the methods for testing and being assured were. So those of you who watched the Senate hearings yesterday heard from Dr. Fauci that basically everywhere that has clamped down has had a flare up at some point and there are various excuses for that, but I think what Tony’s point was very clear.

We don’t know anywhere in this country exactly how many people are infected, particularly with an even unknown percentage of asymptomatics that are capable, presumably, of spreading the disease. So we’re really working in the dark to say what it’s likely to happen and when it will happen.

The professional view, as I understand it, is this epidemic will be around for a long time. If the brakes are lifted at a gradual level, the major concern is that it will flare up to a level that will challenge our hospitals again. And that’s the goal of bending the curve. Bending the curve means you spread out infections over a longer time. It doesn’t necessarily mean people who stayed at home are anything but as susceptible the day they go out as the day they went into lockdown. So the major concerns are to loosen the controls when you’re pretty confident whatever happens, even if there’s a five fold increase, the hospitals in Boston area will not be overwhelmed and we’re prepared to save lives if that’s what’s necessary.

I think the second concern is that it be done in a gradual enough way once the numbers are down and that’s the testing issue, that there’s a good chance we could catch most cases and identify the chains of transmission by contact tracing, which is, you know, is now more advanced in Boston than anywhere else, thanks to Partners in Health. And if you stop the train of transmission, put everybody who’s been in contact in isolation or quarantine for 14 days, that chain of transmission stops and the curve should go down. Ideally, you don’t want to lift constraints until the numbers are down low enough that you have a good chance of identifying cases in context. And we’re probably not there in Boston. But I’m certain in western Massachusetts and in Montana and Vermont, the cases are low enough that if you have 50 cases a week, it’s not too difficult, or fewer, to track down the cases. And most of their contacts and that’s the concern.

Q: Is there enough conversation going on to your mind about what might happen after these restrictions are lifted and what might, what steps might then need to be taken?

BARRY BLOOM: I think I think there are two, really two scenarios. One is you get a big burst of cases and I would guess we are prepared enough here that’s unlikely to be the problem. You’ll get a burst, but then the city and the state would know about it. And they would probably have to reinstitute social constraints again. The epidemiologic model that is least painful is to have slow release of opening of various categories of buildings. And if any building or any business has an outbreak, to be able to track everybody at that time and place and find new cases. I remind you, at a major biotechnology company two visitors that were perfectly asymptomatic came, went to a meeting of one hundred and seventy five people, and four weeks later, ninety nine of those hundred and seventy five were infected. So that’s the level at which I think we can hope things to happen after they loosen up. There will be small flares, small outbreaks, and we would be in a position to identify those outbreak areas and keep the number from flaring into something that would require a systematic reimposition of social distancing controls.

Q: Very good.

BARRY BLOOM: I point out only that two of the other places had done a really superb job. Korea, for example, that was testing 15,000 people a day before we had anybody that’s other than CDC able to carry out testing in this country, has had a flare up from a bar where someone, one person apparently carrying the virus went into multiple bars and led to a significant outbreak in Singapore, which had done perhaps the best job, failed to acknowledge they had thousands of workers in dormitories, which is the same as nursing homes and prisons. And they have been enormously occupied with trying to control that outbreak. While fresh cases elsewhere in Singapore are almost zero. So we could expect outbreaks and we could expect to try to contain them.

Q: Very good. Thank you.

MODERATOR: Next question.

Q: Thank you very much for doing this. I was curious about sort of what’s going to happen with a vaccine once we have one that we think sort of works wells or we have a couple that we think sort of works well. This morning, the CEO of Sanofi said that BARDA or that the US would get its access to its vaccine if it works because BARDA had invested in it. And we’ve also seen some other companies say that the UK will have first access there. Is this a fair way of distributing vaccines and to say who will get first and what would be a fair way? Is there a plan, I guess, to get it to much of the rest of the world’s where there aren’t any companies that are building these? Thank you.

BARRY BLOOM: A really important, profound question. And I would say, first of all, I appreciate your raising it. And I would urge other journalists to think carefully about it. In a real sense, there has not been a serious conversation about the answer to that. Everybody has been fixated on when we’re going to have a vaccine. And the answer is there probably isn’t going to be a vaccine. And I could argue that that’s quite a good thing, because probably no one company has the capacity to make seven point six billion vaccines for everybody on the planet. And so we will probably need a diversity of vaccines. The second is, if there was only a single vaccine that comes in and wins, first, you’ll have a monopoly situation where there is no opportunity for people in low and middle income countries to come anywhere near the head of the line.

And so W.H.O. has been very concerned, as have been many of the scientists, to say how do we deal what will inevitably be a limiting dose of doses of vaccines? The target for the big companies in this case for pediatric vaccines is to make three hundred doses if you can. Many make one hundred million doses for kids. We’re talking about billions of doses being required. Many of the candidate vaccines will require more than one shot. For example, Moderna is doing two shots and other vaccines, they will need two shots. So that’s double the amount of production, double the amount of time to get enough vaccine. And the question is, we need a conversation, a discussion to figure out what is fair.

There will be disagreement. There’ll be many who believe that because BARDA has supported three vaccines, they should all go to the US because we paid for it. And what happens then to the rest of the world? What is the image of the United States and the rest of the world if their plan is strictly for them. I was gratified that the director of NIH, Francis Collins, has created a plan – I think it would have been great to have it a little earlier than now – called ACTIV, which is a consortium way of planning for what to do to raise the number of vaccines, distribute the number of vaccines, and in that early formulation and which was, I think just yesterday, thinking seriously about how to do a plan that makes it fair in this country as possible.

For example, everybody seems to agree that health care workers who are facing patients daily and the risk of infection very much deserve to be at the head of the line because they will continue to be facing patients. I haven’t had anybody argue that second in line, I haven’t heard any arguments, should be the people driving the buses or sweeping the floors or working in the supermarket before the titans of industry, or even the lowest of the priorities, in my view, would probably be academics who can work from Zoom. We haven’t had that discussion. I don’t think decisions have been made. And I think without public input, there’s going to be very distrust if the government makes all those decisions on its own.

And I think the press, this is an area where the press can press the leadership in vaccines in this country, both companies and the government, to think seriously, get input and get a solution that doesn’t leave America dissatisfied that every segment feels that it hasn’t gotten enough. And this mass distribution, we talk about when are vaccines going to happen. A vaccine is not a vaccine candidate. A vaccine is a vaccine when it’s shown to be safe and effective. And that’s after there are a thousand for – each vaccine, in my view, is somewhere between six and twelve thousand people to do an efficacy trial. So there is serious thought under way of how to do efficacy trials after phase 1 shows that it doesn’t hurt anybody in the first 50 or 100 people.

The second level, phase 2 trials is to say, do we get 500 or 600 people? And do we not see any adverse effects? And while we’re at it, do we find out that they’re all making antibodies or the antibodies neutralizing? Do they appear to be the kind that would be protective? And then after that, it will get permission for moving into phase 3. Those are traditionally sequential and the planning as I understand it now, is having a continuum. So it’d start with 10 vaccines. If one of them proves to be safe in the first hundred people, you go to phase 2. If two of them don’t develop neutralizing antibodies or any other evidence of protection, you drop them and the others move forward into phase 3. If adverse effects appear, they drop out and you end up with a smaller number, perhaps five or six producers where you can get enough of each of them can produce between 300 million and a billion doses.

That’s how I see this playing out and I am pleased that the NIH is planning on how to make what wouldn’t ordinarily be central, ordinarily be segmented and separated in time, phase1, 2, and 3 studies to be continuous as long as things are safe and there are signals that might indicate protection. Nothing’s been done ever before like that. I think the obvious question, which I think the press also should be asking is as we compress the time frames for doing that, the way we do that is get larger numbers to get safety signals. Can we be certain that safety, because vaccines always go into healthy people, that they will be as safe as any other vaccine that would have been done?

And my impression is everybody that I’ve heard from companies and everybody from NIH and the other government agencies, BARDA, are well aware that given suspicions about vaccines, adverse effects early on in this process would be devastating because companies are making billion dollar investments upfront without having the vaguest idea whether their vaccine would be effective and safe on large numbers of people. So an unsafe vaccine costs an awful lot for everybody. So I am not expecting any compromise in safety, but that’s going to have to be pressed on the people doing it so that the public can be as reassured as it is possible that this will be as safe as every other vaccine. As most of you know, the target for childhood vaccines, not always achieved but mostly achieved, is no more than one adverse effect in a million immunizations.

MODERATOR: Did you have a follow up question?

Q: Yeah. Thank you very much. That was really thorough and great. Do we have any sort of precedent for this in terms of even on a small scale getting the vaccine to a large population somewhere else in a very short amount time?

BARRY BLOOM: No. There is no precedent. And part of the reason is there’s no precedent for what the major strategy that has taken the lead, which I think deserves some credit in the press as well. This is perhaps sounds irrelevant, but I think not. In 2001, 9/11, we were devastated in this country by two bits of terrorism, the World Trade Center and anthrax shortly thereafter. The National Academy of Sciences decided that this country was highly vulnerable to both manmade threats and natural threats, pandemic influenza being the case that was in mind. I was a co-chair on the Bio Security Council that wrote a report called Making America Safer. And there were a series of recommendations that said a) we’re unprepared and there are ways to get prepared. And what we wanted to be prepared for primarily was pandemic flu.

In 2009, there was a national pandemic flu plan that was upgraded multiple times. We had swine flu in the meantime, and there is something called the National Pandemic Influenza Plan that said how all 17 government agencies involved in an epidemic should be able to interact and do their thing, which was in pretty good shape up until 2016, where much of it was not maintained and has dissipated in terms of interaction and planning and having the states on board. But there was a plan and one of the parts of that plan, as recombinant DNA technology developed, is maybe we don’t need to make vaccines the way we always did. One bug at a time, one protein at a time from one bug at a time. And that led to the creation of BARDA. And BARDA’s goal after it was put together and they focused on things other than smallpox and anthrax for the national stockpile, which they did pretty well, was to say we want a vaccine candidate in 60 days. And the head of BARDA actually came to a course that I was involved with and said that and I almost fell off my chair.

And in fact, in sixty two days, the Moderna vaccine was put into people’s arms in Seattle. So BARDA has really led with the idea that we don’t focus in this context necessarily on the bug of the week. We focus on platforms. RNA is made quickly. It can be made for any viral antigen from any virus. DNA can made quickly from any virus. Adenoviruses can have a gene for their surface antigens replaced pretty much by genes from a related virus, a membrane virus. And so what we have now is platforms where there is simply an ability to go from a DNA sequence to a recombinant material, either RNA, DNA or of recombinant adeno-5, adeno-15, adeno-26, VSV. The French are doing measles. That’s never happened before and that has made this something that is possible to do, to have a candidate in 60 days. Never have we been able to make a vaccine earlier than four years, from the time it was put in to testing to approval by the FDA.

That was mumps vaccine, if I understand it correctly. The longest was twenty seven years. So to have a vaccine, an 18 and sixty two days into people with the expectation we will have Phase 2 data on perhaps the immunologic correlates that might relate to protection and a little more safety data in perhaps a thousand individuals and a go or no go decision to move forward and continue expanding that into Phase 3 over the summer. All of that is absolutely unprecedented, but I do not believe anybody involved is thinking in the slightest of compromising safety.

MODERATOR: Thank you, Dr. Bloom. Next question.

Q: I just had a, I had a question about the role that the CDC has been playing throughout this process. And, you know, Mitt Romney was also bring this up in the Senate hearing yesterday about how do we get to this point where we don’t, so we don’t get into this situation again, which was his question to Dr. Redfield about data collection. I’m wondering if you can explain what’s been different about the CDC this time regarding the kind of data that they’re collecting from what we usually see in infectious diseases? And why have there been so many inaccuracies or just inadequate data collection from what we’re used to?

BARRY BLOOM: I have absolutely no idea how that happened. One can speculate. I would prefer to stick to the data. As you know, CDC collects data from every major CDC office in every state and in many cities. New York City, for example, is treated by CDC as a state. They had to have been getting data and evidence and why it was left to Johns Hopkins to put all the data from the US and the rest of the world together, I cannot have any idea, nor do any of my colleagues fully understand that.

I think one thing I can say, at least when I had been on the advisory committee, the scientific advisory committee to the National Center for Infectious Diseases some years ago, one of the differences between CDC and NIH was when a scientist at NIH writes a paper or a grant recipient writes paper, they write a paper and they don’t need permission from Dr. Anthony Fauci if they’re in NIAID or Francis Collins to send the paper off to a journal. That is not the case at least then and I would guess now is not the case. Every single paper had to go through and be cleared by the director’s office even in the early part of this century.

So, yes, outbreaks and infectious diseases have grave economic consequences unless their communications are carefully thought out and planned. But I would wonder why the data that the CDC must have had was not posted on a website and why we had to turn elsewhere. And I think that’s a question that has not been answered in that discussion yesterday.

MODERATOR: Do you have a follow up question?

Q: I guess we’re wondering also what some of the consequences are of inadequate data. I don’t want to put words in anyone’s mouth.

BARRY BLOOM: I know this is a recording and my dean may kill me for this, but God bless Johns Hopkins for this [laughs]. They have done an extraordinary job in the biosecurity center at Hopkins, both collecting data that may or may not be available to CDC from other sources, hospital sources that don’t necessarily in various parts of the country go through the local health departments or don’t get there right away.

So to be honest, I’m not sure we’ve been short on data in the American public, but had they not done that, we would have been far greater in the dark. And as you know, the CDC numbers and the numbers at Hopkins are not identical because Hopkins does try to get other sources that are not official government sources for the CDC, from independent hospitals and stuff like that.

So I, with all due respect, am disappointed that CDC was not the center of the universe as they have been in almost every other outbreak, including Ebola, providing information, telling people what they could expect, what’s true, what’s not true, dealing with rumors. And they have been in a closet in this case up until very recent.

MODERATOR: Alright, thank you. And I will say – I’m not going to counter Johns Hopkins here and toot our own horn – but I’ve also got a lot of appreciation for all the amazing faculty at Harvard and how much you guys have been available to everybody and really stepped up. So thank you. Alright. I’ve done my piece as a media relations manager. Next question.

Q: Thank you. We’ve been seeing escalating tensions between year-round residents and second homeowners or visitors, especially coming from hot spots. And it seems we don’t have enough data to indicate to what extent people traveling are bringing COVID-19 with them. So, my question is what data do we have and what should people consider before traveling to second homes or the family’s summer vacation?

BARRY BLOOM: Gee, that’s a really interesting question. No one has asked me that before. I think the name of the game is that we’re going to have to go back to something approximating life as we knew it, but it will not be the same for a very long time. We have no rules in this country for restricting travel from Boston to Cape Cod or from anywhere in Massachusetts or Atlanta to Wyoming and Montana and Vermont. And I can’t imagine tolerating that. As you know, there were protests when Connecticut was stopping cars coming from New York City to try to find out whether they could stop the epidemic. So people are going to move.

I think the expectation of the epidemiologists, that’s what’s going to happen. That’s why the expectation is there will be increases in cases and there will be spread. But the history of outbreaks and epidemics is by the time we know they’re there, stopping travel, even international travel, is too late. In other words, every case that we see today was set up between 2 and 4 weeks ago.

So if we can’t test for people being asymptomatic carriers or spreaders, people get in their cars and are going to travel and all we can do is a) hope people walk around with masks, b) we hope that people will abide by social distancing in whatever facilities they can. The expectation is that restaurants and public gathering places will probably be doing different things than they used to. But I believe we have no capacity to really restrict travel without reason. And as a consequence, they will bring – if it is not already there, they will bring it to their communities and we just have to be on guard for it.

Q: So for the people who are leaving hot spots like Greater Boston, New York City or Fairfield County, Connecticut, to try to escape the virus, can we confidently say that they’re safer in the areas they’re going, which are often more rural?

BARRY BLOOM: Yeah, I think that one of the major variables is density, and one of the things is that if you stay in a student dormitory on Cape Cod, your risks are higher than if you have a small house half a mile away from someone who is a neighbor. That’s obvious.

Q: Thank you.

MODERATOR: Next question.

Q: Hi, Professor. So my question is really related to the previous one. So what role can W.H.O. play in dealing with the roughly unequal geographic distribution of manufacturing capacity for COVID vaccines as well as the deals that are being struck between companies and other manufacturers? Actually, I want to listen to your opinion on this.

BARRY BLOOM: So let me see that I captured the question. The question is –

Q: What role can W.H.O. pay in dealing with an unequal distribution manufacturing capacity for COVID vaccines?

BARRY BLOOM: So I think W.H.O. is trying to do a couple of things that I think they have never some of which they have never done before. And the first thing is daily briefings for the public to tell the global public, many of whom do not have reporters on top of what goes on in every nook and cranny of the 194 countries that make up the World Health Organization.

So they have a huge information role and they have a huge advocacy and trust role. They have, as a matter of that role, made strong advocacy that whoever, whichever of the rich countries is first, second and third to develop vaccines, it would be morally wrong not to be able to be able to provide it to people living in low- and middle-income countries, which W.H.O. is deeply committed to serving as their CDC, if you will. And in that context, how do you do that? And one of the ways which they have already done is to create a global drug testing program for therapeutics. And the logic is, if you want to know if a drug works and if it has adverse effects, clearly the more people you test it on quickly, the bigger the power of the study statistically, the more rapidly you will get an answer.

And so they are testing for putative drugs in multiple countries around the world in a program they called Solidarity. And there will be cases in hospitals, in multiple countries that have agreed to a common protocol of what to measure and when it is over, there will be big numbers and hopefully we will learn which of those therapeutics – one of which is remdesivir, by the way – which of them work and in what countries and contexts they work.

The second component of that is if people have been volunteers in clinical trials in multiple countries, there is a moral responsibility to provide them with drugs. It would be morally wrong if there are no drugs to be able not to be able to provide the drugs. So W.H.O. has been really very active in creating a circumstance where they are contributing to research knowledge. But those volunteers in research also deserve to be considered for receiving drugs. And now they have more recently planned to expand that when vaccines become available to be able to do testing of vaccines again like Solidarity in multiple countries, hopefully with common protocols.

You will notice the W.H.O. and major European countries and donors had a meeting on May 4 in Europe to plan for massive levels of fundraising to be able to provide vaccines for clinical trials in many countries. And regrettably, the United States of America, which was invited, was not represented at that meeting. On the other hand, Francis Collins in articles recently indicated that the US is working with W.H.O., intends to work with multiple companies and has also the moral responsibility once there are vaccines to find ways to make it equitably distributed in different parts of the world. It would be nice if it was a single universal collaborative dialog. At the moment, that appears not to be the case. I hope I’ve answered your question.

Q: Yeah. Thank you. So I’ll just a quick follow up, so what is the main challenge or difficulties for W.H.O. to help the vaccines in the future to be used in developing countries like African or South American countries on a large scale?

BARRY BLOOM: So W.H.O. is a normative organization, not an implementing organization. Normative means they set the rules, the guidelines. They are the last word on the definition of what the case definition of diseases are. They have done extraordinary things in outbreaks and epidemics training people. But W.H.O. does not deliver vaccines. For children’s vaccines, that’s what UNICEF does. For vaccines and drugs, for AIDS, TB and malaria, that’s what the Global Fund does. For children’s vaccines, making them available to countries, that’s what GAVI does. W.H.O. sets rules and standards and guidelines, does not have the money or the personnel to be able to deliver anything by itself. What it can do is work with other agencies, U.N. and companies otherwise to encourage help, standardize normalized supply chains. But W.H.O. does not deliver vaccines anywhere.

Q: Oh, thank you. Yeah.

MODERATOR: Next question.

Q: Hi, thanks for taking my question. I have a somewhat broad question just about the long-term trajectory of the pandemic and in terms of whether it will return as a seasonal virus or become endemic in some way. So I guess my question for you is just in the short term and long term, is there a chance that this virus is going to go away, as the president has said? And what is the likelihood of what is your opinion on what the most likely scenario is in terms of moving forward?

BARRY BLOOM: So let me start with a note of humility. Yogi Berra once said It’s really difficult to make predictions, particularly for the future. And that is where we are at any level from a scientific point of view. There are lots of models that have different assumptions of how things will work after this spring and summer.

I think most of the epidemiologists at our place and elsewhere believe there may be a dip in transmission, partly because the summer may be warm, partly because people will be outside of their households in more open air activities. So there may be a dip. I don’t think people think it’s going to go away over the summer. And I don’t know if anyone in the epidemiology business that believes it will not be here in the fall.

So it is likely to come back in the fall and the concern is can go back in two ways. One is if we just forget social distancing and say by the end of summer after Memorial Day, we won, declare victory and go back to where it was before. I think there’s a high degree of expectation there will be another burst of really big outbreaks, particularly since the virus has had time to spread in every nook and cranny of the United States. I think beyond that, then there’s a lot of speculation as to whether if we had a vaccine and you could get 60 to 70 percent of people protected with a vaccine two years from now. That’s the critical number for herd immunity, a term that I dislike intensely. The proper term should be community protection for two reasons. We’re not cattle and referring to people as herds, I don’t think is respectful, but much more seriously, the people who are protected by herd immunity, that is when sixty to seventy five percent of people are vaccinated, the people who are protected are themselves not immune. They’re walking into a room where everybody else is immune and hence unlikely to be infected. But if you don’t get the vaccine, you are not immune.

So the hope is that with community protection, once there’s enough vaccine to get to 60 to 70 percent of the people, there’s a good chance the epidemic will either disappear or become a low level seasonal occasional outbreaks in places that don’t get vaccinated. That’s what I think is the long term guess. There is a possibility with a vaccine that it will completely go away. But that means an awful lot of people of a 7.6 billion on the planet, or the 5.6 billion that would be required to get to 60 to 70 percent protection, would have to have access to a vaccine. And that will not happen in two years.

Q: Thank you. And so do you see the virus going away without a vaccine? Is that – 

BARRY BLOOM: I don’t. I think the best one would hope without a vaccine is that we would slowly let people out so that the cases that are found can be detected, isolated, hopefully not be very sick. Hopefully we would have a drug much before vaccines would be generally available, so people that get sick would be treated with antiviral agents, wouldn’t have to go to hospital, wouldn’t get intubation, wouldn’t require us the kind of severe acute respiratory disease treatments that are necessary if we could prevent people from being very sick and dying with drugs.

But that doesn’t make the epidemic go away. If you come out of a hospital, it’s great that you have survived and aren’t dead, but you change the epidemiology of the infection essentially by being one more resistant person out of three hundred and sixty million people. So that’s the expectation – the virus will be here until we can make it go away.

The best hope is that it will perhaps attenuate and come back on a regular basis, but no worse than seasonal flu and maybe ease in common cold viruses. It’ll be around, but it’ll produce only mild illnesses as more and more people have had subclinical infection and some level closer to the 60 percent herd immunity develops over several years. I don’t see us getting to 60 to 70 percent from natural infection unless we have a big spike in the fall and an awful lot of people get sick.

Q: And the attenuation that you’re mentioning is that only through built up immunity, are you talking about some other mechanism?

BARRY BLOOM: Well, the hope would be my favorite epidemiologic study, which I think almost no one pays attention to and it’s a total irrelevancy to what you guys do, but I just think it’s a fascinating paper.

Australia wanted to get rid of little animals that were eating their crops called rabbits. And it turns out there’s a virus called myxomatosis that is lethal for rabbits. And so they decided they were going to have an introduced infection because the economics of agriculture was really being devastated. They would release this virus and kill off all the rabbits. They had a brilliant epidemiologist named Frank Fenner, who was tremendously important, actually, in the smallpox planning and outbreak and how we wiped out smallpox globaly, who said if we’re going to release this to kill rabbits, why don’t we do it as an experiment and see what happens to the virus and see what happens to the rabbits? And in an absolutely classic set of papers, they put rabbits in quarantine so they couldn’t be infected any longer. And at the beginning, from the field, they put a virus in the freezer. So it was frozen as in the original state. They put a monitoring posts all over the company country for surveillance and then they released the virus and collected rabbits and virus.

And the bottom line is, at the end of the two years, they killed a lot of rabbits, they isolated the virus, they took the rabbits out of the secure facility and challenged them with the original virus and the virus from the field, and they challenged fresh rabbits with virus in the field and the original virus. And the result was incredibly powerful from my point of view as a teaching exercise. The rabbits became resistant and the virus became attenuated. So the virus was less able to kill those rabbits that had been isolated for the whole time, much less effective than the original virus. And the rabbits, when you gave them the original virus, had become much more resistant. And that’s the natural history of an infectious disease if it goes long enough. And by the way, the virus was not totally eradicated. That’s a hard thing to do even in a natural infection like this.

Q: Thank you so much.

MODERATOR: Next question.

Q: Hello. Hi. I would like to go back to the legal terms of vaccine research. So I tried to ask the question to funding agencies, including BARDA and CEPI – CEPI’s an international consortium where donors come from different countries. And so we ask what kind of agreement have they done with pharmaceutical companies that they’re supporting, which which entity is going to hold the right to license the vaccine, if the pharmaceutical companies have the right to set the price, and in the case of companies like Moderna, which is funded both by BARDA and by CEPI, it is funded both by the US and by European countries. So in this case, which of the country would have the right to use the first vaccine, the US or the other countries?

BARRY BLOOM: I don’t think to my knowledge, I think that certainly anyone who has received funds for CEPI has probably had and I don’t know this, but I would assume so since I know some of the people involved, they would have to have a commitment to make the vaccine available to countries outside their own. At what timeframe and when? I don’t know.

Moderna is a US company. I believe that they will certainly have to provide vaccines for people in the United States if it’s turned out to be safe and effective, which I remind you, we do not know. As you know, they don’t have the capacity to produce billions of doses. So they’ve just engaged a Swiss company which is creating a facility to make large amounts of RNA vaccine in the United States. So my guess is that there will be production of various vaccines funded by CEPI and NIH. Probably US producers will produce for the US, if I had to guess, initially and overseas producers will produce overseas, but I don’t believe there’s a rational plan of organizing that until anyone knows what vaccines are going to be safe and effective and can be produced in large amounts.

I think again, the conversation needs to be had. I’m sure CEPI is very keen to see that recipients fulfill their obligation to make it available, but I’m not aware of any globaly agreed upon plan. I would like W.H.O. to be a focus and get buy in. It is not clear at this time when the US is not in agreement with W.H.O. on other issues that we will be party to those discussions. And I think that would be a tragedy.

Q: Well, since Moderna is funded both by CEPI and BARDA, then if there’s no agreement now, it might happen that it would be a kind of all kind of legal issue between the US and other countries.

BARRY BLOOM: I don’t think so. I don’t think it depends on how many dollars was put in by BARDA and how many dollars was put in by CEPI will determine how many vaccines go outside the US and how much will stay in the US. I think that’s a decision that will have to take a negotiation with Moderna or any other company.

But I take the NIH director at his word that there is a commitment by the United States government not to be a monopoly on any vaccine to only provide it to Americans. We would lose such respect and credit in the world. I don’t think that’s a feasible outcome. So I wouldn’t expect a battle between CEPI and NIH, or BARDA. I would expect they would convene on how best to do it for whatever vaccines come forward.

Q: Thank you.

BARRY BLOOM: That decision, in a way, is the companies’, they are the ones who make the vaccines. Other people pay them, but they have the vaccine. So this is a complicated negotiation, not just between funders and perhaps W.H.O., but the vaccine companies and their shareholders who also have to be part of these discussions. And I think it’s again important for you to raise those questions, because I don’t believe they’re addressed at the moment and probably won’t be until those that pass high levels of safety and efficacy are ready can be thought of to be made up in the billions of doses.

MODERATOR: Next question.

Q: Hi. How are you? Had a question about asymptomatic spread. You might remember during the Zika virus scare, scientists are pretty clear and confident that it was something around 75 percent of people wouldn’t show symptoms, wouldn’t know they even had the disease. Do you have any sense of the proportion now in this health scare, COVID-19? Seems like numbers might be all over the map depending on where you study it. Just want to know if you have a sense of the percentage that are asymptomatic and why that’s an important number to know for policymakers as we move forward.

BARRY BLOOM: It’s a really important number for policy numbers because we know how many people are in hospitals. We know how many people are basically sick. We don’t know how many have mild symptoms and don’t go to a hospital. And they probably are at high risk of transmitting it to family members or if they go to schools, to classmates and whatever. And then there are people who are perfectly asymptomatic and we don’t even know whether they have very large amounts of virus and when they do.

So what’s appearing in the last couple of weeks is that people seem to be most infectious at the early times, even before they’re seriously ill. And once they’re in hospital, the viral load seemed to go down as the people develop their own antibodies, even those in hospital that are in the process of getting better on their own. So why are asymptomatic people asymptomatic? Is it because they have already made an antibody response that’s protective? Or they just got a small viral dose and their immune system, innate immune system can handle it?

This is why we need good serologic testing in large numbers of representative people. So as you know, there was a survey done from Santa Barbara, California, of serologic test where they tried to get what they thought was a representative population, which was people who responded to a Facebook request and agreed to do serologic testing. And the number came out, I think, to something like 12 percent, the pregnant women in New York was about 14 percent. All of those are criticized because they’re not represented. They don’t represent most of us who were locked up at home. So the number could be a lot lower or it could be in certain places in downtown Chelsea, the numbers could be 25 percent.

The only way to get the answer to your question is to have validated tests and a wide representative sampling, which people are beginning to think about. How do you get a representative population? And that has to be, I think, geographic neighborhood district level data. If one looks in the Midwest, for example, there will be a big difference in rural areas and major cities except for those rural areas where people work in the agriculture business, where all the conditions are like nursing homes, prepared for an epidemic in each of those places, that then spreads to the entire town. And as you know, the top five places in America that have the highest per capita number of cases at this point are small towns in the Midwest because of agricultural industries that are housed in those towns.

So it’s – the only way we’re going to know what you’re asking is how many people are asymptomatic that have the virus is probably by serologic testing. I don’t think we’re going to be testing every man, woman and child on a regular basis for whether they have the virus, unless we have a simpler, cheaper test.

MODERATOR: Next question.

Q: Thank you so much for four for talking us two is very interesting talk. Thank you. Thank you at the outset. I have thought of two quick questions when we’re looking at the mortalities, for example, coming out of sub-Saharan Africa, I think they’re running at about 3000 these days, which is roughly one fifth of the mortalities that come out of Brooklyn. I know that there was a lot of talk at the outset that sub-Saharan Africa would be particularly vulnerable. I mean, it’s a region without the kind of capacity that Europe has for ICUs, has no real ability to enforce a Chinese style quarantine. Why is Africa doing so well? And what’s your prognosis for the future?

BARRY BLOOM: It’s a great, great question, and I am again asked to speculate on things that I really I don’t think anybody absolutely knows. Let me just say the simplest explanation for India, which again has been doing remarkably well, and the data coming out of sub-Saharan Africa.

Two points. First, it’s early in the epidemic in sub-Saharan Africa. So we don’t know – the cases are still rising in many places. I don’t think they’ve come anywhere admitting nearing a peak. But I would just point out two things. The demography of sub-Saharan Africa and India is very different in the US. 17 percent of the population – I know India better – is under the age of 14. Kids are not dying of this disease except for a very small number. They get this very worrisome syndrome that’s quite serious. But in terms of overall contribution to mortality, children have been at the absolute lowest level everywhere. And young people have been twenty to twenty, fourteen to twenty four have been extremely low. When you ask for the people who need hospitalization, intubation, ventilators, those are people over 65. Again, in places like India and sub-Saharan Africa, that’s a very relatively small percentage of their population.

So those are mitigating factors that says the people most susceptible in the population are skewed to rich countries like the US with an ageing population. Japan perhaps even worse. And there is a lot of hope that they will be the spread of infection but hopefully not so many people with serious disease. There are other possibilities in that an awful lot of sub-Saharan Africa is rural and there may be isolated villages that get wiped out by this virus, but it’s unlikely to spread that far. The worry in a place is major cities, like Nairobi, for example, these are very high-density places. And as you know, even in the States, it’s high density areas and areas of vulnerable people with other medical conditions, which is primarily aging people that are most vulnerable.

So it may be it’s going to be tough on the cities. I think they are prepared. They’ve seen what’s happened in the world. I want to put in a plug for W.H.O.. In the middle of February, in the beginning of February, at the end of January, there were only two centers in Africa capable of doing a COVID-19 diagnostic test. In the middle third week in February, there were 11 centers in Africa trained by W.H.O. for two weeks that could do those tests when in the United States, the only place able to do those tests was one center at CDC, which was having difficulty.

So W.H.O. has gotten involved in providing the expertise and training, which is a normative role to get them up and running. There’s an African CDC. They’re getting reports from all the countries and with the resources they have, they are trying to do social distancing. They are trying to provide masks to everyone. They have locked down major social gatherings.

And I think they will try to do the best they can with the tools that they have. When you look at the, you know, when I get asked on a call from India or elsewhere in a lower middle income country, we don’t have enough ventilators. I think you have to reflect on the fact is that the best investment in low income countries, when you know in this country, in Boston, between 60 and 80 percent of people on ventilators die. You’re investing in a high-level technology that is not as effective as really education, masks, distancing, closing major social events and trying to enable people to wash their hands where they have water and soap and we’re not providing it.

So I hope African India stay low. I think it’s a bit too early to say. Both of them are beginning to think about relaxing the constraints, and both of them, I think, have to expect an increase in cases. Hopefully not a huge wave.

Q: Just a quick follow up with this. I guess one of the things I’m interested in getting at here and I’m not sure if you would agree or not, is the question of what is the kind of cognitive framework that different states and different parts of the world had at the outset of the epidemic.

I would imagine that if you were from West Africa, if you were from Nigeria or Liberia or somewhere else, when someone tells you that we have an epidemic on the horizon, you’re going to think measles, you’re gonna think Ebola, you’re going to think, you know, any number of diseases. Whereas it seems that the discussion in the United States was more along the lines of, oh, this is going to be a really bad flu season. And it strikes me that perhaps all of the kind of errors in logistics and errors in decision making kind of flow from this primary cognition of how you see the threat.

BARRY BLOOM: So what can I tell you? I can tell you that the first paper predicting the spread of this epidemic was published on January 28 by a former graduate and former fellow of the Harvard School of Public Health, who is the dean of the medical school at Hong Kong University, Gabriel Leung. And from that paper, which was published at that time, I think every epidemiologist in the world that saw that paper published in The New England Journal knew this was going to be an epidemic that the world had not seen before, that it was killing people. And I think at that time, there may have been something like 44, or less than 100 cases, but they already knew there was severe acute respiratory disease that was recognized so that the scientific community really did get galvanized and knew something bad was coming.

I would say the leadership in many countries failed to respond to what the scientists knew was coming. And that’s a tragedy for all. Places like Hong Kong, Singapore knew what was coming, got ahead of it, and they never, up until the recent migrant issue, never had more than a thousand or fifteen hundred cases because they were ahead of the curve and they responded. My impression in Africa is the health people saw what’s happening everywhere in the world, including Italy and including the US, and they know what’s coming and they got moving with the tools that they have as quickly as possible. You know, the simplest answer is in an outbreak of any kind in epidemic, everything expands exponentially. That’s what R0 is telling us, one person spreading it more than one person. And until that gets below one, it explodes exponentially.

There was, there’s just a necessity to have a better connection between people who understand the science and the people who make major decisions of whether to lock up cities and countries. And there has to be an inevitable tension that’s playing out in every one of those countries because the economies are crashing. We knew what was coming scientifically at the Harvard School of Public Health, in Hong Kong, in Oxford, by the end of January. Everything else was a set of decisions made by people other than scientists.

Q: Thank you very much.

MODERATOR: OK. Looks like that is our last question for today. Dr. Bloom, before we go, do you have any last statement you like to make?

BARRY BLOOM: No, but thank you. I enjoy the stress of your wonderful questions. And I believe you guys have, and girls, have an enormously important role in pressing the leadership at evey level to answer questions on who gets whatever treatments and drugs come first. What is America’s role when we do create products that are helpful in this epidemic? What are the plans to share it? How do we get the public? America is the most charitable country in the world. How do we mobilize that spirit to help everyone else, even if there are places here that are not completely protected? Those are major issues and we depend on the press to keep us focused on that. Thank you all very much.

This concludes the May 13 press conference.

Shekhar Saxena, professor of the practice of global mental health in the Department of Global Health and Population (May 12, 2020)

Nancy Krieger, professor of social epidemiology in the Department of Social and Behavioral Sciences, and director of the interdisciplinary concentration on women, gender, and health (May 11, 2020)

Michael Mina, assistant professor of epidemiology (May 8, 2020)