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COVID-19 Vaccines and Herd Immunity

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With coronavirus vaccines now available, what are the timeline and prospects for 'herd immunity' and return to a new normal? Marc Lipsitch, DPhil, of Harvard T.H. Chan School of Public Health returns to JAMA's Q&A series with Paul D. Biddinger, MD, director of Massachusetts General Hospital's Center for Disaster Medicine, to discuss. Recorded December 17, 2020.

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This transcript is auto generated and unedited.

>> Howard Bauchner: Hello and welcome to Conversations with Dr. Bauchner. It is Howard Bauchner, Editor in Chief of JAMA. I'm delighted to be joined by two people. One's been on the show before and is a wonderful guest, Marc Lipsitch. Marc is a Professor of Epidemiology, primary appointment Harvard T.H. Chan School of Public Health where he also has a joint appointment in the Department of Immunology and Infectious Diseases. Marc, welcome, and thanks for coming back again.

>> Marc Lipsitch: Thanks for having me.

>> Howard Bauchner: And I'm also joined by Paul Biddinger. Paul is the Chief Division of Emergency Preparedness Director of MGH Center for Disaster Medicine. We're going to start with Paul, and Paul's going to talk a bit about what his role has been in Massachusetts, and what the last week has been like. And what we think the next couple weeks will be like around vaccine distribution. And then, the three of us are going to talk about when the U.S. could potentially get to herd immunity, which has become an increasingly interesting topic, with now what will likely be the availability of two vaccines by the end of today or tomorrow. So Paul, what is your role with the Commonwealth of Massachusetts?

>> Paul Biddinger: So, with the Commonwealth, I was asked to chair our governor's advisory committee on COVID vaccine rollout for the Commonwealth. I also serve as the Medical Director for Emergency Preparedness for a healthcare system, the Mass General Brigham system. So, simultaneously have been working to rollout our vaccine for a system of 81,000.

>> Howard Bauchner: So, in Massachusetts, as just one example. I saw the map today in the New York Times. Different states got different amounts of vaccine, and they weren't distributed in exactly the same way in each state. So, can you just say, did you know how many vaccines you were going to get? How did they make that decision? And how is Massachusetts doing it?

>> Paul Biddinger: So, I think it's, as you said, different in each state. My understanding is, each state is getting vaccine proportionate to the population of the state. But our advisory group, which Marc also sits on, talked a lot about how to allocate vaccine when it's limited in the initial rollout. We paid attention to the National Academies of Science, Engineering, and Medicine document from October, as well as CDC's advisory committee on immunization practice that endorsed healthcare workers and long-term care residents as the priority groups. Which, by the way, were the same groups that were in the NASAM document as well. The challenge, really, is that based on the way vaccine is rolling out, even within the healthcare workforce, there simply isn't enough vaccine to give to all of the eligible healthcare workers in the first week or so. And so, we know it's going to take several weeks, possibly a couple of months, to get through the healthcare workforce at the same time as we're getting through the long-term care resident community. And so, our group made choices and tried to sub-prioritize really for consistency. I think both for healthcare workers as well as for the public, inconsistency or different approaches among systems makes people concerned and certainly causes, I think, a lack of confidence in the workforce. So, we started with what we called a COVID-facing prioritization, which is looking at healthcare workers who are necessary for response to the surge of COVID that we're currently seeing. It's not to say that we don't believe in our PPE or the safety of the healthcare workforce, so it's not really a risk message. But it's a surge message. We know that for the vast majority of healthcare workers who get infected, that they're exposed in the community setting. And with rising prevalence, there's more COVID out there. So, we need to sustain our healthcare workforce. We asked our hospitals and other healthcare providers to prioritize those workers first. And then, as we move through the healthcare workforce, make other allocation choices.

>> Howard Bauchner: So, were those clinicians, nurses, others working in the emergency room setting? The ICU? Respiratory therapists? Was that, is that the group that ended up being prioritized?

>> Paul Biddinger: So, it is, but with a really important point, at least from the advisory group's opinion, which I strongly share, which is exactly as you said. Emergency departments or intensive care units, community health centers that are diagnosing COVID. But it's actually all of the workers in those care centers. So, it's not just those respiratory therapists, nurses, physicians, but the clerical or environmental services staff. And really, you know, you can't talk about COVID-19 without talking about equity. And that was a strong point that we wanted to make.

>> Howard Bauchner: Marc, was there any debate or discussion about this, or was this decision an easy one?

>> Marc Lipsitch: I think this first one was pretty easy. I think there was very little discussion about that. I think it got, I mean, I've said to a number of people it was one of the most rewarding groups I've ever been a part of in the sense of, you know, it was a respectful and thoughtful and intelligent debate throughout, from a really remarkable group of people. But there was disagreement along the next tiers of people, but I think that first one was pretty well-shared.

>> Howard Bauchner: Just staying with this distribution, Paul. So, I'm making up the numbers, but they'll be easy. Ten thousand doses arrived. You have 25 hospitals in Massachusetts. It's my home state. I know the state well. I'm making up the number. How was the distribution amongst the 25 hospitals decided?

>> Paul Biddinger: So, the state Department of Public Health makes the distribution decision. But generally speaking, it's based on the employee base of the hospitals. There are other factors, though, that go into this. We're in a funny transition period between the emergency-use authorization for Pfizer and not yet Moderna. We think, of course, very very soon, we'll have an NUA for Moderna. The products are actually substantially different in terms of both the size and the storage requirements. So, Pfizer comes out in 975-dose trays and needs ultra-cold storage, where Moderna will come out in 100-dose trays and only needs a refrigerator or freezer. And so, what that results in is, actually, some of the larger systems are able to get vaccines spreaded around to their smaller hospitals that wouldn't necessarily have 975 eligible employees. But it's a phase that favors the acute care hospitals arena, among others, in the medical sector.

>> Howard Bauchner: Not surprisingly, one question has already come in. And I'd like to take the questions, because we're going to switch a bit to herd immunity in a bit. Spouses, significant others of those workers. Are they eligible to be vaccinated?

>> Paul Biddinger: So, our state, and I'm not aware of any other state that's chosen this way, that has not prioritized the family members of healthcare workers. And I think there are important arguments on both sides. Certainly, healthcare workers have been extraordinary in stepping up and caring for patients throughout this pandemic. But we have to recognize that their place at the front of the line includes people behind them with multiple comorbidities, who are older, who have transplant or immunosuppression. And I think we have to do the greatest good with the vaccine that we have.

>> Howard Bauchner: So, the 10,000 doses arrive; they get distributed to the different hospitals. We know that you need 50,000 doses to get that core of healthcare individuals. Are any of those 10,000 doses going to go to individuals in skilled nursing homes who make up 80% of the mortality, even higher in certain states?

>> Paul Biddinger: So, our state program commits to co-incident vaccination of the two groups, of both the long-term care facility patient population and the staff caring for them, as well as the acute medical care community. The logistics probably mean they're about a week apart. So, there will be, there was a little bit of a lag. But that group is moving forward quickly, and as you may know, there's a special federal program to support the long-term care facilities using two commercial pharmacy vendors.

>> Howard Bauchner: Any surprises in the first week?

>> Paul Biddinger: I would say both good and bad surprises. For anyone who has questions about healthcare workers' desire to take the vaccine, I think most systems' experience, very much my own system's experience, is there's overwhelming demand. We have been filling our slots incredibly quickly. This was not a good thing for me or our system, but we actually crashed our system overnight that allows eligible first frontline workers to self-register for vaccination. But I think that's great news. I think, you know, the, I don't want to say surprise, but the negative consequence is, any time you have to phase out allocation, people take it pretty personally. And I think we don't want anyone to feel less valued or to feel disrespected by this process. It really is the simple supply and demand availability and the need to approach it rationally. But I do worry about the feelings that are hurt and the way people feel about an allocation process.

>> Howard Bauchner: It's interesting because I, when I spoke to the NAM, National Academy of Medicine folks and the ASIP folks, they were very careful about the use of the word phase and not tier. And it was really a very purposeful choice. Marc, you alluded to, and then I'll have a question for the two of you before we switch to herd immunity. You alluded to more discussion about the next tier, where I think there's general uniformity, unanimity about healthcare workers, the broad definition of healthcare workers. What's the next tier that became more complicated?

>> Marc Lipsitch: Well, the next tier was more complicated in a sense because, partly because, I mean reflection of the fact that the two authoritative recommendations came down slightly differently. The National Academies prioritized those with co-morbidities and older people, and the ASIP recommendations which have not yet been passed, but which seem to be, maybe, in the pipeline, have a large trunch of so-called essential workers or frontline workers who are the next tier. So, I should also say, Paul didn't get all the way down our, there are a lot of levels of firsts. There is also home health aides. I forget if he mentioned those, and some other smallish groups of people. But the next big group, I think there was support nationally and within our discussion for either choosing frontline workers by some definition as the next tier, or choosing those most at risk of severe outcomes as the next tier. And I think that recognizes a desire to enhance equity, which many of the frontline workers would have been prioritized as people with, who are not only exposed to potential infection, but also came from highly-affected communities. Whereas, the co-morbidity or age-based prioritization would reflect a desire to try to directly save lives as the first priority, and at the same time deal with equity in other ways. And so, that was the meat of the discussion.

>> Howard Bauchner: How did Massachusetts make a final decision? Or has it not yet?

>> Paul Biddinger: Well so, our group made a final recommendation to the governor's office, and the state did release last Wednesday a set of phases. And within the three phases, they selected, there are sub-portions of those phases that go pretty much in the order as Marc just mentioned.

>> Howard Bauchner: Paul, when you see the projections on numbers, and I've spoken to a number of other people who really know much more about vaccine production than I do, said whatever estimates Moderna and Pfizer are giving are good through February 1. After that, they want to, you know, they'll see it when they believe it. That, you know, they're pretty good for four, five, six weeks out. But after that, there could be a lot of hiccups in terms of the supply chain. Getting through healthcare workers and individuals at skilled nursing homes, how long with that take Massachusetts, based upon current projections?

>> Paul Biddinger: Well, based on the projections we have, we think somewhere maybe in February. And I would say those are optimistic projections, but they are, based on the numbers we have, is a plausible way to get through those groups.

>> Howard Bauchner: And so, some of those individuals would have, then, already received their second shot, right? Because both Moderna and Pfizer require a second shot.

>> Paul Biddinger: Yeah, forgive me. So, that's a really important point to clarify. I'm really speaking in terms of first doses. The federal system is set up so that, every time a first dose is allocated, they have guaranteed that a second dose is set aside and will come. So for the most part, when we talk about these numbers, we actually talk about first doses just to avoid confusion. So, I don't think that we'll be done with second doses, certainly, by February. But I think that we should be through the majority of first doses by then.

>> Howard Bauchner: So, the second phase two, Marc, that you had alluded to, doesn't really appear on the radar scope in Massachusetts until sometime in February or March at the earliest? That you're still working through that phase one group of healthcare workers, essential healthcare workers, skilled nursing home, and individuals who support those activities. Is that accurate?

>> Marc Lipsitch: I think that's right. I think the, as I understand it, the Department of Public Health of the state will make a decision as they see what the projections of supply are as to when to sort of turn on the next tap without turning off the previous tap. That's how I understand it.

>> Howard Bauchner: So now, an ethical question for the two of you, and there's quite a few questions coming in. And I'll go back to the questions. Here, so there's been this concern, and in the ASIP documents that I saw, they plotted out the number of people who are willing to accept vaccines. Now, JAMA has not published a single survey, because the response rates are low, the results keep changing, you know, I think ultimately, it's unclear to me what it will be. But some people have said, for example the three presidents should be vaccinated on national tv. Well, actually President Obama would not qualify for, in the first phase. He would qualify in the 100-million plus phase. Other people have suggested that movie stars, athletes, should be vaccinated as examples. Dr. Fauci, Tony, said the other day that he thought President Trump, Vice-President Pence, President-elect Biden, Vice-President-elect Harris should all be vaccinated. Should people jump the queue as examples of being able or willing to accept the vaccine?

>> Paul Biddinger: I think this is incredibly hard, as you said. I mean, I think for the most part, we really need to, as much as possible, hold trust in messengers from the groups as they go forward. I think there are multiple messengers, and I think those who represent different communities or come from different communities should very much be part of the messaging to speak about why they have confidence and what their decision-making process is. I do appreciate that, in our society, there are a number of different people who have different influence. But given the fact that we're prioritizing so much based on limited supply and trying to achieve the goal of saving lives, I think for the most part, celebrity or other really, is hard to endorse. Now I will say that absolutely, our framework and most of the frameworks that are out there, do talk about preservation of essential services in society and critical workers. And I think, at a certain level, leadership certainly does make sense.

>> Howard Bauchner: Yeah, I, Marc, I want you to answer that same question, but I must say, I've been pretty amazed that it seems like the NFL can do 10,000 tests a week and other places can't get testing. I'm not that happy, and I like football. Marc, your sense of messengers being taken out of the queue as important endorsers of being vaccinated?

>> Marc Lipsitch: Yeah, I think, I kind of agree with Paul. But I think, and I think, you know, we tolerate having most people have a lot worse healthcare than presidents and members of Congress all the time, in many ways. And it's not good that that's the case. But for something like this, I think having, you know, a percent of vaccine devoted to people who will set a positive example is a reasonable thing to do. If it became 10% or 20% of the supply, then I would get much more worried. But I think, I think the symbolism might be very valuable.

>> Howard Bauchner: Alright, so lots of questions about actual vaccine supply and cooling. But I want to go on to the issue, Marc, that we touched on with Jay in a previous conversation. Now that vaccines are here, I think people are going to begin to try to project when does a country like the United States, let's focus on the United States, when do we get to herd immunity? What's the magic number? Now, I do think we need to start the conversation with acknowledging we need to make certain assumptions. So, for the purposes of the discussion, let's assume anyone being vaccinated now, let's assume anyone being vaccinated now will have immunity for a year or two. Or about 15% of the U.S. population of 330-million has disease, and will have immunity for the next year or two. Of course, we know that the Moderna and Pfizer vaccines protect against disease. We don't know if they protect against transmission. So, Marc, can you walk us through how you're thinking? What's the magic number? How many people need to be vaccinated to get there?

>> Marc Lipsitch: Sure. And I think the first thing to say is, the short answer is no one knows. Because there are, the math is very easy, and I'll talk about the math in a second. But the right numbers to put into those easy equations are not known. And so that's why it's hard. So, under your assumption that immunity from the vaccine has reasonable longevity, and that immunity from the infection itself also has reasonable longevity, that takes out one of the uncertainties. The simple math is that, if, is that you have to, that herd immunity threshold, the herd immunity threshold, meaning the point at which the vaccine alone can stop transmission in the community without any other kinds of [inaudible]--masks and all the shutdowns that we've experienced. That point comes when each infection leads to less than one new infection, and so the number of infections goes down. And that happens when you vaccinate enough people to slow transmission by essentially putting. People are like control rods in a reaction. The immune people stop the spread because they don't get infected, and they don't pass it on. So, if we have a vaccine that is 95% effective against infection, and that's a big if, which I'll come back to. So, 100% effective. The math is easier that way. And then we can. It's a little bit different. So 100% effective, and each person, when we don't have control measures, is infecting say three other people, which is one of the numbers that's out there. Then, we have to vaccinate two-thirds of the population so that, or immunize two-thirds of the population, so that two of those three infections don't happen. That's the simple math. What's hard about it is the pieces that go into it. And so, the first thing is that reproduction number. That R-zero that we all heard about in February. A lot of the estimates were around three. But some of the estimates were around five, or six, or seven, especially in densely-populated areas. And I think those estimates might be correct. I think it's very, very hard to estimate that number precisely, especially with limited data in a new disease. And I think some of the higher estimates are at least as credible, are at least credible. And so, it might be that we need to immunize say five-sixths of the population or 83%. So, I think that's, the range is probably like two-thirds to 90% have to be immunized. Now, the bigger uncertainty, I think, is that when we have a vaccine that's 95% effective against disease, as you said, we don't know quite how much it slows transmission. Based on the data that exists so far, there's a little bit of data from Moderna and a little bit of data from the AstraZeneca vaccine that suggests that there is an impact on transmission. If you look at people after vaccination, they are less likely to have the virus in their nose when you swab them, even if they're not, even if you take healthy-looking people, asymptomatic people. So, almost certainly there is some effect. How big that effect is is what we don't fully understand. And on one hand, there are other vaccines in the world like the measles vaccine and the flu vaccine that we know really dramatically reduce transmission. And there are other vaccines in the world like the acellular pertussis vaccine and the pneumococcal conjugate vaccine that have a lesser effect on transmission, and a bigger effect on disease. And so, we have precedent for both possibilities. We have a shortage of data. And I think that's why the number might be very hard to predict. But if we have to immunize, say, 80% of the population, and if the vaccine is less than 80% protective against transmission, then that means we have to vaccinate more than everybody. Meaning we can't do it with that alone. Other factors, though, as you say, natural infection will help, will provide some immunity. And I think really, my most important point related to this is that, we don't have to have zero transmission to have a decent society. We have lots of diseases transmitting all the time, some of which kill people. And we don't shut down society for that. If we could vaccinate those people, with very high coverage, those people who are most at risk of severe outcomes, then this disease would be a milder disease. And the people who say we should just let it spread now, which I think is a crazy idea, point out correctly that in many people, this is a mild to moderate illness. And we tolerate mild to moderate illnesses. We don't like them. But we tolerate them. So, if we could really protect the most at risk people, which is maybe 20% or 30% or 40% of the population with a very effective vaccine against disease, which we know we have, then I think that's actually a clearer path to getting somewhere more normal than true herd immunity. But I think every person who gets vaccinated will reduce transmission to a degree we don't know, and will reduce the [inaudible].

>> Howard Bauchner: Oops. Paul?

>> Marc Lipsitch: [Inaudible].

>> Howard Bauchner: Paul, when you hear Marc walk through this. Now, I appreciate you're an emergency room physician, but, and you sit on the same committee that Marc does, advising the governor. So, you know, say you don't, you're not going to focus on children because they generally get mild disease. I'm not suggesting they don't die. But very few die. We have a paper that just went up again today by Steve Wolf that suggested that many more children, up to the age of 24, were dying from other disease far more than COVID-19, even this year. When you hear Marc talk about those estimates, does that help advise the committee when you think about April, May, and June when there'll be more vaccine available, about who the focus should be?

>> Paul Biddinger: It does. I would say there really are a couple of different things we're trying to do as, certainly, as an advisory group. And the first, as we started off with, is to limit the number of people who are at risk of dying. And that is really achieved in two ways. It's epidemiologically identifying those because of their medical situation or their risk of acquiring disease to just limit disease acquisition. But then, there's also to limit disease prevalence. And so, epidemiologically, what can we do to identify who is transmitting disease or where disease is transmitting the most? And so, for example, in our state's advisory group recommendation, we recommended included all congregate care settings along with the long-term care facility. So, prisons or other group settings where you have a large number of people together and the consequences of a single infection are so much greater. So, ultimately, you know, the way we look at it, although my brain hurts when Marc talks about greater than 100% vaccination required for herd immunity.

>> Howard Bauchner: I wrote it down and still can't understand it. You know, when it went above 100%, I had all these plus signs, and I got lost.

>> Paul Biddinger: I guess we each have two shoulders, so maybe there's an answer there. But really, it is a, I think, I obviously strongly agree with what he's saying. I think it's about disease prevalence and it's disease consequence. And so, individuals, I think it's extraordinarily important to try and vaccinate as many people as possible, but do it in a way that limits death, limits risk of severe illness, and helps us get it under, gets the outbreak under control. But ultimately, the more people we get vaccinated, the lower prevalence will be, the less risky any individual interaction is. And especially for those who are at less risk of severe disease. I do think that allows us to start to think about opening up and heading back closer towards normal.

>> Howard Bauchner: Marc, when you, I know you know the data from Massachusetts because you're on this committee and you live in Massachusetts. But when you think about the country, it's a little harder, because I know the states vary. And you've looked at the projected numbers from National Academy of Medicine Advisory Committee on Immunization Practices. When you think about that combination, let's say of healthcare workers, the ring around healthcare workers. Skilled nursing home, the ring around skilled nursing home. Other essential workers. I've said on the show I'm really thankful for the people who work at grocery stores. You know, I still shop once a week at a grocery store. And then, you add in everyone older, 65 or 60. And then, the real contentious issue is, say 20 to 65. What constitutes high risk? Is it hypertension and obesity? When you add those numbers together, what's the range that you come up with in terms of needing to be vaccinated?

>> Marc Lipsitch: Oh, I was hoping you wouldn't ask me to do math that I hadn't done in my head.

>> Howard Bauchner: Oh, I'm sorry, Marc.

>> Marc Lipsitch: It's a lot. I don't think I have the number in front of me or at the top of my head right now. But I think, as Paul said, that being strategic about the priorities means that at least the goal of making our lives more normal, that we can do more or less efficiently. I think the life's, in my mind, what settles the argument for me about where essential workers versus the most severe, people at most risk for severe cases, how you settle that argument to me comes down to the notion that I said earlier. That if we can turn this into a mild illness in the majority of, the vast majority of people by protecting those in whom it would not be mild, then our path to getting back to normal seems much clearer than trying to, thank trying to just immunize every last person, which I think will take a while and has the hesitancy issues and all of that. So, to me the improvement in all of our lives, and indeed the improvement in equity and the return from this disproportionate impact that the pandemic has had on those of lowest income and otherwise disadvantaged comes, I think, from protecting the most vulnerable. And so, to me, I think that's, almost all goals align with that. But that's not everybody's view, and I respect the arguments on the other side. I just, that's how I see it. The one group I would possibly put in a separate category is teachers. And we can talk about that, if you want.

>> Howard Bauchner: Well, I mean, it's been interesting. You know, I've done quite a few shows. We've published quite a bit on it. And I think it's been interesting just over the last couple months, particularly the last couple weeks there's been a real emphasis in trying to have children back in school for in-house education. Unfortunately, it's come at the same time where the numbers have, the number of cases have gotten so large in the U.S. I wish we had had that discussion in August and September when schools opened. You know, the August, September, maybe to Thanksgiving, when people had anticipated it would get worse. Although not this worse. Then maybe back to school in January, February. So, I can understand, I can understand the interest in vaccinating teachers. There's 106, of the 330-million people in the U.S., interestingly enough, about 160-million are under the age of 40; 170-million are above the age of 40. Obviously, this changes and you have to know rates of obesity and hypertension. But it certainly feels like, to me, that the number needed to be vaccinated in this kind of shared herd immunity and less serious disease is going to be north of 100-million people need to be vaccinated. I can't imagine it's going to be much less than that, given the number of risk characteristics that people in their 40s, 50s, and 60s have. But that's a quick back of the envelope calculation. There are some other questions that I'd like to just run through with you, because I like to be responsive to the listeners. And Paul, you may have some answers to these. Will settings that have started on Pfizer, PB vaccines get additional shipments of Moderna, or do they go elsewhere? So, in the estimates that you've been seeing, are you going to begin to get Moderna next week and continue to get Pfizer along with it? Do you have any idea of that yet?

>> Paul Biddinger: We do have some idea. We had thought that those sites like large academic hospitals or large systems might be better suited to Pfizer for reasons I mentioned. Turns out, we probably will get allocations of both Pfizer and Moderna, and pending the EUA and ASIP approval, we expect probably even next week we may have both. As I think everyone understands, each individual has to get a second dose of the same kind. So, if you had Pfizer first, you'll get Pfizer second, et cetera. But for systems, I think we're going to be managing two kinds of vaccine for now. And when others come online, probably more.

>> Howard Bauchner: The Moderna, although it needs to be a chilly environment, it's not quite like the Antarctica that is the Pfizer vaccine. Marc's heard me say before, I thought we should reinvent those old Good Humor trucks, you know, with the little bell. I don't know how cold they get, but I remember when I was young, they'd open up that door and out would come all of the cold air. Can you imagine trying to ship the Moderna vaccine to skilled nursing homes or to environments where minus 80 degrees may not be so easy? Will that be a strategic decision, do you think?

>> Paul Biddinger: So, interestingly, there are elements of the Pfizer vaccine that may work well in the skilled nursing facility program. And by that, I mean there are two large national commercial pharmacy chains taking care of that. They have tremendous cold chain capability. They also are vaccinating at scale. Pfizer is good in the refrigerated environment for five days, and it may be that they can store a large amount at ultracold storage, pull it out of the freezer for refrigeration and move enough vaccine so that they can get through a large number of skilled nursing facilities with the Pfizer. I think it's actually much more the small practices, or community health centers, others that certainly don't have cold chain at minus 80, and really again, would have trouble receiving 975 doses that they have to administer within five days.

>> Howard Bauchner: Marc, I want to return to two, I'll phrase them ethical questions. You addressed one, interestingly, last week in a piece in JAMA. There's been a relatively robust debate among epidemiologists and ethicists about whether individuals who participated in these two trials and received placebo, whether they should now get vaccine. Could you describe your view of this issue?

>> Marc Lipsitch: Sure. With co-authors Annette Rid and Frank Miller, we wrote a piece last week, as you said, in JAMA that makes the argument that the ideal course of action would be to, would be for those people who were on placebo and become eligible in their state program for prioritization, meaning they're ready to get the vaccine given their particular situation, that they should be given the vaccine, they should be unblinded and given the vaccine. Ideally the vaccine within the trial, so the same vaccine they got, or that they were in the trial for and got placebo on. So that the investigators can continue to gather data on them. And that for individuals who are not yet eligible outside the trial, that they should continue to ideally remain blinded, and be followed-up until the point at which they can cross over. We argue that for two reasons. The first being that, the sort of issue that you raised about vaccinating presidents and things, that if we put people in front of the line, that means that the whole line moves back. And we have the line in the order we have it for good reasons of trying to reduce mortality and protect essential workers. And putting placebo recipients from trials in the front doesn't advance that, and actually makes that worse. And the other argument is that we need the scientific data that will come from follow-up of placebo recipients in terms of the longevity of the immune response, the longevity of protection, and further data about which types of people may have different vaccine efficacy from other types of people. So far, it looks pretty even across the types that have been measured. But the data are still quite limited. So, that's the argument we make.

>> Howard Bauchner: Yeah, I appreciate in the back-and-forth with the viewpoint, I did query you about what the consent form said. Because I thought that always is important; people do consent to be in trials, and you indicated that, in fact, the consent forms did not indicate that if they had received placebo, they ultimately would receive active vaccine. Paul, has the, did that come in front of the governor's committee or is that something you didn't consider?

>> Paul Biddinger: Well, I would say it's not within our purview, but it doesn't mean we didn't talk about it. In general, I think the same principles held true. We didn't discuss it in detail because, again, I think it's not something that we have jurisdiction over. But I do support what Marc's saying.

>> Howard Bauchner: Has there been any discussion, as I said, you, it's still unclear how quickly you're going to get vaccines. I have a couple additional questions. Let's say in a few weeks, Moderna and Pfizer announce that, actually, they're not going to be able to provide as much, as many doses as they had hoped. It's a little unclear. The numbers get very small if you look at the reports that the FDA put out. I always worry because people focus on the point estimate and not the confidence interval. The confidence interval for individuals older than 65, particularly for the Pfizer vaccine, goes as low as 44%. Now again, I know the numbers are thin, so you can't be certain. Has there been any discussion of not giving people a second dose, but using that second dose to vaccinate an additional 10,000 people?

>> Paul Biddinger: Marc, do you want to start or do you want me to?

>> Marc Lipsitch: I mean, it's been discussed and in a previous, before COVID was even a thing, we did some modeling work for this question on yellow fever vaccines for using smaller doses rather than fewer. It is an idea that's out there. I can't imagine it happening, given the number of changes that would have to happen and the regulatory issues. But I've been proven wrong before, so.

>> Howard Bauchner: Paul, comment on it?

>> Paul Biddinger: I would say so. I think, you know, all conversations are good to have. But I worry that right now, the messaging is that people might not need the second dose. I think people are actually pretty aware that the Pfizer data suggests that maybe, you know, you get 50% protection a week after. And what I worry about is that we have a number of partially vaccinated or partially protected people. And to Marc's previous point about herd immunity, what we want to do is maximize the effectiveness of the immunization. And so, I think the full message right now is get fully immunized. If we are faced with some very, very tough choices, as we have been repeatedly through this pandemic, it's good for us to think about it. But right now, I pretty strongly want people to understand a second dose is really what it takes to be fully vaccinated.

>> Howard Bauchner: I just want to finish up with a couple other questions that have come through. Any sense, after Moderna and Pfizer, what's next?

>> Paul Biddinger: Well, we do know that candidates from Johnson and Johnson, from AstraZeneca, from others are in the pipeline. There obviously has been different public commentary on how they're doing and where they are. You know, obviously what we're all hopeful for is more vaccines for more supply, for the reasons we were just talking about. I think it's going to be inevitable that people will compare effectiveness among the vaccines, and I think that's actually somewhat unfortunate. I think more vaccine is what we need. And even other vaccines that may not be at the 94%, 95% effectiveness level, as long as we have confidence in their safety, I absolutely am looking forward to rolling them out.

>> Howard Bauchner: Marc, any additional information cross your desk about when other companies will be applying for an EUA?

>> Marc Lipsitch: No, no. That hasn't crossed my desk. I would just say also that there is a big global supply issue that's being overshadowed this week because a couple of wealthy countries have moved ahead. But I think that the ability to supply billions of people around the globe is going to require a number of vaccines from a number of companies. And so, I think as a global proposition, this is even more important in terms of making sure that there's access. And I think that will be delayed, but will begin to speed up, especially if the U.S., under its new administration, decides to join the international efforts that have been ongoing for almost a year without our help.

>> Howard Bauchner: Yeah, no, it was one of the next questions I was going to ask about, distribution of vaccines to low- and middle-income countries. And I think everyone recognizes that could be a substantial lift for both of the two current vaccines that are likely to be approved in the U.S., Moderna and Pfizer. It's not beyond imagination that they could be used in low- and middle-income countries; but supply chain will be even more complicated there than it is in the United States, Canada, and the U.K. It seems like those three countries have done a very good job about buying up as much vaccine as possible. So, the current recommendation is that you vaccinate an individual even if they previously had disease or they think they've had disease. I believe that's the current recommendation from the advisory committee. But there are people who are developing symptoms that appear to be related to having had disease. Any discussion about whether or not those individuals should be vaccinated? So-called long haulers.

>> Paul Biddinger: Yeah, so I mean, I think right now the recommendation coming from ASIP is everyone who has had infection in the past, as long as they've recovered, should be vaccinated. There's been some discussion about waiting three months, just because the thought that within three months, your chance of reinfection is exceedingly low. So, it's really more kind of a queueing argument than a medical contraindication argument. We clearly just haven't had enough time to know about the durability of immunization and protection from these vaccines. But I definitely support people getting the vaccination as soon as they are able to in their priority, or in their appropriate phase, because I think there's a decent chance of more durable immunity.

>> Howard Bauchner: Marc, I'd like to finish with you. You've been so kind in giving me much of your time writing for us. You know, I think the scientific achievement of the vaccines is extraordinary. And as I did last week, I want to compliment the scientists at Pfizer and at Moderna. It is a remarkable achievement. I think there's been other issues with some of the clinical advances that have been slower to come to fruition. But the scientific heft of the vaccine development is, I think everyone acknowledges, has been extraordinary. What does the next two or three months look like, Marc?

>> Marc Lipsitch: Well, I want to just add to your point and totally endorse the kudos to the vaccine companies. But also, to the success of scientific planning that began, really during Ebola when it was recognized by a number of scientific leaders that we would need vaccines for future outbreaks and pandemics. A minor journal, regional journal of medicine that competes with JAMA published an editorial by three of those leaders suggesting that such an activity be undertaken. And that was the origin of CEPI, the Coalition for Epidemic Preparedness Innovations, which then invested heavily in vaccine platforms and including the MRNA platform and including in coronavirus vaccines. And it's unquestionably true that much of the speed that was possible came from those investments, not just by CEPI but also by others at NIH and elsewhere, in pandemic preparedness. So, I think next time people are accusing people like me of crying wolf and saying we have to be prepared, or like Paul, this was a case where it really has paid off dramatically for the whole world. And it was advanced preparation for several years.

>> Howard Bauchner: Tony had written a viewpoint for us three years ago about preparedness in the face of a pandemic. And he talked about all of the new platforms: viral DNA and MRA. And once again, it was prescient. I mean, this was three years ago. He thought we could get there in a year-and-a-half or two years. I think, when I've spoken to him, he's amazed that it's nine months. But the next couple months, Marc. The numbers the last couple days are so discouraging. 250,000 cases. Over 3,000 deaths. But I'm, you know, what's Christmas to January to February to March like?

>> Marc Lipsitch: Yeah, I mean, I think we have, as it's been the case for a year now almost, we have a lot of infected people and a lot of susceptible people, and they're mixing. And I keep hearing about person after person whose got complicated travel plans for Christmas time. The disease is going to continue to increase in prevalence in many parts of the country and the world. And that's going to lead to continued growing demands on health care and continued mortality, increased mortality. And the vaccine will begin to take a bite out of that in the, you know, in February and March maybe. But not in January, because it will be too soon. And we really have a lot of work to do as a country to try to minimize transmission in the coming months. We have this light at the end of the tunnel, but I think we've got, it's pretty far away still in terms of being able to return to our fun and frolic. And unfortunately, the long, dark winter metaphor that the New York Times used I think is right. But it is, I think, a little easier to bear knowing that there is a potential end in sight.

>> Howard Bauchner: Yeah, I do think, I do think Vivek Murthy, the new Surgeon General, Rochelle Walensky, the new head of the CDC, and Tony will once again be an advisor to his seventh president. And I think the president and vice-president will speak with the single voice that social distancing, masking, handwashing are mandatory for the next three, four, five, six months, 12 months. But just because the vaccine is now being distributed doesn't mean those key elements of public health prevention are any less necessary. Paul, your sense of what the next couple months look like?

>> Paul Biddinger: Yeah, boy do I wish I was more optimistic, but I think sometimes Marc and I race each other for pessimism. I'm very, very concerned about what January is going to look like. You know, we saw the impact of Thanksgiving on cases. And we saw really clearly in the epidemic, heard what it's doing, on top of what was already an uncontrolled spread. I think that the continued mixing and travel that we're about to see over the end of this month really is going to make things worse. And you know, I know everyone is fatigued with all of these interventions. That's playing a role. Maybe people are excessively optimistic about how quickly a vaccine will help us change the direction of this, but you know, for the next two, three, four months, it's all still about following the same recommendations that we've had all the way along. That we know work. We know that that guidance is useful in getting control of this pandemic. And I think we just need to continue to beat the drum that it's so, so important. There is preventable death that is happening right now as a result of our not following these restrictions. And it's just what we need to do; to hunker down just a little longer.

>> Howard Bauchner: We published a paper by Steve Wolf with a number of other papers in October that projected 400,000 excess deaths. We were a little nervous because when we put numbers in print in JAMA, they tend often to captivate people's imagination. In hindsight, that 400,000 in terms of excess deaths is likely to be north of 500,000 deaths this year. And the one thing the U.S. and the CDC do well is count deaths. And we'll know by February how many excess deaths. So, deaths attributable directly to COVID-19 and the additional deaths attributable to the pandemic that have occurred. But it could very well be above 500,000, which would exceed the deaths from World War II. Howard Bauchner, Editor in Chief of JAMA. This has been Conversations with Dr. Bauchner. I've been joined by Paul Biddinger, who's joined me for the first time, Chief Division of Emergency Preparedness, Director of Mass General Center for Disaster Medicine and professor of medicine at Harvard Medical School. And on the governor's advisory committee around this pandemic. And Marc Lipsitch who's joined me for the third or fourth time, professor of epidemiology, Harvard T.H. Chan School of Medicine. And Marc, I promise you in the name of Michael Osterholm, I'll have you back in a month. So, if any of those estimates are really off, you can correct them. Michael told me he wanted to come on every two weeks so he could correct what he had said two weeks previously.

>> Marc Lipsitch: Thank you.

>> Howard Bauchner: Thank you. I wish both of you season's greetings, happy holidays if appropriate and of course, stay healthy, stay safe, and keep your meetings small. Bye bye.

>> Marc Lipsitch: Bye bye.

AMA CME Accreditation Information

Credit Designation Statement: The American Medical Association designates this Enduring Material activity for a maximum of 0.75  AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to:

  • 0.75 Medical Knowledge MOC points in the American Board of Internal Medicine's (ABIM) Maintenance of Certification (MOC) program;;
  • 0.75 Self-Assessment points in the American Board of Otolaryngology – Head and Neck Surgery’s (ABOHNS) Continuing Certification program;
  • 0.75 MOC points in the American Board of Pediatrics’ (ABP) Maintenance of Certification (MOC) program;
  • 0.75 Lifelong Learning points in the American Board of Pathology’s (ABPath) Continuing Certification program; and
  • 0.75 CME points in the American Board of Surgery’s (ABS) Continuing Certification program

It is the CME activity provider's responsibility to submit participant completion information to ACCME for the purpose of granting MOC credit.


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