The United States is at a new inflection point in the COVID-19 pandemic. Public health experts are beginning to say that the country may not reach so-called 鈥渧accine-mediated herd immunity.鈥�
鈥淚 always say there鈥檚 this elusive, somewhat mystical terminology of 鈥榟erd immunity鈥� and 鈥榟erd immunity threshold,鈥� 鈥� Dr. Anthony Fauci says. 鈥淵ou know, that is when you get such a blanketed protection over the community. And we don鈥檛 know what that number is. I mean, it鈥檚 an estimate. I have estimated for months now it鈥檚 somewhere between 70 and 85 percent.鈥�
While Fauci says he鈥檚 always called herd immunity somewhat elusive, it鈥檚 only very recently that he, and other public health leaders, have ventured to say clearly we may never reach that threshold 鈥� no matter what it is.
And why? About a third of American adults are fully vaccinated. More than half have had at least one shot. But new daily vaccinations are dropping, and polls find that about 30 percent of the US population is still reluctant to be vaccinated.
That鈥檚 leading some public health experts, , to say that they don鈥檛 expect much more than 50 percent of Americans to eventually be fully vaccinated.
In this special web exclusive, Dr. Anthony Fauci joins Meghna Chakrabarti to discuss herd immunity, potential measures to help guide public health decisions and more.
In this web exclusive 鈥� we hear from:
, director of the National Institute of Allergy and Infectious Diseases. ()
Full Transcript:
Anthony Fauci: Well, [the vaccination efforts] continue to do really, really very well. If you look at the fact that we now have over 200 million doses, about 220 million doses were given during the first 100 days of the Biden administration. So, things continue to look good. We鈥檝e had a slight dip. We were averaging between 3 and 4 million doses a day. We鈥檙e now at about 2.9. So that鈥檚 close to 3 million per day. It鈥檚 expected as the cohort of people that you鈥檙e vaccinating becomes less and less because you vaccinated more and more, that the number of vaccinations per day are going to diminish a bit. But we鈥檙e going to continue to really push and reach out to people to get trusted messengers, to convince people, people who they trust as to why it鈥檚 important for your own health, the health of your family and that of the community to get vaccinated. So bottom line is the vaccine rollout program is going really very, very well.
Meghna Chakrabarti: You know, it is very reasonable, as you said, that in this phase of a mass vaccination campaign that the daily rate might slow down. But what I鈥檓 really interested in our overall goals. Right? Because historically 鈥� and when I say that, I mean, over the past several months 鈥� I鈥檝e heard you say repeatedly that in order to achieve that so-called a vaccine-mediated herd immunity in this country, we鈥檙e going to be needing to aim to around the 80 percent mark, if not higher, of adults being fully vaccinated. At this point in time, Do you still think we can reach that number?
Fauci: Yeah. You know, Meghna, I want to clarify one thing so that people don鈥檛 get confused. And I always say there鈥檚 this elusive, somewhat mystical terminology of 鈥渉erd immunity鈥� and 鈥渉erd immunity threshold.鈥� You know, that is when you get such a blanketed protection over the community. And we don鈥檛 know what that number is, Meghna. I mean, it鈥檚 an estimate. I have estimated for months now it鈥檚 somewhere between 70 and 85 percent. But we really don鈥檛 know that because that鈥檚 influenced by so many factors: the durability of immunity for people who鈥檝e previously been infected, the appearance of variance and things like that. So I prefer rather than concentrating on this somewhat nondescript concept that we still don鈥檛 know what that number is, is to say, 鈥淟et鈥檚 get as many people vaccinated as quickly as you possibly can.鈥�
And even if you don鈥檛 reach whatever percentage that number is going to be, you鈥檙e still going to have a profound impact on the number of infections in society. So people sometimes think that you鈥檙e not going to have a real dramatic drop in daily infections until you reach this very elusive terminology of vaccine immunity or herd immunity threshold. You can start to see really important results as you get closer and closer to it. So every day that goes by that you get an additional 3 million people vaccinated, you鈥檙e going to start seeing getting closer and closer to start seeing a significant diminution in the number of cases.
For example, for several, several weeks, we had a seven-day average of about 60,000 infections per day. It is gone down now over 20 percent or more, down to somewhere in the 50,000 per day. And as we get more and more people vaccinated, it鈥檚 going to go down to 40 and then 30 and then 20. So we don鈥檛 know what this number is of what percent people vaccinated is going to be. But we do know something for sure, Meghna. And that is: the more people you get vaccinated, the closer and closer you get to getting control in the community, which is the reason why we so strongly recommend and plead with people to get vaccinated, not only for their own protection, but for that of their family and for the community.
Chakrabarti: I鈥檓 really intrigued by what you鈥檙e saying. And on this show, what we鈥檝e been trying to do for the past year is kind of help people navigate the uncertainty that COVID has thrust us all into. And what I found is that people want tools on how to decide how to live, what to do, what鈥檚 safe, what鈥檚 not safe. And one of the tools that鈥檚 helpful is to kind of have a goal to aim for, which is why people wonder about what threshold do we need to reach for herd immunity. And it鈥檚 interesting to hear you say that maybe that number isn鈥檛 so important anymore. That鈥檚 coming at a time where I鈥檓 hearing other public health experts say they鈥檙e starting to think in terms of the percentage of Americans who will be fully vaccinated. We may not get over 50 percent. So, let me ask you. I still think people want a goal, right?
Fauci: Right.
Chakrabarti: They want to know sort of how to live their lives so that we as a nation can get to a better place. So what I鈥檓 curious about is 鈥� let鈥檚 just theorize for a second, say we don鈥檛 get much beyond that 50 percent fully vaccinated. What metrics are you using? What measure are you using to say: When we hit this particular point 鈥� let鈥檚 say in deaths per day or new infections per day 鈥� that we can consider COVID no longer pandemic, but a manageable endemic disease like the flu?
Fauci: Yeah, you know, again, it depends on what you mean by the infection and what it causes. Let me give you an example: It could be that when a certain percentage of people get vaccinated, the number of hospitalizations will go down. So it may be a situation where you get people infected to get mild symptoms, but very few people get hospitalized when you have a certain percentage of people vaccinated. So you could say that that could be a certain number of hospitalizations per 100,000 population. And then you could do modeling to figure out what that is or the number of positive test case positivity. Those are the kind of things that you look at.
You know, people will give you estimates because they don鈥檛 know what the dynamics of the outbreak will be because this is such a new experience with this particular virus, particularly given the fact that we have variants that go around that may be variably protected by the vaccine. So I know people would like to know a metric. You know, the best metric is 鈥渒eep going.鈥� And when the when the numbers of infections get down to such a low level, that could be, let鈥檚 say, well, south of 10,000 per day, maybe even 5,000 per day. I mean, now, I say that and all of a sudden it becomes a sound bite. I don鈥檛 want it to be that because quite frankly, Meghna, we don鈥檛 know what that number鈥檚 going to be when you can get a real good approximation to normality. So what really people want to know is less of what that number is. [It鈥檚] 鈥淲hen can I start getting my life back?鈥�
Chakrabarti: Right.
Fauci: When can I start going out to dinner, going to the movies, going to a ball game, making sure the kids are safely in school? And that number will be when that level of infection is really very low. But you won鈥檛 know what that is. I mean, it should be, you know, in the few thousand as opposed to 30, 40, 50, 60 thousand.
Chakrabarti: Yeah. Because, you know, I get it. But like policymakers, they鈥檙e looking at those models to figure out when they鈥檙e going to feel comfortable with those numbers getting low enough so that, like you said, people can get their lives back to normal. On a normal flu year, for example, which this past year was not 鈥� but a normal flu year, let鈥檚 say, deaths per day across this country, there are 100 deaths per day. And we鈥檝e had that rolling along for years and years and years and no interruption of the vast majority of people鈥檚 daily lives. Is that the kind of thing we ought to be aiming for regarding COVID?
Fauci: Well, you know, once we go through, I can tell you that鈥檚 what鈥檚 going to happen. We have decades and decades and decades of experience with influenza. We don鈥檛 know what it鈥檚 going to look like when you get down to 500, 400, 300, 200, 100 deaths per day. We don鈥檛 know what the impact is going to be on society, about what they鈥檙e willing to do, because you鈥檙e dealing with very different infections, very different dynamics of the infections. So I think what we have to do is 鈥� that鈥檚 why I keep saying: Let鈥檚 just push to get as many people vaccinated as possible and find out how low that is going to get us, how low in hospitalizations, how low in deaths and how low in documented, clinically recognizable infections. That鈥檚 what we need to know.
And when we know that, and we鈥檙e dealing with this virus, if we go another year or so with this. And I鈥檓 not talking about a year of a pandemic. I鈥檓 talking about we鈥檙e not going to eradicate this year. And it鈥檚 very unlikely we鈥檙e going to eliminate it. But what I do know we鈥檙e going to do, we鈥檙e going to be able to control it. And the situation is: at what level of control is society going to be able to get back to as close to normal as you possibly can?
Chakrabarti: So, Dr. Fauci, I have one more quick question here. First of all, full disclosure: My master鈥檚 degree is in environmental science and risk management, so these risk questions are 鈥� I can鈥檛 help but to ask them. I really can鈥檛. Because especially like that鈥檚 the interface between sort of how to manage scientific and public health uncertainty with policy making decisions. Right? And I know you鈥檝e been through the wringer over the past year, but I hear you very strenuously trying to not answer a question here. So let me rephrase it. Let me rephrase it. You鈥檙e advising the Biden administration and certainly the Biden administration 鈥� I know they鈥檙e thinking about these questions because they鈥檝e got to make announcements. They鈥檝e got to communicate to the people, the CDC, et cetera. What are you advising them on what they ought to be aiming for regarding 鈥� how we鈥檙e going to know when COVID is under control?
Fauci: Well, you know, that鈥檚 right. And I鈥檓 not 鈥� Meghna, I鈥檓 smiling because you鈥檙e saying that I鈥檓 trying very hard not to answer your question. I am answering your question. We don鈥檛 know what that number is. We don鈥檛 know what a number will be, when you鈥檙e going to have so control that people are going to feel comfortable about going out. I mean, we could give you a real number when there鈥檚 no infection, when you鈥檝e actually controlled it so that they鈥檙e essentially so few infections, you could barely count them.
But we don鈥檛 know if that鈥檚 going to be the case with the dynamics. So it isn鈥檛 as if we鈥檙e avoiding your question. We don鈥檛 know the precise answer to that, because that gets to why I keep saying this elusive terminology of herd immunity. So, you know, herd immunity is when you really get the true herd immunity. We have herd immunity right now, Meghna, with measles. OK? So we have such a blanket of protection in our society that essentially nobody gets measles except when they travel from outside the country into the country. And you have such a high level of protection of people that in fact there鈥檚 no infection.
Have we eradicated measles? No, we haven鈥檛. Have we eliminated it for the most part in this country? The answer is yes. So I would like to see that happen with COVID-19. But what we don鈥檛 know is [at] what percentage of the population are we going to get to the point where you don鈥檛 really have any COVID-19? And if you do, is it going to be like influenza where We鈥檒l say, OK, we can live with this particular number. And that鈥檚 why I鈥檓 saying right now we don鈥檛 know what that particular number is. We can go back and just pick a number and say we鈥檙e going to stick by that number and then everyone will say, OK, we have a goal. Let鈥檚 go by that.
Chakrabarti: OK, so this is really important, Dr. Fauci, because, again, it keeps getting back to people desperately wanting to know, as you said, when can they get back to their regular lives? So we don鈥檛 know what that number is regarding COVID.
Fauci: Right.
Chakrabarti: But we鈥檙e going to have to make a 鈥� that鈥檚 actually a subjective decision, right?
Fauci: Right.
Chakrabarti: I mean, that鈥檚 kind of what you鈥檙e saying. So let me let鈥檚 just, like, change the lens on the focus on this for just a second here. What are the questions or the information or the data that public health officials, the Biden administration, et cetera, would want to know in order to help decide what that number could be?
Fauci: You know, the classic one that you鈥檙e referring to, Meghna, is the issue. And getting back to the terminology I like to stay away from, because this also is an elusive terminology, is the R0. 鈥� So when it gets less than one, and it stays at less than one, you鈥檙e going to see this essentially disappear from society. So I could tell you when the R0 goes less than one and it keeps going down, that鈥檚 where we鈥檙e going to be. But, you know, that, again, is an elusive term because the R0 really is influenced by a lot of things. It鈥檚 not inherent to the virus itself. It鈥檚 influenced by things like, you know, crowding in the situation that people are in.
Chakrabarti: So then folks are listening right now, what would you tell them in terms of how to go about their lives at this moment? Obviously, you鈥檙e going to say get vaccinated, for sure. But I think, you know, people just need to know what should they be doing now and how long could this go on?
Fauci: You know, it will change, and it will change again, depending upon the level of the dynamics of the virus in society. So right now, what you鈥檝e seen and will continue to see is a gradual liberalization of what one can do, depending upon the level of virus in society and the number of people who are vaccinated, which will definitely influence that level of infection in the society.
For example, right now, when we were having 60,000 infections per day, the CDC, which is the larger group of epidemiologists that make these models and talk about the kinds of things you鈥檙e asking about, felt comfortable that people who were masked can now feel much safer traveling. They can be with other people who are vaccinated in the home without the masks, having physical contact. They then came out a couple of days ago as the levels started going down, and we are getting more and more people vaccinated that they could eat outdoors without a mask, that they could be doing things with outdoor activities without a mask.
And as the weeks go by and you get more and more people vaccinated and less and less infections, there鈥檚 going to be more liberalization about who can 鈥� how many people can be in a ballpark to watch a game. What about indoor dining? What about going back to the workplace? You鈥檙e going to start to see gradual liberalization of those guidelines associated with the continued diminution of the number of cases which will be profoundly influenced by the number of people who get vaccinated. And that鈥檚 why I say 鈥� and you think I鈥檓 being evasive; I鈥檓 not 鈥� 鈥淟et鈥檚 all get vaccinated,鈥� and you鈥檒l know it when you see it.
Chakrabarti: I suppose it鈥檚 not evasiveness, it鈥檚 the understandable uncertainty that people don鈥檛 know how to deal with. Last question. How are you doing?
Fauci: I鈥檓 doing fine. You鈥檙e wearing me down, Meghna.
Chakrabarti: Not intended here. OK, I think I hear your people saying get off the line. So let me just give you a proper thank you here. Well, Dr. Anthony Fauci, thank you so much for joining us today.
Fauci: Good to be with you. Thank you for having me.
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