Covid-19: Public Health And Scientific Challenges with Anthony Fauci MD Nov. 18, 2020

advertisement
>> Marcia Day Childress: Welcome to the University of Virginia School of Medicine's Medical Center Hour. I'm Marcia Day Childress from UVA's Center for Health Humanities and Ethics. We're so very glad you've joined this forum in medicine, healthcare and society. Some Zoom webinar housekeeping.

Slides at the end of this program provide a resource list, information about continuing education credit for clinicians and a link to our center's website where you'll f ind our speakers' biography. The slides give a link to Medical Center Hour YouTube channel. Today's program is being recorded and closed captioned and will be posted to YouTube within days.

Today we'll handle questions using Zoom's online Q&A function. Write your questions there, brief and to the point please and we'll draw from them for our speakers' consideration after his presentation. This Medical Center Hour joins with Medicine Grand Rounds for the annual Hayden-Farr lecture in which an esteemed physician scientists addresses medically and socially significant matters in virology and epidemiology.

The lectureship honors UVA virologist and professor emeritus Fredrick Hayden and remembers our late hospital epidemiologist Barry Farr. We thank you the Department of Medicine for being our partner. Our 2020 Hayden-Farr lecturer disclosed no conflicts of interest. Here to introduce and welcome today's Hayden-Farr lecturer, Dr.

Anthony Fauci is Dr. David Wilkes, Dean of the UVA School of Medicine. Dr. Wilkes? >> Dr. David Wilkes: Thank you, Marcia. To begin I would like to thank Dr. Fred Hayden and Marcia Childress for extending the invitation to have Anthony Fauci and thank you, Dr. Fauci for accepting our invitation.

Dr. Fauci is the director of National Institute of allergy and infectious diseases at the National Institute of health and he's held that position since 1984 where he oversees extensive research to infectious and mediated diseases. As a long time chief of the Laboratory of Immunoregulation Dr.

Fauci has made many contributions in basic and clinical research, his publications and presentations number in the thousands and he's one of the world's most cited bio-medical scientists. Recognition for his outstanding service includes the U.S. presidential Medal of freedom awarded by President George W.

Bush and the public square, Dr. Fauci is lauded for his work in epidemic infectious disease, two global pandemics bookend his career. In the 1980s it was HIV/AIDS and now C OVID-19. He was one of the emergency plans for aged relief, known as PEPFAR, a program launched in 2003 under president George W.

Bush that saved millions of lives throughout the developing world. In 2020, Dr. Fauci leads NIH's Coronavirus research effort and is a member of the White House Coronavirus task force. He's become the scientific and l community's leading spokesperson on the COVID-19 pandemic and his management including vaccine development and the critical importance of non-pharmaceutical interventions such as masking and social understandings and Dr.

Fauci is a master communicator on matters of concern to medicine, healthcare and society. I would like to mention on a personal note I was very fortunate to serve on the NIAID national council in 2006 to 2010 when I got a chance to watch Dr. Fauci in action in person. He is the role model of the physict administrator, educator and so much more.

We're grateful and proud to welcome him at the University of Virginia School of Medicine 2020 Hayden-Farr lecturer, Dr. Fauci? >> DR. FAUCI: Thank you very much Dr. Wilkes and thank you to the University of Virginia for inviting me to give this Hayden-Farr lecture. It's a great pleasure and an honor to be here with you today.

As you can see from this first slide I've chosen as the title, the public health and scientific challenges of COVID- Now I want to start off by showing the cover of this JAMA view poi which my colleagues and I wrote in January of 2020 literally a couple of weeks after the identification of the novel Coronavirus and I entitled it Coronavirus infections more than just the common cold and I did not at all mean to be factitious by this title but I wanted to bring out to the readers of the view point the fact that for decades and decades we've had experience with Coronaviruses so with this was just not something that was totally new to us.

This is a Coronavirus phylogenetic tree. The human Coronaviruses are in red letters and as you can see that four of them that are shaded in yellow are the four human Coronaviruses that are responsible for anywhere from 15 to 30% of the common colds that we experience repetitively each year usually during the winter months.

Now that was essentially considered really not particularly important series of infections until we got into 2002 and 2012 with the first and then the second pandemic Coronavirus with Sars, the severe acute respiratory syndrome and MERS. Let's look at that. Some of you might recall that in 2002 would emerge from the province of China was a disease that was referred to as severe acute respiratory syndrome, which came from a bat to an intermediate host, the cat and then ultimately to humans leading to about 8,000 infections and then about 780 or so, close to 800 deaths.

This was the first of the recognizable Coronavirus pandemics. Ten years later in 2012, another pandemic Coronavirus called Middle East respiratory syndrome, this was a disease that passed from bats to camels to humans. It did not have the capability of spreading rapidly and still smolders somewhat in the Middle East, I might add that Sars was contained completely through public health measures of identification, isolation, contact tracing and quarantine.

It had a moderately efficient capability of spreading from human to human but good public health measures essentially eliminated it. Now let's get to the present time. The third pandemic Coronavirus recognized, excuse me, as an unusual pneumonia emanating out of wet market in the Wuhan province in China.

Literally within the period of a couple of weeks in early January, the Chinese identified this as another strain of Coronavirus that was put up on a public database. As you see here, it is from a phylogenetic standpoint proximal to the original Sars hence the nomenclature was changed and the new novel Coronavirus became Sars cov2.

When you look at the nomenclature all in one, the disease caused by this novel Coronavirus is called COVID-19 for Coronavirus disease 2019 based on its recognition in December of 2019 and as mentioned a moment ago the virus itself is referred to as Sars COV2. Where are we with that now? This virus as we all sadly knows that exploded upon our planet to be the worst outbreak of a respiratory infection in 102 years since the 1918 Spanish flu.

Currently, as of yesterday, there were 56 million cases and over 1.3 million deaths globally. Unfortunately, for us in the United States, we are the country that was hit the hardest and continues to be hit the hardest by this outbreak with more than 11 million cases and now over 245,000 deaths.

The current distribution and deaths per -- cases per hundred thousand, excuse me, is shown here on thiy dark being the worst and light being the lightest. Now if you look at the risk levels in the United States by county, you can see where we are now in the hottest levels. We are in the processes I'll get in a moment of another resurgence as we enter into the much colder months of the late fall and early winter and people go indoors much more than outdoors and they're gatherings with friends and with families.

I want to point something out that I think is worth noting is the difference in dynamics, response and baseline between the United States and the European Union. If you look at the blue, you recall Europe, particularly northern Italy, had their peak a week or two before ours, in fact, New York City Metropolitan area was seated not from China, but from Europe, particularly northern Italy.

When they reached their peak with the blue line, they came down to a baseline that was quite low. In contrast, in the United States with the burst of cases dominated by the New York City Metropolitan area, we never got down to a real baseline because as things got under control in New York City we had outbreaks in various parts of the country, keeping the baseline at about 40,000 until we tried to so-called re-open the country and re-open the economy.

As you can see from June to August, we had a surge up to about 70,000 cases per day, which after a while leveled off and hung around 40,000 a day. A very bad position to be in when you enter into the vulnerable position of the winter months and people going indoors and as you can see right now we, and European Union is right there with us, in a major surge of cases where we are now breaking all current records that we've had before with over 1,000 deaths per day, over 100,000 the last was about 150,000 cases in a day.

I testified before the Congress a couple of months ago when we were at 40,000 and said that if we did not do something different and contain this, it is conceivable we would get to 100,000 cases a day. I was severely criticized by some members of the Congress for being hyperbolic and now we've been as high as 180,000 cases a day with hospitalizations over 70,000 and the numbers totality of cases I showed you a little bit ago.

So why was there this difference of baselines? If you look in the United States, and you l ook at a parameter of movement, namely, how much do you actually shut down? Well in the United States although we were talking about shutting down following the New York City outbreak, in fact, the percentage of people who visited parks and outdoor spaces that decreased looking at Italy and Spain as representative of the European Union, we did not shut down nearly as much as they did.

We in the dark line, Italy and Spain in the lighter lines. If you look at visit or presence in workplaces and namely how many people actually did not go to the workplace? Again look at the shut down in Spain and Italy versus the United States and then if you look at grocery and pharmacy store visits.

Again, what you can see that Spain and Italy shut down certainly much more than we did. So that's a glimpse of the epidemiology. Let's take a look at the virology. So what we see here is that something I told you and alluded to a moment ago. It's a beta Coronavirus, an RNA virus so you would expect it to mutate somewhat.

There's four structural proteins the most prominent and important of which is the spike protein who's receptor binding domain is shown in the green there, binding to the ace receptor a when is the cellular receptor which is distributed widely in the upper and lower airway, the GI tract and other organ systems, including the heart.

This structure has been now determined in its pre-fusion form by barnie Graham and Jason McLillan and others at the NIH and is actually the now prototype that has been used in some of the vaccines that I'll talk about in just a little bit. What about transmission? Now obviously this is a respiratory-borne virus transmitted by the classic respiratory droplets which tend to drop to the ground within a few feet, hence the six foot distance discussion that we have, however, recently it has been clear that a certain proportion of the transmission do occur for what we refer to as aerosol namely particles containing virus that are light enough that they stay suspended over time and through various distances for various periods of part-time.

The virus can be found on contaminated surfaces, the role in transmission is unclear and the virus is found in multiple body fluids but here again the role in transmission is unclear and likely not significant. If you look at the risk of transmission, we know it varies by the type and the duration of exposure as well as the viral load in the upper respiratory tract.

Transmission are common among household contacts and in congregate settings where PPE is not used. There's reasonably good protection if healthcare workers have adequate and appropriate PPE. But we've seen outbreaks in closed settings such as cruise ships, nursing homes and prisons and factors that increase the risk are crowded enclosed spaces with poor ventilation, and interestingly it isn't only coughing and sneezing but it's singing, speaking loudly, or breathing heavily.

This is a typical example that is well-known of an outbreak during choir practice in of SKAGIT county, state of Washingn last March where a single and symptomatic person indicated in red infected 87% of the group who were practicing their choir songs in an indoor space. There are also community transmissions at family gatherings, I'll get back to that in a moment as well as church events where people crowd together without masks.

Right now today in mid to late November we're finding that innocent occurrences, such as groups of friends and family, meeting indoors because of the cold weather for dinner are becoming a major source of asymptomatic spread to the group in the dinner party or in the social event. That seems to be driving infections much more so now than the more obvious settings of bars and other plac which also obviously are important, but we're having the contribution of these family gatherings.

The CDC recently published the exposures and the risks that you have in different places, note restaurants in the top there is very high among it with gyms and bars and various gatherings. Particularly in unmasked situations become a high risk for transmission. And again as I mentioned a little bit ago.

This is particularly relevant as we approach the Thanksgiving season of which we're in and next week being Thanksgiving is the concern that as people travel and friends and family gather together, particularly given the percentage of asymptomatic spread which we'll get to in a moment that is something that is a cause of concern and families need to make an individual decision based on those in the family that might be vulnerable, such as elderly and those with underlying conditions, again all of which I'll get into in a moment.

The fundamentals of prevention of acquisition and transmission are five fold. The universal wearing of masks and cloth-face coverings, maintaining the physical distance that I mentio a moment ago, the avoiding of crowds and congregate settings particularly indoors and certainly wearing a mask must be worn during those instances.

Doing things outdoors rather than indoors is more difficult now because of the colder weather but frequent washing of hands. As I alluded to a while ago one of the most unusual aspects of this disease, this infection is that about 40 to 45% of infected people are without symptoms and we know now from modeling studies that a substantial proportion of transmissions occur from an asymptomatic person to an uninfected individual which makes contact tracing all the more problematic, particularly when you have a high degree of community spread the way we have right now.

What about the clinical manifestatio Early on in infection, confusing matters is the fact that the presenting symptoms are often indistinguishable from a flu and a flu-like syndr One exception though in a certain percentage of people there's a curious loss of smell and taste, which precedes the on set of the respiratory estimates.

Those who do, 80% or so have mild to moderate symptoms that does not require hospitalizatio or significant medical attention other than staying home and waiting until the symptoms resoe as significant as they may be. About 15 to 20% of people however have severe or critical symptoms of which the case fatality rate varies from a few percent among those to about 20 to 25% for those requiring mechanical ventilation.

This becomes so confusing when you have a virus and I've never seen anything like it, where you go from no symptoms at all in a substantial amount to mild symptoms to situations where individuals, because of age or underlying condition, have a serious risk of high morbidity. It's so unprecedented that can as you severe morbidity.

Who are at risk for this severe COVID illness? We have older adults and among those group you see a very dramatic demonstration of the discrepancy between hospital rate per hundred thousand population of younger individuals on the left-hand part of the slide compared to the elderly as you get to the right-hand part of the slide a profound difference.

when you talk about people of any age who have certain underlying medical conditions there are those that are clearly associated with severity of disease and that is individuals with the conditions on this slide. As you can see, I put these in alphabetical order but the ones that dominate are obesity, diabetes, and chronic obstructive pulmonary disease as well as smoking.

Obesity looms large in this. There are those that may confer an increase risk but not as clearly as those on the prior slide and that is hypertension and overweight and cerebrovascular disease, those on chemotherapy. If you look at in our country, what percentage of people have an underlying condition.

It is significant, about 40%, about 30% of the individuals are obese by the definition of a BMI equal to or greater to 30. That's important. Now what about the manifestations of severe COVID-19 disease. The dominating manifestation is the acute respiratory distress syndrome or ARDs but we do see a significant dysfunction.

Cardiac dysfunction by cardiomyopathy and sudden death by cardiac arrest. Kidney and neurological disorders but also a very interesting hypercoagulable state characterized by that can lead to a stroke in otherwise what appears to be normal individuals. There's also a multi-system inflammatory syndrome in children that has also more recently been shown in adults which is strikingly similar in many respects to Kawasaki disease that's been well described in children for some time now.

Another important aspect of this particular degrees is the profound racial and ethnic disparity. Actually, on two accounts one the risk of actually getting infected because as a group though you never want to generalize but in this case it's informative as a group African-American and Latinx, Native Americans have jobs which more likely put them out into the essential workers where they do things that put them in contact with others as opposed to having the capability in their employment to be going through a computer and doing things virtually the way we're doing right now.

And also once they get infected they have much more predominance of the underlying conditions that I mentioned on a prior slide, much more so than individuals in the general population and certainly among the white demographic group. This is a very impressive slide I believe because using the parameter again of rate of hospitalization per hundred thousand population, take a look at the Hispanic, latinx, Native Americans and black non-hispanics in the 400s per hundred thousand compared to white non-hispanics at about 100.

So it's at least a four fold increase in hospitalizations per hundred thousand population a reflection of the co-morbidities that these individuals have. In addition, there is a syndrome that is now being more widely recognized of individuals who clear the virus and so their virologically freed or cleared but even individuals that don't necessarily get hospitalized.

Those who have maybe been at home for a couple of weeks or three or more as well as those who have been hospitalized up to and including people requiring intensive care, in the recovery period after clearing of the virus a certain percent and we're trying to figure out what that is. It looks like it may be somewhere around 25 or so percent but that awaits further study have persistence and when I say persistence I'm talking about weeks to months and maybe even longer of extremely bothersome and in some cases incapacitating symptoms and signs such as severe fatigue, shortness of breath such as athletic people who now have difficulty climbing one flight of stairs, temperature dysregulation or dystonia as they call it as well as tachycardias as they explain some report brain fog or an inability to focus or concentrate one's thoughts.

Let's move onto therapeutics. We at the NIH have put together a treatment guidelines' panel that's constituted by clinicians and people who have experience in treating COVID-19 throughout the country and even the world. They produce a living document that's accessible online at the link shown on this slide that truly is a living document being frequently updated as new clinical data come out either in established publications or as personal experience and pre-publication information.

This has been now accessed multiple millions of times by people throughout the world. Now two of the drugs that have now been recommended by the treatment guidelines are remdesivir and dexamethasone I'll get back to that in a moment, but some examples of things that are now being tested in various levels of trials hopefully and generally randomized role trials are direct antivirals, certain blood derived products like convalescent plasma and hyperimmuno globulin, monoclonal antibodies are looking quite promising and a number of immune -- let's look at remdesivir.

It's been recently reported the study that was done as and NIH sponsored study in the United States and other countries in which hospitalized individuals who had pulmonary involvement were in a randomized placebo controlled trial and showed a significant -- to become the first COVID-19 treatment to receive FDA approval.

Another study from the U.K. is a randomized placebo controlled trial of dexamethasone in hospitalized patients requiring ventilation or high-flow ox and in this study it was shown to have a significant diminution in the 28 day fatality compared to the placebo control. Of note there was no benefit for early patients and in fact it even made them somewhat worse, which actually is in accordance with our understanding of the pathogenesis of cervical versus late disease where early you want to attack the virus to prevent the aberrant, sometime aberrant immuno response, which is the reason why dexamethasone, which obviously is not an antiviral but blunts aberrant inflammatory response is benefit late, and not early and with regard to treatment most recently one of several of the monoclonal antibodies that are in various stages of trial have been granted an emergency use authorization just a few days ago by the FDA for treating mild to moderate COVID-19 disease in patients older than 12 years old.

What is going to shake out I can assure you is that direct antivirals and monoclonal antibodies will be early on in the course of the disease and much less effective as we go later into the cause of the disease. And then finally there's vaccines. So what we did a bit ago my colleagues and I wrote an explanation in science in May of this year several months ago of what we're referring to as a strategic approach to COVID-19 vaccine research and development.

We have been making major investments in six vaccines, which I'll get to in a moment but we're talking about the Harmonization of protocols whereby you can have a common data and safety monitoring board, common primary and secondary end points and common Immunological parameters that can be used for bridging studies between the various vaccine candidates.

So this slide and I want to go through it slowly with you represents the three platforms on the left, the developers, and the stage of clinical study. So we have the nucleic acid platforms which is MRNA from Moderna which was developed in collaboration with the vaccine research center at NIH and then independently Pfizer, bio N tech also with MRNA.

Those trials have been fully enrolled and I'll talk to you about results in a minute. The next is viral vector with AstraZeneca which is a chimp adno as the vector expressing the spike protein gene. Janssen, a subsidiary of J & J is doing an -- use as the expression for the spike protein and MERCK with its VSV which you might remember was used successfully in Ebola and there's from novavax and sanofi.

Five of them are actually in phase three trial. As I mentioned two of them, the Moderna and the Pfizer one results are in. A week ago this passed Monday, Pfizer announced that in their trial they had a situation where there were I believe four infections in the vaccine group and actually five infections in the vaccine group and 90 in the placebo for now they came out literally, today, with the announcement that that's a 95% efficacy.

In the Moderna trial, which was just announced a couple of days ago they again had the same sort of breakdown. Five in the vaccine, 90 in the placebo and 94.5 percent efficacy of note in that trial, a question had been asked does it really protect against severe disease. In that trial, there were zero severe cases in the vaccine group and 11 severe cases in the placebo group.

So what we're dealing with now is a brand new platform that many people had concern about because it was a new platform, which clearly has shown a very striking efficacy signal almost identical in two separate studies done by two separate companies using the same platform and of note both of them showed a very clear difference in severe disease in the treatment group or the vaccine group versus the placebo group.

Now we don't want to get ahead of ourselves because the ultimate decision about how it should be distributed is actually going to be made as usual by the CDC with input from the adviser committee on immunization practices or ACIP. Because of the seriousness of the situation, the national Academy of medicine was asked to weigh in on suggestions for what the distribution should be when you have early on, not enough doses to give to everyone.

This is their breakdown. Be aware that this may not be the final breakdown because the ultimate decision will be with the CDC but it looks like somewhere around high risk healthcare workers and first responders and those in the old age groups as well as those with high risk co-morbidity and after you get to that you go to phase two critical risk people in the essential industries, teachers, staff, et cetera, et cetera but again this is just what the national Academy of medicine came out, the final decision will be made by the centers for disease control and prevention.

One thing you have to mention when you're talking about vaccines is that as you all know in this audience that what we showed you just a moment ago was vaccine efficacy in a trial. Whether or not a vaccine is going to be effective in the community is going to be whether or not people take the vaccine so the two elements are what's the degree of efficacy and what's the uptake? That is going to be a challenge because as shown here in a recent survey published in science that 50% of Americans plan to get the vaccine but what about the rest and this is particularly true -- in the minority population in 37.

This is something that we must address by outreach in the community, by individuals that the community actually trusts. So we've got to get that done and we've got to get it done quickly because we would not want to have an efficacious vaccine at the population level that's not effective because of the lack of uptake.

Here's an example of the kinds of prevention modalities that we've been practicing in the absence of a vaccine. When you have a vaccine that's effective like we have right now what we want to say is that we cannot abandon public health measures, even in the presence of a vaccine that's highly efficacious.

Because it's going to take the community to get completely protected by completely I would say a veil of presentation that has hurt this community. We don't want there to be a central to the community that we have a vaccine so let down your guard. No, it should actually be an incentive to double down until we get everybody vaccinated and what I mean by that is that if you have a vaccine that's moderately effective then what you want to do is you want to make sure you continue in an intense way but we have a vaccine that is really quite effective now, but you still do not want to abandon so many of those other non-vaccine preventive modalities that we know do work.

So I want to end by just putting up this cover of cell of a paper that my colleague David Morens and I wrote and published this past summer and the title, as you can see, is emerging pandemic diseases, how we get to COVID-19 and it really is an examination of the things, particularly the encroachment on environment, the human animal interface that in certain areas of the world has led to the kind of jumping of species and a variety of other factors.

What the bottom line of this is similar to something that we wrote years ago and that is that outbreaks and pandemics have been with us forever even prior to recorded history. History shows us they've been with us for a while within the context of recorded history. We've experienced outbreaks now and we will continue to.

The critical issue is that we cannot prevent the emergence of a new microbe but what we can do is by our preparedness prevent that emergence from becoming a pandemic process and that's going to be the challenge for the future as we learn lessons from the past and we make sure we don't lose corporate memory of what we're going through right now as we go into the future beyond the control of this outbreak.

So I'll stop there. Thank you, again and I would be happy to answer some questions. >> Marcia Day Childress: Thank you, Dr. Fauci. We really appreciate that and a wonderful and up to the minute talk, a marvelous scope of coverage of the current situation. We have a number of questions that have come in through the Q&A and I've been seeing about how these might group so that we might go through some of the things.

I know you actually answered a number of the questions in the course of your presentation and we appreciate that very much. To start and partly because of what has been in the head lines of late, questions about vaccines and about vaccination. So within health systems like this one and others around the country where we're very interested in seeing a strong compliance with vaccination once vaccines are available, especially compliance on the part of the front line healthcare workers.

You know, how do we go about assuring that level of compliance and you know, what does it mean -- what percent of a population even a subset, will need to be vaccinated in order for there to be a herd immunity achieves. >> DR. FAUCI: Let me answer the second question first. We don't know exactly what percentage but the estimates are somewhere north of 75% that you would need probably close to 75 to 80%, if not more to get really good herd immunity.

With measles which is probably the most highly transmissible virus that you've ever dealt with and this one is quite transmissible I might say in its efficiency, that if once you get down below 91/90%, you get a degree of loss of herd immunity that could lead to outbreaks we would like to see almost everybody get vaccinated with this even though I think we can certainly end it as a pandemic if we get to 75/80%.

That's just a guess. The question of how do you get people to be convinced to get vaccinated would depend really on what the reason that they don't want to get vaccinated. If it's lack of access to the vaccine you're going to want to give them better access. If it's skepticism about the process like was this rushed and often we hear and I never like the terminology that was used, operation warp speed, was something that was -- you know, the designated process that we have now, which has actually been quite successful as test to test, the vaccines that have now shown hard degree of efficacy but the speed is really because of the extraordinary technology, the success of a novel platform like MRNA.

The enormous investment in resources to the tune of billions of dollars by the Federal Government to pre-purchase doses so that when the trial showed efficacy you had the doses essentially ready there for you. That is the reason why it goes so quickly. But to impress upon the public the process as an independent decision, independent evaluation of the data by the data and safety monitoring board.

The career scientists at the FDA, the scientists like myself that would look at the data, the VERPAC and the biological advisory committee that FDA listens to carefully before they grant an emergency use authorization as well as moving onto to a BLA or biological license application, all of that is independent and transparent and yet because of a lot of the noise that comes out of Washington in this device of time that we're living in some people may say well I don't really trust that they're trying to rush this out to look good.

Not at all and I can tell you as I colleague of all of us here on this group, this has been an independent decision and it has been done in the classic way that decisions are made about vaccine, safety and efficacy. So I think if we can educate, not only the healthcare providers who you want to get vaccinated right away, but the general public that you're dealing with a process that's both independent and transparent, hopefully we can get a very high uptake of the vaccine as opposed to that somewhat disturbing slide that I showed you towards the end of the talk.

>> Marcia Day Childress: One other vaccine-related question. Is the vaccine -- do you know if either one of these vaccines is effective with A symptomatic positive carriers? >> DR. FAUCI: Well what the primary end point of the study was symptomatic disease, even if it's mild, what we're going to be getting by further analysis of the data is whether it actually prevents infection itself.

When you see if it prevents infection itself you can get a better feel for what impact it might have on asymptomatic disease. What it will do if you look at the end points and protocol as written, if it prevents symptomatic disease but not infection then what it is, it's going to make more asymptomatic carriers which is one of the reasons why we say and have to know if it prevents true infection is why when you get vaccinated that maybe you should still do some of the public health measures because you may not be symptomatic but you might be infected.

>> Marcia Day Childress: Should we be continuing or even beefing up contact tracing in this context once vaccination is available also? >> DR. FAUCI: Well you know contact tracing got hit badly when you have in the community, in the community, when you have such community-based spread, which we have like -- yesterday was 160,000 new cases.

That degree of community spread makes it very problematic to do contact tracing, in fact, you might as well not do contact tracing when you have those many infections. However, if a vaccine becomes utilized broadly the level of background infections is going to be very, very low, which means contact tracing becomes much easier and much more effective.

So if you bring down that baseline then all of a sudden contact tracing re-enters the picture as a very effective public health modality. >> Marcia Day Childress: Again back to health systems, should health systems be testing their workforce regularly, including people who are returning to work, post COVID or who have asymptomatic but positive? And how long is an asymptomatic carrier -- how long does it take them to clear the virus, do we know that? >> DR.

FAUCI: We don't know the answer to the second question, but we feel it is very, very likely around 10 to 12 days or so but again that's difficult because we don't know the true scope of the asymptomatic individuals. Be careful when you say clear virus. You want to talk about clearing replication competent transmissible virus because we're finding that people when you do PCR they have high level cycle thresholds in the 30s, 35/36 which essentially is the functional equivalent of negative in that they're not transmitting even though you do pick up by PCR but getting back to the first part of your question.

I strongly believe that we should do surveillance testing intermittently on various groups that we want to get a handle on whether or not we're having silent spread and I think that would be true of healthcare workers. You know, I still see patients at the NIH clinical center and I get tested frequently.

I mean every time I walk into the building really I go up and just get a quick test. So far now I have been tested for COVID 54 times. >> Marcia Day Childress: So some questions too and I'm glad you emphasized that even with availability a vaccine once those are in the works, the continuation of some of the non-pharmaceutical interventions and about masks and one practical question if a speaker, a preacher, or somebody talking in Congress is unmasked but 20 feet away but indoors, is that okay? Or should we be expecting to see them masked for our protection? >> DR.

FAUCI: You know that's really a great question. There's not a scientific study that showed that but if you believe, which I do, that aerosol is a component of transmissibility. What I don't know is how much of a component, but if that being the case when you are indoors, even if you're 20 feet away in a closed space with poor ventilation it is conceivable that with aerosolized spread that you could have an aerosol -- a virus that's aerosolized that can go that 20 feet.

It probably is unlikely. You know, we haven't seen outbreaks of situations where people were indoors, where everyone was masked but when they took -- when they went to the microphone and took the masks off that there was any spread under those circumstances so if it does occur it is likely rare or unusual.

Though if you really want to be careful when you have the kind of hot transmission like we're having now in the country and you're indoors, that it might be the better part that even when you are speaking in a smaller room, maybe not such good ventilation that you might want to keep that mask on because of the aerosol.

>> Marcia Day Childress: Okay. So we've also had a cluster of questions that look forward, particularly into the transition to the next administration. You know, questions about how will COVID policy and things change with that change? But I think also there's a question about -- what about federal versus state by state protocols for precautions but also now also for the protocols for vaccination and distribution of vaccination? >> DR.

FAUCI: Yeah. A bump of questions in there. Let me just I think focus on the important one is that I have always been in favor of recognizing the individual differences from state to state but there are sometimes when you have a situation like we're in now where strong recommendations from centrally to the states should be made.

States don't like to be mandated for anything nationally but you can make a strong recommendation about anything from public health measures to the distribution of vaccines even though at the local level that's the final decision to do I think we should try and give some pretty clear guidance about everything from the public health components of it to how you distribute the vaccine according to the recommendations of the CDC.

So you want to give some flexibility to the states but they often even ask for some significant guidance. >> Marcia Day Childress: So we're coming to the close of our hour and I will just -- understanding that this is a topic that's going to continue for a while. Your thoughts what we have learned thus far from COVID and it's management that will help us not only now but in the next pandemic because as you said there will be more.

>> DR. FAUCI: Yeah I think what we've learned is something that we've learned with every outbreak is that pandemics occur. They take you by surprise. Hopefully not by surprise with regards to preparation but they're unpredictable and they evolve. I mean what I think we need to realize is that when an outbreak occurs of a brand new infection we've got to be humble and we've got to be monitoring things really carefully and flexible in that what you think you might know on day one, two, three, four, five, may not be what actually is happening two or three months later.

I refer to, for example, our not fully realizing the extent of asymptomatic spread early on. Thinking that it was classic -- a sick person transmits it to an uninfected individual as opposed to the degree of silent community spread. We didn't know that in the beginning. We know it now but I think one of the lessons is keep an open mind, be flexible, and be humble in that you don't know everything literally in the beginning of an outbreak.

You've got to learn as you go along. >> Marcia Day Childress: Sounds like wisdom for now and the future. Dr. Fauci, we thank you so much. We are so grateful for your time with us and for the very good work you're doing, many of our questions began with an enormous thanks for your great public service.

As a scientist and as a spokesperson for this. So with this, we close not only this Medical Center Hour but the Medical Center Hour series for the fall semester. Medical Center Hour will return in the new year, February 3rd, 2021.