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The Q&A: Dr. David Ho talks coronavirus pandemic, slowing the spread

CEO of Aaron Diamond AIDS Research Center has had long partnership with NBA

Dr. David Ho, Director and CEO of the Aaron Diamond AIDS Research Center, is an expert on viral epidemics and has been at the forefront of the global battle against the HIV/AIDS epidemic. Dr. Ho first worked with the NBA when Hall of Famer Magic Johnson announced that he had been diagnosed with HIV.

Today, Dr. Ho spoke with’s Brian Martin about the coronavirus pandemic to emphasize best practices for slowing the spread of COVID-19, clarify common misconceptions about the virus and discuss the work he and his team of researchers at Columbia University are doing to help find an answer to this global threat.

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I wanted to begin by discussing how the virus spreads. Everyone keeps talking about washing your hands. Why is that so important in terms of how the virus is spread?

The virus lives mostly in the airway of an infected person, which includes the mouth, nose and all the way down to the lungs. So when a person coughs, sneezes, or even talks with droplets coming out of the mouth, that is potentially infectious. And quite often the droplets will land on surfaces and we now know that the virus can survive on surfaces for hours to days. Therefore if one touches the surface, then brings it to one’s mouth, nose, or eyes, that could then allow the infection to take place.

Seldom do you witness someone coughing into someone else’s face. Obviously that is more direct, but we know from many other respiratory viruses that quite often hand hygiene is the most important. Of course, covering up the person who is infected helps, so an infected person wearing a mask will also help decrease the risk of transmission.

A lot of people are saying young, healthy people aren’t affected that much, and if we get it, we’ll just feel flu-like symptoms. Is that true or more of a misconception?

It is largely true, with one caveat. Let me just say that the death rate, the mortality rate, is much, much higher in people over 65-70 years old; there is no doubt about that. So the elderly and those with cardiac pulmonary conditions generally do worse. If you look at all the cases that are in the ICU with severe [complications], you will see predominantly elderly folks or people with underlying problems. However, there are cases of people who are in their 20s, 30s, 40s and 50s, and we don’t quite understand why a small minority of the younger folks get severely ill. It could be genetics, it could be something else, we don’t know that yet. So one should not say ‘Well, I’m young, I’m not going to have any problems,’ because you’re rolling the dice. It is true that a large majority of young people will just suffer a cold or flu-like illness and recover and do just fine, but there is a small percentage that will suffer a great deal and possibly die.

What does ‘community spread’ mean?

Before we had cases in the U.S., we were concerned about importing cases, but we’re way past that now. You could say just about 99% of our cases are community spread, that is new cases acquired within our own communities.

Another term that we hear a lot is ‘flatten the curve’ in order to slow the spread of the virus. Can you talk about not only what ‘flatten the curve’ means, but why it is so important and if you are seeing any indicators about where we currently are on that curve?

When you have an epidemic, let’s take influenza or flu, any given season as the winter approaches you’ll see the case number rise, which is typically exponential. As the season continues and enough have caught it, the number generally comes back down as the weather warms up. So you almost get like a bell shaped curve.

Here, in this case, we are trying to flatten it, so we’re trying to take that bell shaped curve and push it down so the peak is not so high. So instead of having a few million infections, we want to keep it under that, let’s say hypothetically a hundred thousand cases. When you push the peak down, you avoid the surge in the number of really sick people presenting to hospitals and really overwhelming the hospital system. When you overwhelm the hospital, you have greater mortality because the hospitals cannot provide adequate supportive care. So flattening the curve means pushing that peak down and letting it spread out over a much longer period of time so that the health care system can absorb the caseload.

Something that is generally not understood very well is that if you don’t have a solution for this infection through medical science, while you flatten the curve, the curve will continue, meaning that you’ll continue to accumulate cases. So flattening the curve is also buying time for science to deliver potential solutions, treatment and vaccines.

You mentioned earlier that the virus could live on surfaces for hours or days. Is it OK to touch things like doorknobs, cell phones and keys? Are there preventative measures that we should be taking?

This is teaching us to frequently clean, in particular, things that many people will touch each day — doorknobs, handrails, elevator buttons and such items where you can have hundreds or thousands of people touching them. They need to be cleaned frequently, but more importantly, each individual should take care, if they have touched those things, to wash their hands, or if there isn’t water and soap convenient, to use the hand sanitizers, so the hands are always kept clean and you’re not going to bring virus to your nose, mouth or eyes and mucosal surfaces.

I still have to go to the grocery store from time to time to buy food. Can the virus live on fruit that is handled by others? What about the credit card kiosks? Bag handles? Are there precautions that we should be taking to avoid risk?

First, make those runs for essential items as infrequently as you can to minimize exposure. And when you’re there, you just have to be very, very mindful of what you’re touching and then be sure to clean your hands afterwards. I know that many supermarkets, for example, will only allow in a certain number of people at any given time. I think that’s a good practice, and if there is a line outside, the line should be quite spread out so that people are not tightly packed; all of those things will help minimize contact. The probability of infection is a reflection of how many contacts you have and the nature of those contacts, so if you have fewer contacts and you also protect yourself, then you can increase the likelihood of not catching the virus.

And with items you bought, if you’re going to cook them, then they’re probably going to be fine because the virus is easily killed by high temperature, and anything that will cook our food will kill the virus. Foods that you eat fresh obviously need to be washed properly.

I’ve heard if I have a wet cough or a runny nose, those are signs that I don’t have the virus. Is that true, and is there a way to know the difference between having a cold, a regular flu and having the coronavirus?

I think if your symptoms are predominantly a runny nose without a fever, that’s unlikely to be COVID-19 infection because runny nose or sniffles have not been reported as a common feature of the clinical symptoms of COVID-19 infection. We have to bear in mind that people could be asymptomatic. However, [for people] who are symptomatic, fever and dry cough are the most common symptoms, and for some cases, there could be some gastro-intestinal symptoms. You may have heard that a lot of COVID-19 patients complain that they lose their smell and taste, which is something we don’t understand yet. But it is a common complaint by patients.

If I’m home and feel sick, what should I do? What should others in my home do?

If you’re sick with fever and cough, and at home with your family, you likely should stay home, but away from the rest of your family. Given the current testing situation, the medical system probably would not put you as a high priority for testing, which is tragic and sad, but that’s where we stand.

You should monitor yourself, and the major [symptom] to look out for is shortness of breath. If you find yourself having trouble breathing, then you should contact your physician, and if the physician deems the shortness of breath severe enough, then you would need to be seen at the hospital. But short of that, based on current information, approximately 80 percent of infected people will just have milder or no symptoms and recover on their own without ever having to go to the hospital.


 … We don’t quite understand why a small minority of the younger folks get severely ill. So one should not say ‘Well I’m young I’m not going to have any problems,’ because you’re rolling the dice.

Dr. David Ho

What should I do if I feel flu-like symptoms but cannot get tested? Should I treat it the way I would the flu with lots of liquids and medicine to keep the fever down?

The majority of cases will resolve on their own without any specific treatment, other than taking Tylenol or one of the anti-inflammatory drugs to reduce fever and make oneself more comfortable. And yes, hydrate and rest. That is going to be the case for most cases. If shortness of breath becomes a concern, you should seek additional care.

If you get the virus but then become symptom free — I know a few NBA players have gone through this where they had it and have fully recovered — can you get it again?

I think you are asking a very important question that is not yet fully answered. We know that 17 years ago there was the SARS outbreak, and in that outbreak we could not find any evidence of reinfection, the kind you are talking about, catching it more than once.

Now, for [the coronavirus], we still don’t have the answer for that. One experiment has been done in monkeys where they were given the virus; the monkeys got infected; and then after they recovered, the monkeys were given the virus a second time. That second time, the virus did not take. So that may suggest that there is immunity that protects us against reinfection.

Another term that has been discussed is ‘herd immunity’ where if many people get the virus, recover from it and become immune to it, then the virus would not be able to continue to spread. Would ‘herd immunity’ help, so once we pass this first peak that it wouldn’t peak again?

Herd immunity definitely could help. Say you are the one person who has never been exposed, but you are surrounded by 99 others who have immunity and the virus comes in. Unless it hits you directly first, if it hits the other people, the virus would not penetrate into this community. That’s what is meant by herd immunity: you’re protected, even though you yourself do not have immunity, simply because those around you are pretty well protected.

Herd immunity works well when a large percentage of the population has immune response to the virus, which would mean probably something north of 50 percent, or 70 to 80 percent, in order to be somewhat protected. But by then, that also means that a large fraction of our U.S. population would be infected already. So while herd immunity is something that could be built up over a long period of time, in the short term, if we build up herd immunity in 75 percent of our population, that’s going to mean over 200 million people are infected this time, and that, of course, would come with terrible consequences.

We know that your team at Columbia University is working on strategies to cure and prevent the coronavirus in the future, what can you tell us about your work?

We’re trying to do a number of things. First, we’re trying to find drugs that block the replication of COVID-19 and we’re going after two critical sites in the virus. The virus needs some of these important enzymes to replicate and one of them is called protease, which is a chemical scissor that cuts the viral proteins from big chunks to smaller pieces, which can then fit into the virus particle itself. And somehow, if you’re able to use a drug to gum up this chemical scissor, then the virus can no longer cut the proteins, and therefore the progenies that are made by the virus will be dead. And so we can interrupt the replication cycle that way.

Another target is what we call polymerase, which is the enzyme the virus uses to replicate its genetic material. So, in this case, it’s RNA to more RNA, and we can find drugs that will inhibit that copying of the genetic information.

We picked these targets because both areas have been well worked on in the past for HIV and Hepatitis C drug development, and many, many drugs are already available that block one of those two enzymes for HIV and Hepatitis C. So we’re bringing a lot of knowledge and experience from those areas to coronavirus. That is one principal area that my group is involved with.

Another area that I would just put out there is we’re trying to study people who have recovered and have developed a very strong antibody response to the virus. We are trying to fish out the very cells that make the strong antibody response so we can clone those cells and clone the antibody, and produce it in large quantities to be administered as treatment or as prophylactic for patients. Those are some of the principal activities; we’re doing more, but that covers a pretty broad territory in the area of treatment and prevention efforts.

Is there any sense of a timeline between the research you’re doing, to something that could be tested and then something that could be implemented?

Normally, I would tell you if we are not pressured to move fast, this would be a 5- to 10-year endeavor. But now, because of the urgency of the situation, we are all trying to move at a faster pace to see if we can contract this [timeline] to one to two years. I think if we are really lucky we may have something in a year or year-and-a-half. But I think as a society, we need to prepare that, in all likelihood, some of the scientific solutions that will be brought forward will not arrive until about two years from now. And that is why we need to flatten the curve and keep it under better control, and hopefully science will solve the rest of the problem.

As difficult as the situation currently is, we’d like to end on a positive note. What can you tell us or have you observed that we can be hopeful about?

Let’s look at what has transpired in China and in South Korea. They both had substantial epidemics and both implemented very harsh measures to either lock down or mitigate the spread of this virus. And China went from a peak of 4,000 new cases per day down to a point where a few days ago [there were] zero new reported cases. South Korea also had a very bad outbreak in part of the country, and then without implementing lockdown, but instead everybody carrying out good practices of social distancing and hygiene and so forth, it too has largely brought the epidemic under control. So I think these two examples tell us it can be done. And there are other places in Asia — in Taiwan and Singapore — that have done a fantastic job of keeping the epidemic curve essentially flat. So we know it could be done, but at enormous sacrifice obviously. And it’s important that the practices are carried out by everyone throughout the country.

I think we are seeing varying degrees of responses by states in the U.S. We are seeing wave after wave of epidemics; obviously the two coasts got hit first but the center of the country is now beginning to experience the next wave and this will move to rural America as well. The positive news is that [improvement] could be done, but we need to hunker down and put up with it for a good six to eight weeks. That’s what it takes to drive the infection down to a low level and then we can begin to relax and try to return to some semblance of normalcy.