As we continue to navigate these unprecedented times, KCBS Radio is getting the answers to your questions about the coronavirus pandemic. Every morning at 9:20 a.m. Monday-Friday we're doing an "Ask An Expert" segment with a focus on a different aspect of this situation each day.
Today we're looking at health issues with Dr. David Agus, CBS News medical contributor and professor of medicine and engineering at USC.
I know your time is limited so we're gonna jump right into them this morning. Can you tell me what we really know about how long this virus stays active in different environments? Seems like there's so much information out there and I'm not sure what to believe.
So the CDC made an announcement this week. It wasn't really new, but what they said is the majority of spread of the virus is through droplets, and so surfaces are not as common. And that is totally accurate. So you can get it from surfaces but it is relatively rare. Droplets are the most dominant form. Droplets fall to the ground by gravity. Better ventilation means they get away from you much better, as well as the UV light of the sun. So out of doors is certainly much, much better. But the virus itself could live on different surfaces anywhere from an hour to potentially several days. But there is not a lot of virus on the surfaces, so we don't think it's a dominant mode of transmission.
Okay, the next question kind of touches on that. What do you make of the CDC's changing recommendations on disinfecting surfaces?
I don't think it was a changing recommendation, it's just making people aware that droplets are it. And when everybody is saying, "wear a mask, don't wear a mask," and there's relatively poor compliance in the country, this is what's alarming. This virus spreads predominately by droplets. When you speak, when you breathe, droplets go out of your mouth and in close contact with somebody else, these droplets can spread the virus. If we wear a mask, we block droplet spread enough that we will dramatically lower spread of the virus and the country will do much better. It's not rocket science.
I never enjoyed smoking and never liked secondhand smoke. So that being said, if a person exhales while smoking can the virus stay with the smoke longer or have a better vehicle to travel on for infecting others?
It's a great question and I don't know that answer. I don't know if it's been studied. But certainly avoid people who are smoking. Second hand smoke isn't good by itself. But it's a very interesting question. Does it affect the kinetics of the virus? I don't know.
Okay, next question. What is the death rate from this disease? Seems after several months we should have a good idea of just how deadly it is so we can make informed decisions about how to live our lives.
The current estimate on the death rate is 0.4%, which puts it at two to three times the average flu death rate. So kind of a super flu in that regard. It may change a little as we get more testing, but that's where the data are today.
Can you ask Dr. Agus what he thinks about the vaccines being developed? I think we're stuck in this current mess until there's a vaccine but I worry that the news reports have been too optimistic.
Well, if you looked at my face right now (which you can't because we're on radio) you would see me smiling. I actually think there's real optimism around the vaccines. There are five efforts that I've seen the data on where the science is really good. Realize there are... many vaccine efforts across the globe. But five of them have remarkable science and are really building on things that have happened over many, many years. So it's not like they created this vaccine from scratch where we're worried about what it'll do, but we're actually seeing data now after it's been injected into thousands of people. We're seeing good immune response, good durability. Over the next several weeks, we're going to start to get initial data. Does it work? Because the real question is, the immune response that we're getting: can they block the virus or are they neutralizing? Can they block the virus from getting inside our cells? And we're gonna get that answer soon. But I have cautious optimism that we will have a vaccine in the fall. And the government, as you know, is already starting to produce them in case they work. So if they work, that next day we could start to inject people and hopefully save a lot of lives.
And real quickly my side question here would be, can we make enough to make a difference?
Yes, and so the government is doing at-risk manufacturing, which means they're actually paying to manufacture five of these vaccines in case they work. So not all of them will. Each probably have about 50-60%, so if you were a betting person, it means probably two, maybe three of them could work. And we'll have millions of vaccines, you know, hopefully in the early fall. And those will go to frontline healthcare workers, very high risk individuals. And then over the next months as we make more and more it will hopefully go to most of the country.
Next question. How likely is the virus to be transmitted through your eyes?
There's a lot talked about but very little data on it. It's certainly possible that if there is a significant viral spray to the eyes, you can get infected in that route. In general though, it's breathing in the droplets deep into your lungs that is the dominant mode of infection. I don't think it's a very common mode of infection but it is possible.
Next question, assuming that scientists are able to create the first ever vaccine for a human coronavirus and are able to mitigate COVID-19, would that potential vaccine give us a head start on the next coronavirus pandemic or even the viruses we already have? Or do the coronaviruses that cause some of our common colds mutate too quickly for that to be possible?
Great question. So this particular coronavirus vaccine, at least the ones that are leading scientifically now, are targeting something that is remarkably novel to COVID-19: part of that spike protein. And so the vaccine will be specific to COVID-19. The exciting part is that there has been no mutation in this area where the vaccines are targeting and if the virus actually mutates or changes in this area, it won't bind to a human cell. That's why this area was chosen. So it is targeting COVID-19.
But I think what you'll see is, we're gonna validate this whole new wave of vaccine platforms. So in the future, when something happens we will be much quicker to a vaccine because we're validating this big scale-up process, the whole new way of producing and scientifically developing vaccines. That part I'm excited about also, and that holds for the future that we're not gonna go through what we went through here, where we were remarkably unprepared.
My question is about the care/treatment patients receive while in ICU and we see or hear of patients released from ICU units reported they were treated in the hospital. What kind of treatment did they receive since there's no vaccine and antibiotics don't work on viruses?
Well, we have a particular antiviral called remdesivir that has been shown now in a randomized trial to shorten hospitalization by about 40% and have a reduction - although not statistically significant but close - of 30% in the death rate. So intravenous remdesivir was given as well as what we call convalescent plasma. Those are antibodies from somebody who's recovered being given to somebody who actually has the virus. And you couple that with ways to help breathing and so you enable time for your own immune system to kick in and hopefully get rid of the virus. Those are the three kind of basic tenets that we've been using and they've been very successful. In fact, there's been dramatic improvement in the number of people who get off ventilators and get out of ICU. So if you get sick today, the outcome is going to be much better than if you got sick several months ago.
I have a trip planned to see my aging parents on the East Coast. When I land should I get a COVID-19 test and/or do you feel I should quarantine myself for 14 days before seeing them in their home?
It's a great question and it really depends on an individual's level of risk tolerance. So if you and your parents say, "hey listen, we're really healthy, we're younger," then it certainly makes sense that if you've been quarantined, you can fly there and potentially see them. If they're very high risk and you're remarkably concerned about them, getting tested before or quarantining yourself before you see them makes sense also.
So it's hard to give an individual answer; it depends on your level of risk tolerance. And we're all gonna have to do that for ourselves now, as we get away from stay at home orders. We're gonna have to decide what is our level of risk tolerance and what is our level of risk with the exposures we've had, before we see people who are higher risk.
Let's fit one more in because I know you're on a schedule. This one says I follow a lot of news out of Europe, and I often see references to the coronavirus reproduction rate. That doesn't seem to be very much publicized here. Can you explain this?
So there's something called R0 (R naught), which is basically how infectious a virus is. And it depends on a lot of data. The data is how many people have the virus, how it spreads. And you really need very accurate testing data. In that, we haven't had accurate testing data in the United States to date. It's very difficult to give an accurate R0 initially. In China it was felt to be less infectious. Now we think it is significantly more infectious than we originally thought, and as that number goes up, we get more worried about the virus. So we do think it is dramatically higher, but without really accurate input data it's hard to give an exact number for that figure.
We're working on a project asking everybody who's ever had to put on a medical mask how they keep their glasses from fogging up. What do you do?
I put a piece of surgical tape at the top of my mask. I need reading glasses or I cannot read a thing in the patient's chart. So I put that little piece there, that tape. So there's a barrier there and it works, for me at least.
