Explaining The Coronavirus: Researcher Tackles Top Questions About The Outbreak

In December, the novel coronavirus — since named COVID-19 — popped up for the first time in Wuhan, China, and has dominated the news cycle since. As a faculty member at Boston Children's Hospital based out of its Computational Health Informatics program, Dr. Maia Majumder has been at the cutting edge of research into the virus and has taken on a public role in speaking of epidemic patterns and projections. She spoke with WGBH News about the virus, its development and its effects — both physical and social. This interview has been edited for clarity.

Editor's Note: This interview took place before the Centers for Disease Control and Prevention issued a warning to Americans to be prepared for more intrusive measures as it attempts to delay the disease's spread to the U.S.

How do new viruses come into being? What circumstances create the opportunity for something like COVID-19 or the 1918 Spanish flu to pop up?

Most human diseases — especially those that are caused by viruses — are zoonotic diseases. And when I call them zoonotic diseases, I mean they are diseases that jumped from animal species into humans. So, what we end up seeing is when the human-animal borders are more porous, we have a higher likelihood of zoonotic jumps occurring from animals to humans. And these spillover events, as we call them, are becoming more and more common nowadays because the porousness of that border is increasing over time. Some of the things that motivate that porousness are climate change and deforestation. Deforestation, especially, is one of those things where the closer humans get to animals, the more likely it is for these kinds of events to occur.

Could you help put COVID-19 into context? Is there enough data yet to compare it to other viruses like SARS, HIV and the Spanish Flu?

I think that we're still very much in the early phases of this outbreak. It's really only been a handful of weeks. And, with that in mind, I think that we're learning about this virus faster than we've learned about other emerging and reemerging diseases in recent history. I think that makes our knowledge capabilities much better than they were, say, during even SARS 17 years ago.

I think that one of the things that's motivating how quickly we're learning about this disease is how openly scientists, such as myself, have been sharing the things that they've been finding as they've been finding them. And that culture of open science is definitely improving the rate at which we're learning about this disease, even though it's only been a handful of weeks.

What is the U.S. doing right now, or what should the U.S. be doing right now, to prepare as the outbreak continues to spread? Right now it's hitting Central Europe and Italy is the country being hardest hit outside of East Asia.

Pandemic preparedness is one of those things that when you prepare for one pandemic, or possible pandemic, you prepare for many. One of the things we need to keep in mind is the pressure that we put on our health care systems when we have outbreaks like this that happen to coincide with the flu season. So, one of the things that I think that the U.S. probably needs to be focusing on the most is our ability to tackle the possibility of this kind of emergent disease in the middle of a flu season that has already caused 36 million cases arriving in the U.S.

The other thing that we really need to be focusing on right now is diagnostic capabilities. And that's always really tricky with a new disease because when you have a new condition, it's one of those situations where the case definition may change over time. The way that we diagnose it may change over time.

Can you explain what R0 is for the non-med school trained audience?

Let's start off with what we call R'naught. So, the basic reproduction number is a measure of potential transmissibility. It's a measure of how likely it might be that a given disease in a given population at a given time will cause sustained transmission. What this means, kind of in the broader scheme of things, is that at the beginning of an outbreak — especially of a novel disease like this one — what we're always very curious about is whether or not that new disease has the potential to cause an epidemic or to cause a pandemic.

So, very early in this outbreak that was one of the things that we were concerned about. Now, we're about 80,000 cases into the game. We clearly know that it has epidemic potential. But early on in an outbreak, we want to be able to somewhat quantify whether or not we should be planning and preparing for this kind of event to occur. Generally, the consensus is that if the estimates for R0 are greater than one then there is a possibility that this kind of disease may cause an epidemic in the population of interest. So, with that in mind, what we ended up finding was somewhere between two and three and that has been since validated by several other groups who have done their own estimates. And that seems to be around the ballpark that we're looking at right now.

Now, what does that mean exactly? So on average, what that means is that an infected person and a fully susceptible population will cause on average two to three more infections. But the thing is, this is kind of a really rudimentary explanation of what this parameter actually is and the reason why I say it's rudimentary is because it's an average, and averages are notoriously bad at kind of capturing the way that humans work. A big part of that is when you take an average, you're trying to consider the average of an entire population, right?

So, for example, let's say I get sick, and I infect zero people. But then you get sick and you infect 10 people. In that case, the R0 IS five, right? But if that's true, what that also means is that eventually this will probably die out, because a lot of people are going to infect zero people and some people are going to infect 10 people and so on and so forth. So what we care about ultimately — and this is the kind of research that's going to be very important moving forward — is what that spread looks like. Is it that most people transmit the disease to two to three other people? Or is it that some people transmit it? A lot of people and most presidents, nobody or just one person. And that's something that we don't fully understand yet. So, that's why this measure, though, it's useful for trying to figure out whether we need to be planning and preparing for an epidemic. It doesn't tell us too much about how big an outbreak will get. That's kind of why I like to call it a measure of "transmissibility potential" rather than what the "transmissibility" actually is.

How do you define pandemic vs. an epidemic?

That's a good question. The best distinction is that an epidemic is generally constrained geographically, whereas pandemics are not. So that geographic constraint is really important. I think what Dr. Tedros Adhanom Ghebreyesus [director general of the World Health Organization] said was that what we're seeing right now are lots of epidemics in many parts of the world, but it's too soon to call it a pandemic. That's one way to describe it.

Now, I think that the reason that he's describing it this way is that the size of these outbreaks are still very variable. And more importantly, perhaps, it looks like the epidemic in China is starting to wane a little bit. So, with that in mind, it makes it a little bit harder to kind of make this kind of classification.

I think that's part of the contention right now that the WHO is focusing on confirmed case counts, which makes sense, and they're focusing on cases that have been diagnosed. Whereas some scientists are really suggesting that there may be many mild cases that we're not capturing, in which case perhaps this does qualify as a pandemic because we're only catching the tip of the iceberg so far.

So, what should people be doing to protect themselves from from this? Is it pretty much the same thing that you do to protect yourself from the flu that hits us annually?

Yeah, I think that especially in the U.S. and in other countries that have not had really kind of any indication of prolonged, sustained transmission. I think that the best way to prevent yourself from getting sick from something like this new coronavirus is the same thing that you do to prevent yourself from getting sick from the flu. And that's things like wash your hands often, cough into the crook of your elbow, make sure not to touch your eyes, nose, ears and mouth with your hands if they're not clean. That sort of thing.

It's one of those situations where preventing one disease prevents many others. Prevention is definitely a big priority, I think, right now in the U.S. The other thing to keep in mind is get your flu shot. And the reason for this, which may be somewhat counterintuitive, is that if you get your flu shot and then you don't get the flu, you're less likely to end up in the hospital. And, if you're in the hospital, you're more likely to pick something up.

And, bringing it full circle to what we talked about earlier about our health systems and whether they are robust enough to manage multiple different types of outbreaks at once. If there are fewer people with flu, then it makes it easier to manage other respiratory infections because we only have so much capacity for respiratory infection.

This virus started in China, and it's been widely reported that it's been hitting Chinatowns hard economically. Is this something that we see come that we commonly see with epidemics in your experience, where certain groups get singled out as a result of an epidemic’s origin?

Yeah, I mean, it's it's a very sad reality of epidemics for sure.

The stigmatization of origin countries is really, really common, no matter what the outbreak is. And I think that many Chinatowns in the U.S. probably have far enough historic memory to remember what things were like during SARS as well. So, this is not the first time for a lot of Chinatowns.

I think that that's a very unfortunate kind of repercussion to all of this. And stigmatization is a very serious problem. It's an angle to all of this in terms of outbreak research that is somewhat neglected. And I think that it's really important to shed light on that, because this is definitely affecting people's emotional and mental well-being, too.

What could people in he epidemiology field, like yourself, do to combat at least that aspects of the epidemic, the stigmatization of groups?

I think that one of the things that we need to do a better job of is really kind of make clear that these kinds of epidemics. They can happen anywhere. There are people in contact with wildlife, which is basically anywhere in the world. And we see the emergence of diseases in many parts of the world. I think that some of that randomness is probably really worth emphasizing.

The condition does not know what your race or what your ethnicity is. The issue is whether or not you have exposure to somebody who is sick with this thing. In the end, being prejudice against folks that happen to be from the place where this new virus originated from is not useful to anybody.