News at Buckley

Follow-Up with Infectious Disease Specialist Dr. Tyler Evans '95

At the outset of the coronavirus outbreak in early February, we interviewed Dr. Tyler Evans ’95, an infectious disease specialist working as Chief Medical Officer for the Santa Cruz County Health Service Agency. 
Since then, he has moved from California to New York, where he has been appointed the Chief Medical Officer for the New York City Office of Emergency Management. He also is an associate professor at USC, founder of the New York City Refugee and Asylee Health Coalition, and has previously led several national organizations, including the AIDS Healthcare Foundation. 

Director of Communications Sally Sacon asked Dr. Evans if he would follow up with us on recent developments in the Covid-19 pandemic and provide some insights based on his professional expertise and what he’s seeing in New York City.

Sally Sacon
: You are an infectious disease specialist and have worked very closely with Ebola in Africa. How does COVID-19 differ, for the most part, from other infectious diseases?

Dr. Tyler Evans: 
 It has really spread throughout the populations in a way that we just did not really expect. So, for comparison, COVID-19 is a beta coronavirus and there are several beta coronaviruses, including CoV-43, which is a common cause of the common cold. Probably 10-15% of the population has been exposed to it. Also, within the beta coronaviruses are MERS and SARS-1, or SARS-CoV-1 from 2004. SARS stands for Severe Acute Respiratory Syndrome and MERS is Middle Eastern Respiratory Syndrome. So, they are all in the beta coronavirus family. SARS-CoV-1, and SARS-CoV-2, which is COVID-19, are quite genetically like one another, consider them brothers. MERS is sort of a distant cousin, CoV-43 also a distant cousin. My point is that these beta coronaviruses in general have been around for as long as we have known.

But the reason you hear novel coronavirus often is that it is not an exclusive term to COVID 19. It describes the three outbreaks that have taken place in 2004. They all have to do with transmission, transmission from an animal to a human or non-human to human. It is because we do not have immunity to these viruses because, by virtue of us lacking prior exposure we could not develop antibodies to these viruses. That is ultimately the reason why they have such a severe impact on the population. So, it is really the outcomes of the beta coronaviruses and the efficiency of transmission that are different than other sort of viral infections.

Sally Sacon:
 People are talking about various paths out of this into restarting society, restarting the economy with a vaccine, treatments, testing, and herd immunity being mentioned. What do you see as the key to our path out of this?

Dr. Tyler Evans:
 I think it really needs to be regulated, reentry into society. The Germans are doing something very similar. The Germans, by the way, have probably one of the lowest fatality rates in the world – it is around somewhere between point .04-.07% – quite good for a country. Through these regulated waves of relaxation of quarantine and strong recommendations to stay home, by creating those waves of infection, you create a controlled opportunity for people to actually get infected.
I know it sounds sadistic, but we need the healthier population to get infected over time and that ultimately leads to what you refer to as herd immunity. Herd immunity is defined as getting to a point where a population at risk can either generate antibodies because of vaccination/inoculation (not the case here), or as a response to the disease through infection. So you get to a point where so many people are immune that they can no longer be infected. And therefore those who have not been infected are essentially no longer at risk. If that makes sense.

Sally Sacon:
 Yes. What about wiping down your groceries, your mail? A lot of people are doing these things in case there are microscopic droplets on a package.

Dr. Tyler Evans:
 The Royal Princess in Japan was basically the best data that we have, because it was a floating Petri dish. It was a controlled environment where we could test everybody and observe the natural course of infection. With that, they were able to extract some viral material on surfaces. There's controversy over the types of surfaces and if the particles can last longer on metal or whatnot, but it was on the material for 17 days. Whether or not that is a sufficient viral load that causes transmission is not clear and it is very doubtful that it would be. For the most part, if something is on an inanimate surface, a non-animal or non-human surface, it is very low risk.
It is very low risk and the longer it remains in the environment, the less likely it is to cause disease transmission. But if you are, for example, getting the mail and opening it up, before you touch your mouth make sure you wash your hands. That is really the most important thing when it comes to this—and it is unfortunately getting missed by the public. There are people so fixated on wearing a face mask, but the most important thing you need to do is wash your hands thoroughly and not just use hand sanitizer. 

About kids…You know, fortunately kids and pregnant women seem to be at lower risk of infection and probably disease progression, more so for kids we have seen. I think that is mostly related to a stronger immunity, right? Kids are exposed to so much, right? They are constantly doing things they should not be doing and putting things in her mouth. They also have innate immunity, which is strengthening or potentiating the humoral immunity, I don't want to get too technical, but humoral immunity is the concept of generating antibodies and then innate immunity is a component of your immunity that helps us create the scaffolding for that. Kids have a lot of it; it is very strong for that because the body is growing and capitalizing. So, it is largely that they are not getting sick. Kids can still get sick with other viruses. Why they are not getting so sick with this is not exactly clear. 
With pregnancy it is not clear, but they certainly do not seem to have any teratogenic effects. So, this is good news because when it comes to certain diseases like malaria, malaria has a predilection for pregnancy and for small children and that is your worst possible outcome, right? So, it is good that it is that is not the case with COVID.

Sally Sacon
Yes. So, if you could hold school with just children in it, no adults supervising them, you would be fine.

Dr. Tyler Evans: Yep.

Sally Sacon: There are a lot of students, current students, I know who are really eager to help and to help the cause and who are looking forward to how they might be the most useful in whatever “new world” we're left with. What will be the needs for the next generation? Can you speak to that at all?

Dr. Tyler Evans:
 You know, I have always taught students and residents or younger folks to really move through life with their moral compass. We might have different exposures in life, different privileges, different outlooks, political leanings and whatnot, but ultimately if your moral compass is heading towards true north, you'll make the right decisions in terms of your professional career and your private life. I describe myself as a humanitarian who happens to be a doctor.  I am an infectious disease specialist. The reason why I chose infectious disease, specifically tropical medicine, is because disease so is often associated with conditions of the poor. I feel physicians are the natural attorneys of the poor.  I describe my work as addressing the needs of the most vulnerable. 
When we look at infectious or communicable diseases, it is often the most vulnerable who are not necessarily going to get infected, but who will have the worst outcomes. This is not necessarily based on immunity, it is based upon several different factors, right? Like access to healthcare and access could be real or could be perceived. But the outcome is less health care availability. When it comes to something like COVID, which is unprecedented, or Ebola or TB, these communicable diseases have always existed. They have continued to exist in ways that are separated by space, not by time. 

For some reason, tuberculosis, malaria, even HIV are not necessarily relevant threats to many who grow up with privilege. Those people do not understand how to get connected to that or help with that. But the more our world is globalized,  the more that we understand that those spatial barriers are not as real as we think they are and a disease like COVID has clearly surpassed those, circumvented those barriers and boundaries and traveled across the world in record time. The youth need to understand that we are a part of a global community and that aspects like solidarity and social cohesion and support of the global community. The more that we focus on our differences the further we are going to be from maintaining some ultimate good for the world and to really understand how something like this is not just going to impact healthcare in the immediate sense, but is already causing ripple effects across the world in terms of food security, housing security, and mental health that we can't even begin to understand.

Sally Sacon:
 Thank you very much. I really appreciate it. I thank you for all you are doing and putting your life on the line in New York and taking the time to talk to us.

Dr. Tyler Evans:
 No problem.

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