What WHO advisor David Heymann told us about COVID-19

In conversation with World Health Organization (WHO) expert advisor Prof. David Heymann, Medical News Today heard about his past experiences with SARS and MERS, what individuals can do to stop the spread of the new coronavirus, and how long he expects the pandemic to last.

WHO advisor Prof. David Heymann spoke to Medical News Today about the COVID-19 pandemic.

In response to the COVID-19 pandemic, expert advisors are urging countries to take measures to slow down the spread of the infection.

One of these experts is Prof. David Heymann from the London School of Hygiene & Tropical Medicine in the United Kingdom.

An infectious disease specialist, Prof. Heymann’s career has seen him working across the globe on Ebola, polio, smallpox, and a host of other infectious diseases. He is also no stranger to coronaviruses.

Medical News Today spoke to Prof. Heymann about the lessons experts have learned from past coronavirus outbreaks, what people need to know about the current pandemic, and what it really means to have a mild case of COVID-19.

‘Western countries are doing less well’

MNT: What were your roles during previous coronavirus health emergencies?

Prof. David Heymann: When SARS occurred, I was the executive director of the communicable diseases program at the WHO. In that capacity, I led the global response to the outbreak.

For the MERS coronavirus outbreak, I was working with Public Health England as the chairman of their advisory board, and I participated in two different missions to Saudi Arabia for outbreaks of MERS coronavirus.

And during this outbreak, I am chairing a group at WHO called the STAG-IH — the Scientific, Technical Advisory Group for Infectious Hazards. We are the group that supports the WHO in its risk assessment for infectious disease outbreaks. We just finished a meeting today looking at what’s going on in the world and talking with Executive Director of the Emergencies Program Mike Ryan about what we would suggest be done in the next few weeks.

“So in Italy, for example, we’re seeing people die because they can’t access hospitals because there is not sufficient surge capacity. Hopefully, that same thing won’t happen in other European countries.”

MNT: Do you feel that the lessons learned during SARS and MERS, as well as Ebola, have helped prepare the world sufficiently to respond to the current pandemic?

Prof. David Heymann: Well, it certainly has prepared countries in Asia. Singapore, Hong Kong, Taiwan, and South Korea are doing quite an impressive job in getting the outbreaks under control in their countries by making sure that they don’t have a surge of patients to hospitals and ensuring that they have a very low case fatality ratio.

Western countries are doing less well. Except for Canada, they didn’t have SARS or MERS outbreaks, and they didn’t heed the warnings to take the necessary preparedness measures.

And though many of them had exercises and activities to prepare them, what they haven’t done is built the capacity to deal with a surge of patients who require ventilation. So in Italy, for example, we’re seeing people die because they can’t access hospitals because there is not sufficient surge capacity. Hopefully, that same thing won’t happen in other European countries.

MNT: How challenging is it for people like yourself, but also governments who come up with public health recommendations and strategies, to work during a pandemic?

Prof. David Heymann: It’s very easy for individual countries to make recommendations based on national risk assessment, and they are able to obtain much of the evidence required from materials in the public domain. What is less easy is for the WHO to convince countries to have a more uniform response.

And so each country has a different response to this outbreak, based on their own risk assessment and the capacities that they have to deal with outbreaks.

The jury is still out’

MNT: Do you feel that with the information that governments are giving out and the WHO are publishing on different forums every day, the general public has a good understanding of the implications of the pandemic? Or is this something that you wish people would take more notice of?

Prof. David Heymann: People need to understand that they can prevent themselves from getting infected by washing hands and by maintaining a physical distance from each other and that they can protect others by wearing a mask if they’re coughing and sneezing.

They can also prevent others from becoming infected if they don’t cough or sneeze directly on them. The effectiveness depends on how well a country can get its population to understand these measures and contribute to the response.

If you’re looking at what governments can do, they should be identifying all cases if they can, and trying to trace where those cases come from and the contacts that they have had, so that they can stop outbreaks by rapidly identifying new cases and making sure they’re isolated.

MNT: Do you think it would be good if all countries were testing all suspected cases, and what are the practicalities of doing that?

Prof. David Heymann: Well, again, it depends on what a country is able to afford to do. Countries that have discrete outbreaks can learn a lot by investigating them and by doing contact tracing, monitoring of contacts, and isolating those who are or become ill.

One problem in trying to understand outbreaks and transmission patterns completely is the lack of a validated antibody test that can determine who has been infected in the past. And because of this and the fact that people who may have been infected may have had minor symptoms, it is very difficult to understand where infections came from.

But testing using PCR [polymerase chain reaction], which is a reliable indication of current infection, is important to identify where cases are and get them isolated.

MNT: Do you think that countries like the U.K., the U.S., and other countries in Europe are doing the right thing, or could they be doing more?

Prof. David Heymann: The jury is still out on what effect activities in the U.K., and in all other countries, are having. Most countries were not prepared enough, and now they are attempting to delay the surge of very sick people who come into hospitals.

MNT: Do you foresee that restrictions will get tougher to prevent this surge of people overrunning healthcare systems that didn’t have time to prepare and didn’t heed the warning signs?

Prof. David Heymann: I can’t tell you. I don’t know. This is a political decision.

MNT: Do you think it makes sense for restrictions to become tougher?

Prof. David Heymann: I don’t know. Each country is going to do what it feels it has to do based on its national risk assessment.

Certain severe measures in China have been very effective in curtailing outbreaks in China. But now, the question is: What happens when they release those severe measures? Will there be a second wave of infection? Nobody is able to predict this with certainty.

MNT: Do you think that it is realistic to look to a vaccine as the answer to slowing and stopping the pandemic in the long term?

Prof. David Heymann: The question is: Will there be an effective vaccine, and, if so, when will it be licensed? Many experts say in 18 months or so. But then, will there be the production capacity to produce the vaccine in sufficient quantities?

And finally, access to that vaccine may depend on where you live. If you live in the U.K., you might have a better chance of accessing that vaccine than if you live in Africa or parts of Asia.

As a comparison, the maximum capacity for producing a pandemic influenza vaccine is estimated at approximately 2 billion doses, and that is in a world of over 7 billion [people].

Mild cases, outlook, and climate change

MNT: Many health authorities report that about 80% of people who have the disease experience mild symptoms. For many people, this will imply that it will feel akin to a common cold. But actually, looking at the guidelines for healthcare professional staff that WHO have produced, there is quite a lot more to the severity of symptoms. How rotten might people expect to feel while their experience is medically classed as a mild case?

Prof. David Heymann: Mild illness resembles influenza, with muscle aches, pain, headaches, fever, just feeling bad for a few days, coughing — of course — and then recovering.

Those who do not recover and become progressively shorter of breath require hospitalization and, depending on the age and any existing comorbidities, may not recover, with illness ending in death.

MNT: Do you think there is an end in sight? Is there a prediction of when this pandemic might be over?

Prof. David Heymann: You know, with all new and emerging infections, what’s unknown is what the outcome will finally be — the final destiny of the infection. HIV emerged in the early 20th century and then became endemic throughout the world.

Seasonal influenza has emerged from the animal kingdom, and there are currently three endemic seasonal influenza viruses carried by humans.

And there are many other diseases that are endemic, like tuberculosis, that are also thought to have come from the animal kingdom.

The question is: Will this new coronavirus become endemic like those infections, or will it be more like Ebola, which can be contained when an outbreak occurs, only to reappear at some future time? No one can predict with certainty the destiny of this virus.

“Mild illness resembles influenza, with muscle aches, pain, headaches, fever, just feeling bad for a few days, coughing — of course — and then recovering. Those who do not recover and become progressively shorter of breath require hospitalization and, depending on the age and any existing comorbidities, may not recover, with illness ending in death.”

MNT: Do you think that climate change and global population increases in general increase the likelihood of seeing more pandemics in the future?

Prof. David Heymann: We’re seeing an increase in outbreaks and pandemics caused by emerging infectious agents for many reasons.

First, people are living closer to each other and closer to the animals they use for food, creating a situation where infectious agents can more easily cross the species barrier between animals and humans and then transmit more easily between humans.

Climate change certainly plays a role in this. One way, for example, is by damaging our environment so that people are forced to leave arid lands they once farmed for work in urban areas where they add to urban crowding and demand for food, some of it from animals they purchase at markets.

And then there are globalization and rapid travel, which also play a role. In the past, coronaviruses that cause the common cold in humans also emerged, possibly in the same way as did the current pandemic.

But they did not have the opportunity to hop on international flights and spread rapidly around the globe. They likely circulated locally and then gradually spread to neighboring countries and onward throughout the world.

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