Editor's note: Bruce Aylward, a Canadian epidemiologist and leader of the WHO-China Joint Mission on COVID-19, shares his insights with China Daily in Geneva on March 6.

What exactly does COVID-19 mean?

Coronavirus 2019. The aim is to let people know it's a new coronavirus and to differentiate it from those that caused SARS and other diseases like MERS.

What you want with a name is to clearly differentiate it from other diseases, and to clearly associate it with a certain symptom.

And when we name diseases like this we're very careful to try to avoid creating any kind of stigma and attaching it to a place or to a country or even a person. You want to foster global understanding and cooperation.

Let's talk about your experience in China. You were in the country for two weeks in early February. What was your impression when you arrived?

When I landed in Beijing what first struck me was this almost empty airport in a city of 20 million people. And it suddenly brought home to me the tremendous cost for the Chinese people, the Chinese economy. Driving from the airport to the city we saw the same thing. It took only minutes to reach the city, a trip that usually takes a lot longer. So I realized the impact of this.

During your visit were you afraid about contracting the virus?

No, because there are measures you can take to protect yourself and be safe. I washed my hands all the time and I wore a mask as requested by the government, public health officials and by people.

Then of course there was the matter of social distance. In our meeting rooms we stayed a meter or two away from each other. When we had lunch we either ate in our hotel rooms alone or we ate at separate tables, even at the Chinese Center for Disease Control and Prevention. We were also aware that we should be looking out for a fever and cough rather than a cold or a runny nose.

So we knew what we had to do. But we also made sure that in all of our travels, and I was in many, many places in China in those two weeks, that we never came in direct contact with patients. We never came in direct contact with the contacts of patients either. All we did was follow the wise measures the government, including public health officials, called for.

You mentioned wearing masks. Do you think they're needed to prevent this virus spreading?

They play an important role in preventing the spread of COVID-19. Patients obviously have to wear masks when they're in contact with people who don't have the virus, health workers have to wear masks, and of course, contacts too.

The question then becomes the general population. You always have to strike a balance between what difference these measures make and the cost and effect of wearing the masks, because you could have shortages that prevent them from getting into the hands of people who really need them. But people often say to me, "So was that a mistake in China with the masks?

And I say, "Well, look, we have never before in history put masks on 1.4 billion people and looked at the effect.

So this is something we have to study and learn from. It wasn't our recommendation, and China did some things differently. And, you know, China has turned around the outbreak and I would not quickly rule out anything that it did.

I think we have to study these things. But the really important thing was the speed with which you found cases and found contacts and took care of them.

Why did you decide to go to China in person? What did WHO want to find out in the country?

There were three big things we were interested in, and we're so grateful to President Xi Jinping for the invitation.

First we had to understand the severity of COIVID-19. How serious was it really, because you hear people saying, "Oh, it's like a mild flu" or "It's as bad as SARS" But what was it really? Because how severe the virus is drives everything in terms of the response.

The second thing that we had to understand was transmissibility. How does it transmit? Some diseases like flu transmit a lot in young children, but others transmit in other population groups. And getting out there to the provinces and talking to people managing the virus really helped us understand the main things driving transmission.

Because that then brings you to the third point we were interested in: whether the control measures work because China was using fundamental control measures to control a respiratory virus. These kinds of viruses move so fast that using case finding contact tracing won't work.

You need a vaccine or something else. And China proved through a disciplined, rigorous approach that you could actually turn it around with these measures. And we needed to study that and look at it to see what was really going on. So those were the three big things: severity, transmissibility and impact of control measures. They would help us in informing the rest of the world what was going on.

So let's talk about those one by one. First, how severe is it? What exactly is the difference between COVID-19 and the flu? Some people say it's just a strong flu, so we don't need to worry about that. Is that true?

No, this is a virus you have to worry about. It is not a flu virus, but a coronavirus. It will not mutate as fast as the flu virus and change its properties. And this virus has already told us it is a virus that can kill. It can kill many people, especially older people, people with comorbid diseases, as we call them, or other conditions. But it can also kill young people. People have to remember that. We understand that if people have conditions such as cardiovascular disease they're at a higher risk. But there are other things. And people don't understand why. And I spoke to a lot of doctors in China about this.

I said, "What do you really think is going on?" And they said that in the young ones they didn't quite know. And that's concerning, as well. So this is a virus that can kill between 1 percent and 4 percent of the people who get affected. That is a lot for a virus that can spread so easily. So you have to take this seriously. Flu, seasonal flu, is less than 1 percent. A fraction of 1 percent of the people who get it may die. This is an order of magnitude different.

How about control measures China has taken? What can the rest of the world learn from them?

Chinese public health officials kept on saying to me that there has to be a tailored approach to the kind of transmission you have, capacities and so on. So that was a big message we took away but the single biggest message I took away was speed. You have to find the cases quickly, and you have to get them isolated, and their close contacts need to go into quarantine if this thing is to be broken. So that was the first big message: speed, speed, speed.

The second was that you can't get speed without the cooperation of the population. The public have to understand the virus, understand how serious it is and understand how to get tested or get family or loved ones or colleagues tested if they think they have the virus. And China worked hard to remove barriers. Early in the outbreak the government said: "Look, when your insurance stops, the state will step in to cover the costs." That's important in helping people know that if they are tested positive it will not make them bankrupt. That's another important message for the West.

The government in China has done great things, but what really has impressed me is the people. There has been this sense of societal responsibility and of playing your part. Some people won't feel that way, but the overwhelming proportion do. It is a very, very special thing about China, and it really touched me.

Where do you think this sense of societal responsibility comes from?

I think there were two things working for China in this outbreak, one very recent and one very ancient. You have a culture that goes back centuries and aeons almost. And over time there's this wonderful sense of the importance of society has evolved in Chinese society and in much of the East, of course. It's quite different from the West, where individual rules and the society rules to a certain degree. Another thing is that since SARS you have really strengthened the public health capacities in the country. So that culture combined with the public health capacities can now be mobilized very, very rapidly. Add public health expertise, the people's understanding and strong leadership, and you have what it takes to beat something like COVID-19.

Some people say other countries have failed to take advantage of the window of opportunity that China's experience offered them. What do you think of that?

One of the things we say in our report is that China was a first line of defense against the worldwide spread of the virus. It eventually did spread out of China, of course, but then China very, very rapidly got control of the situation. And we did not see a further spread out of Wuhan or out of China to the rest of the world. The second line of defense became those countries infected next. One great thing was China's willingness to share its experience, share what it learned with the rest of the world. Our mission was allowed to look at whatever we wanted, and everything was very transparent. One point in our report, and this was before Italy, and Iran blew up in terms of cases, is that we were already seeing cases in South Korea, and we expressed our concern that the world was unprepared.

It was not learning the lesson from China quickly enough. We said that "You have to have your population with you, they have to know the seriousness of this, they have to be able to be rapidly tested." What we're seeing is some of the consequences when any part of that breaks down. But the other important thing we learned from China, and this is a message that I've been sharing with Iran and with Italy over the past few days, it is never too late to get this under control. It comes down to saving lives, saving lives, saving lives. Everything China has done has been about that

China created a window for the whole world to get ready and get ready fast.

Do you think they are ready?

No. We are seeing people still saying this may be like the flu, and we're seeing people taking measures that may not be quite what you would expect. And we're seeing countries that are surprised that they have to isolate 100 people. Well, your pandemic preparedness training should have taught you to do that. I try to be helpful and say "Certain parts of China had exactly the same problem, and here's how they tackled it.

What suggestions do you have for countries like Italy and Iran?

Educate your population really, really well about what the symptoms and signs are, and make it very easy to get tested, and as you get this under control in your own country do your role to prevent its international spread. Those are the big messages. The rest is technical stuff, but you need your population with you, which is what you have had in China.

Where do you think the novel coronavirus originated?

It's from nature.

This virus lived in animals and jumped across the animal-human interface. These things happen with different viruses. We've seen different diseases appear in all parts of the world. That's just the reality.

The fault lies in our relationship with nature. Our populations are growing and we're eroding the environment. We're doing this everywhere in the world. Climate change is moving forward. All of these factors are contributing to what we call these zoonotic diseases, and it won't stop. The important thing is that we work together to look for solutions. China's commitment to international solidarity in all of this is very important, because the next disease like this will appear somewhere else.

When do you expect this thing to be over?

We can't say whether there will be an end point. Another important thing I learned about in China was its pragmatic approach. It decided it was going to reduce its cases as close as possible to zero, then reopen schools and get people back to work and get its economy back on track. And it will be great if COVID-19 disappears, as SARS did. But they're not planning that way.

Every governor and every mayor I spoke to said: "We're buying ventilators and building additional beds, even though the number of cases is falling. Because if this continues to occur, we have to be able to live and work with it, find it fast, get it isolated, manage it, and in the meantime work on vaccines. And that's a very pragmatic and appropriate approach. I hope that like other viruses COVID-19 will disappear, but that's wishful thinking, and it's not good planning.

So how do we prepare for unknown viruses?

The most important thing is exactly what we learned. We've learned a lot from the early days of this outbreak already. And as your president said, we have to go back and look at that when all this is over to figure out how to reduce these jumps across the human animal barrier happening, and when they do to rapidly identify them.

In China an awful lot was done right in part because of the incredible science and expertise, including isolating the virus, developing diagnostics and so on. But in terms of global preparedness and information sharing there is still a lot to learn.

Are you afraid of what's happening outside China now, especially in Europe?

Anywhere where a new virus spreads rapidly in a population that doesn't have immunity, you have to be concerned to do everything possible to help put in place control measures to slow it down.