China's top specialist in epidemiology and respiratory disease Zhong Nanshan said China will contain the latest surge of COVID-19 cases within a month. Dr. Zhong told this to CGTN anchor Liu Xin in Beijing with his research team to receive the National Science and Technology Progress Award, the nation's top honor on science and technology. How has his team contributed to respiratory disease prevention and treatment? Why does he believe China's zero covid strategy is cost-efficient and necessary? And when does he predict international travels to and from China to fully open? Below is a transcript of Liu Xin's interview with Zhong Nanshan.

Four things China has learned in dealing with the Delta variant

Liu Xin: There have been recurring COVID-19 outbreaks in different places throughout China. You recently said that although there have been small-scale clusters and sporadic cases in certain areas, it can be controlled very effectively in less than a month. What makes you say this?

Zhong Nanshan: When there is travel between China and the world, there will certainly be small-cluster infections caused by imported cases. Why do I believe such recurrence can be controlled within a month?

It's thanks to China's powerful prevention and control measures. We've examined our experiences in coping with previous small-scale clusters, the earliest one occurring on May 21st in communities in Guangzhou. It turned out to be the Delta variant.

After that, the virus also emerged in Nanjing. We've been able to learn from these experiences.  There are a few key questions.

The first is to find out where "patient zero" is from. Secondly, we have to establish the chain of infection, which is also a very important aspect. The third is to find the close contacts of the infected by following the chain of infection, so that targeted screening can be carried out. Fourthly, if there are many confirmed cases in some places, all people there will need to be tested and quarantined quickly.

Based on these experiences, the outbreak in Guangzhou was under control within 30 days, while a similar outbreak in Nanjing also subsided in 24 to 26 days.

If the above measures are tested and proved effective, I believe the recent outbreaks in China's northwest region, and in Heilongjiang Province, will also be controlled within a similar period of time.

In other parts of the world, when there are sporadic cases, it often lasts for several months, which may cause a huge impact on society. But I'm confident that China can solve the problem within a month. This is my opinion. 

Is China's COVID prevention policy too costly?

Liu Xin: China's "zero-tolerance" policy on the pandemic is considered too costly by some foreign commentators. Even some people in China may feel that the cost is too high and not worth it to be followed elsewhere. What do you think of China's pandemic prevention and control policy?  How sustainable is it?

Zhong Nanshan: The "zero-tolerance" or "zero-transmission" strategy is a last resort because the virus spreads too quickly and its reproduction rate is too high. It seems that despite the vaccines, the death rate is still about 2% worldwide, a level still too high to be tolerated.

It's true that the current cost of adopting a "zero-transmission" policy is indeed high. But it would cost even more if we live with it and open up. Now, there are some countries, despite low levels of transmission, that have decided to lift all restrictions and live with the virus.

Over the last two months, as there has been a surge of new cases, many of those countries have started to tighten the restrictions again. In fact, such pendulum moves would result in even greater costs.

It deals heavy psychological blows to the residents and society as well. That's why China has adopted a gradual approach to lift control measures.

But now, the overall policy is still "zero tolerance." I call it "persistent zero infection and transmission," rather than "absolute zero infection."

It means that as soon as an outbreak appears, the measures I talked about can be used to reduce its impact to a very low level. Eventually, the flare-ups will be put out.

China will still stick to the "zero-infection" policy for a rather long time. As for how long it will last, it really depends on how other countries perform in controlling the virus.

Even if China is doing a good job, as long as it opens to the rest of the world, there will certainly be imported cases. So, I think the current "zero-transmission" strategy is not too costly.

Instead, it's a relatively low-cost approach under the current circumstances. 

The effectiveness of booster shots

Liu Xin: Now there is a question about time. Currently, many places in China have already rolled out the booster doses, but a long time has passed since many people received their first two shots. Will the long interval affect the effectiveness of the booster shots?

Zhong Nanshan: Till now, there is no rigorous experimental observation or prospective research for this question.

Generally speaking, in the case of Chinese vaccines, the antibody titer blood test results show a decrease in antibodies after 3 months.

The decrease is more obvious 6 months after vaccination. Some people had their second shot 10 months ago. But from our clinical observations, despite the long intervals, the booster shot still works well in raising the antibodies significantly.

It's common to see the antibodies increased by 5 to 10 times. So, the long intervals should not be a big issue. After getting vaccinated, in addition to humoral immunity, we also acquire cellular immunity, meaning the lymphocytes which kill the virus can remember the antigen.

When a booster shot is administered, it can evoke the cellular memory and stimulate the cell to release a great number of antibodies. So, in this case, timing shouldn't matter that much.

How far are we from herd immunity?

Liu Xin: You just talked about the threshold of 80% vaccination rate for reaching herd immunity. So, does it mean that 80% of people must receive the booster shot before the whole society is safe? And how long will it take to reach such a goal, since there are 1.4 billion people in China?

Zhong Nanshan: Until now, more than 1 billion people in China have received two shots, that is, the full-dose. And the booster shots are being rolled out.

Ideally, booster shots would make it safer, and give better protection. By the end of this year, about 80% of all Chinese people are expected to get the full-dose. We can undertake the administration of booster shots during the first half of next year.

By that time, there's a greater chance that we can have a robust herd immunity. It should be noted that in China, even many children have been vaccinated; more than 90 percent have been vaccinated. The vaccination rate for the 17 to 59-year-old age group has reached over 80%.

But we have to note that the vaccination rate among seniors over 60 years old is still not enough. Yet, they are the most vulnerable to Delta because they often have complications.

They are more likely to become critically ill when infected. Therefore, it's imperative to ramp up their vaccinations. I estimate that when the majority of residents in China get booster shots by the first half of next year, public health will be more assured.

The problem now lies with vaccine supply. China not only needs to provide for its own people to ensure the public can be fully protected; it also needs to fulfill its commitment to the whole world.

So, we are looking forward to a higher volume of vaccine production, not only for China, but also for the international community.

When can we see policy change in China?

Liu Xin: But how long do you think such a policy will last? As you said earlier, as long as there are still viruses spreading in other parts of the world, it is unlikely that China will take the freewheeling approach of the West or some other countries by lifting the restrictions. So how long it will be before we see some change?

Zhong Nanshan: I don't think it will take too long. Why? An important factor is that vaccines are becoming more available. If the WHO's COVAX scheme can be rolled out gradually, more and more people will get vaccinated in developing countries. The vaccination rate will then pass the critical point and eventually make a difference.

Take China as an example. In light of the protection rates of Chinese vaccines, when 80% of the population receive full doses plus some booster shots, the rate of infection and its seriousness will be significantly reduced.

If countries could vaccinate as many people as possible, the chance of fully opening up will be higher. Another factor is that the mutation of the virus seems to have slowed for now. Most of what we see is the Delta variant.

The recent cluster infections in China's northwest, and in Heilongjiang Province, have all been caused by the Delta variant. We have some methods to deal with the Delta variant. Vaccines can be effective in protecting us against it.

Under such circumstances, if countries could run extensive vaccination campaigns to get their people vaccinated, then the mortality rate will decrease further. Of course, in absolute terms, we hope that the mortality rate can be reduced to a level similar to that of influenza.

The mortality rate is 0.5% for influenza, in general. That is 0.5% for seasonal flu, which is more severe than normal flu. So, from 0.1% to as high as 0.5%. But the mortality rate for COVID-19 remains at 2% worldwide.

Vaccination and prevention and control at the community level are needed in order to reduce the virus infection, mutation, and mortality rates.

When the mortality rate is reduced to a level similar to that of the flu, then we may be able to live with it. Then the occasional emergence of the virus can be tolerated.

Liu Xin: When do you expect Chinese people to be allowed to make relatively more frequent international travels with the help of a vaccine certificate?

Zhong Nanshan: Again, this depends on the joint efforts of the whole world. I think we can achieve that step by step. For those countries with high rates of full-dose vaccination, we may open faster and sooner.

For those lagging behind, we will move in phases. Roughly speaking, I think around the end of next year we should see some changes.

Winning China's top science award

Liu Xin: Your team was just awarded with the first prize of the State Science and Technology Progress Award, which is the highest award conferred by the Chinese government in science and technology. Congratulations. What does winning this award mean to you?

Zhong Nanshan: I think this is a very important recognition of our team's work, which also acknowledges the direction that we have been heading.

Targeting common diseases, frequently-occurring diseases, and public health emergencies, our team's focus is early detection, early diagnosis, early quarantine, and early treatment.

We have always been committed to this direction, whether it is the sudden outbreak of infectious diseases or the spread of chronic diseases. So, in a sense, this award represents a great recognition of our efforts.

Liu Xin: Specifically, as this is a science and technology progress award, what is the message the award is sending to scientists and researchers around China?

Zhong Nanshan: Firstly, our research work should be based on the urgent needs of the country. This is what the country needs most. This is a very important message.

Secondly, since we work on medical diagnosis, treatment and rescue, it is necessary that we deal with it from the early stage. China's overall strategy in medical care is centered on safeguarding people's health, instead of treatment.

In other words, whether it is to address a new public health emergency or the spread of all chronic diseases, the key is early detection, early diagnosis, early quarantine, and early treatment.

This is true for both acute diseases and chronic diseases. This is a very specific as well as a very strategic requirement. This principle has been demonstrated in many areas that we have seen.

Global cooperation in fighting COVID-19

Liu Xin: What do you think is the biggest difficulty facing global cooperation in the fight against the pandemic? There have been a lot of controversies concerning the pandemic, especially about tracking down the origins of the virus. What is the most important lesson that the scientific community should learn?

Zhong Nanshan: The biggest problem with tracing the origins is that it's become politicized. We used to have some cooperation with the U.S. and some other countries, especially in tracing the origins. We could have all benefitted from each other's strengths. 

But once we began discussing the issue, some people focused on accountability, to investigate which country or which place was responsible for unleashing it. 

Politicization is the biggest obstacle. When it comes to vaccination, our cooperation is still insufficient. There's not much collaboration. Some countries are doing well. But for others, such as Russia, which has done a good job, there's little recognition. Chinese shots including Sinopharm, Sinovac, etc., were only recently recognized. There is a lack of communication, partly also due to political reasons.  

There should have been very good communication and exchanges. We should have a common guideline like in climate change and carbon neutrality. This is especially true for big countries.

When vaccines are developed, should it be a public good or a profit-making tool? Or even a tool to manipulate policies? I think this is the biggest, and the only obstacle. 

Scientists view vaccines as benefitting the whole world. To make the shots – and even make some drugs widely available to all – is the common desire of many scientists and some companies. 

But mixed with political factors, it gets complicated. This is the challenge. Otherwise, vaccines could have provided greater support for developing countries. So, we have a common task, but fret with obstacles. 

I believe and I hope that in the future, under the organization of the WHO, for instance, there will be better cooperation to make vaccines, some effective drugs, and some therapeutic antibodies into public property. 

In this way, we'll be able to effectively control the spread of COVID-19 throughout the world in a short period of time.