Yanzhong Huang , a senior fellow for global health at the Council on Foreign Relations Photo: Courtesy of Yanzhong Huang

Editor's Note:

As the World Health Organization declared "Europe has now become the epicenter of the pandemic" of COVID-19 a few days ago, the UK government's chief science adviser, Sir Patrick Vallance released an astonishing strategy - aiming for 60 percent of the populace to get COVID-19 to build up some kind of herd immunity so "more people are immune to this disease" and to "reduce the transmission." 

The UK's strategy has been questioned since then. While UK Secretary of State for Health and Social Care Matt Hancock stressed on Sunday that achieving herd immunity to COVID-19 is not stated policy on Sunday, criticism of Vallance's avowed strategy persisted. 

Does the herd immunity strategy work amid the COVID-19 outbreak? Will it be a huge risk for countries that have taken strict prevention measures like China? 

The Global Times reporter Bai Yunyi (GT) interviewed Yanzhong Huang (Huang), a senior fellow for global health at the Council on Foreign Relations for a diagnostic of the UK's response to a global pandemic. 

How difficult to precisely control virus spreading?

GT: Is the herd immunity strategy feasible in the real world? Which key factors should be taken into consideration?

Huang: Herd immunity refers to allowing enough people to obtain immunity via vaccine or infection to stop the virus from further spreading and thereby protecting those vulnerable people with high risk of infection in the group. However, in the real world, a slew of conditions must be achieved before obtaining herd immunity, which contain many premises and risks.

First, the government that adopts the strategy must be able to isolate higher-risk and vulnerable groups, and make sure only low-risk groups which means healthy young people are part of the herd immunity effort. It is not easy to achieve.

Second, the virus should be stable without mutation. If the virus mutates, attacks the young group fiercely, and increases the number of severe cases and death rate, herd immunity will not work. The Spanish influenza that broke out a century ago caused severe damage among the youth and the death rate appeared in a "W" shape on the charts among people of various ages.

Third, to practice the strategy, the spread of novel coronavirus must be kept at a steady speed and no other epidemic broke out in parallel, and there must be enough medical resources to avoid overload. Otherwise, a lack of medical resources will impede the formation of herd immunity.

Therefore, I agree with some opinions that herd immunity is a wishful gamble.

GT: What are the risks to implement herd immunity strategy without a vaccine? Is it possible for a country to precisely control the related factors and risks?

Huang: Historically, most cases of herd immunity were attained through vaccines, and I have never heard about any country to roll out herd immunity intentionally without vaccines.

There are a lot of risks to implement herd immunity without vaccines. First, even though some 60 or 70 percent of people have obtained immunity against the virus through infection, the situation of a certain group in a certain region not obtaining herd immunity cannot be avoided, and once a person was infected, it will break out in the community very soon. It is possible to impose great pressure on medical system if the situation occurred in multiple places.

Second, according to the UK government, those who have infection symptoms should be quarantined at home to avoid spreading the virus to the high-risk group. However, it has been proven that some infected patients do not show any symptoms, which means that the virus will infect the vulnerable group inevitably.

The UK government also suggests reinforcing isolation and protection to seniors over 70, but I have no idea about how to make that happen as it is hard to completely isolate such a large population in a long term as six months.

Even in the nursing house, they have to be taken care of by the young people, who are able to have close contact with other people in society.

Lastly, the idea of herd immunity is to slow the virus' spreading speed and delay the pandemic peak, but the peak will come eventually. Many people still need to be treated in ICU for a long time during the peak. The UK currently has some 4,000 beds in ICU, and the possibility for overload of medical resources in the future could not be excluded.

What does it mean to other countries, including China and South Korea, once UK adopts herd immunity strategy?

GT: If the UK really promotes the herd immunity strategy, does it mean huge risks and uncertainty for countries, including China and South Korea, that have taken strict prevention measures?

Huang: It indeed will bring new challenges to these countries. Especially if more countries follow the UK or unconsciously follow it, China may need to maintain or even strengthen its strict control and prevention measures in the following months. Actually, preventing imported COVID-19 cases has become one of the biggest challenges for China. 

A worse situation is that once the novel coronavirus spreads in these countries, most of their populations will have gotten the immunity unlike the majority of disinfected Chinese. It will form "immunity gap" - like a barrier lake after an earthquake, once there is a breach or the situation is out of control, the virus, like the water will overwhelm the country. 

The situation is not unprecedented. At the beginning of the 16th Century, most of the adults in Europe had got immunity to the smallpox virus, while the indigenous peoples in the Americas did not. The smallpox virus brought by a few hundred European colonists to the continent killed 3 million of the native population. 

Under this circumstance, China must speed up the vaccine and anti-COVID-19 medical developments, make sure the majority of the population can get the vaccine as soon as possible, and also help other countries to control the epidemic. 

GT: Some scientists in the UK think COVID-19 will return next winter or next year, and that's why they rely on herd immunity strategy.

Huang: The flu which went viral globally in history did have the second and third rounds like the Spanish flu in 1918. But the situation may not be suitable for discussion of COVID-19. It is an assumption. 

Under this assumption, is herd immunity the only option? We can actually find out that even in the UK, its "delay strategy" is not the only way, and it is trying to find a balance point between offering the "maximum" protection to the people and the minimum destruction to managing society. It is stepping up efforts to cut social transmission and offer more tests, as well as centralizing the resources to take care of the critical patients. 

GT: What do you think about the ethic controversy over the herd immunity strategy?

Huang: In ideal conditions, everyone should receive good medical treatment, but it is hard to realize in reality. Even if the herd immunity strategy could be precisely implemented, there still will be sacrifices. Although the fatality rate among the young people is low, when it multiplies to a large number of population, there will be a high death toll. 

There is a more sensitive question, for example, when facing the choice between a young infected patient and an old patient - the former is creator of productivity, while the latter is user of social resources, so it can be seen as politically incorrect to choose to save the young. But it cannot be excluded that the policy-makers may have these considerations. 

Dealing with the epidemic is an issue of public health and also a political question 

GT: German Chancellor Angela Merkel has warned that up to 70 percent of the country's population - some 58 million people - could be infected. Some people think Germany shares similar thinking to dealing with COVID-19 with the UK. Do you agree? Are there any differences of the strategies among European countries?

Huang: Germany's strategy has some similarities with the UK and they both are based on one shared concept: the golden time to contain the virus has passed. But Germany has taken more active measures since it has completed and well-developed medical insurance system which allows more tests at the early stage and more timely treatments. 

But as we said before, since Germany shares the concept that it could not "contain" the virus, it now has taken more measures to "mitigate" the situation. 

Italy focuses on "containing" the virus, which is like China. But the senior citizens in Italy make up 23 percent of its whole population, which is higher than 18 percent in the UK and 21 percent on Germany. This means Italy is facing more pressure on its medical system and a higher fatality rate. 

Although Italy has declared to lock down the county, there are many loopholes. The current overload of Italy's medical system is very much like the situation in Wuhan in February. 

GT: Can you sum up the US strategy? How do you evaluate the US government's performance in dealing the epidemic?

Huang: The US, like many European countries, ignored the virus' risk and harm initially, failed to take active prevention measures and missed the golden window phase. 

US officials from the Centers for Disease Control and Prevention admitted a few days ago that the virus has spread, and it is hard to spot and treat every infected patient. So, they put forward to shift the strategy from containing the spread to mitigate the harm after the spread of the virus. The harm includes those to people's health as well as to the economy. That's why we see US President Donald Trump has tried to downplay the harm of the virus.

Trump has his own political consideration. How to deal with the outbreak is not only a public health issue but also a political question, whether it is in the US or in other countries. That is why Trump has faced a lot of criticism. The criticism pushed Trump to carry out some measures to contain the virus. 

One challenge the US faces is a low rate of medical insurance among the people, which makes many people reluctant to get testing due to the high cost. Now the problem on medical cost has been solved, but the capability to have large-scale tests lags behind. 

GT: China uses shelter hospitals to treat mild patients. Is this method necessary or possible for European countries and the US?

Huang: The purpose to build shelter hospitals is isolation, not treatment. Some mild patients can recover at home, but this will increase the risk of infections among family members, especially houses with small rooms. For most American families, they have a larger living room, which could help avoid cross infection among family members. The US does not have such high need for shelter hospitals.

As for possibility, a shelter hospital needs a large number of medical staff. It is a question for the US on whether it has the capability to mobilize so many resources from other places, like China. 

The background for Wuhan to build shelter hospitals was that the epidemic was severe but no large-scale transmissions have been found nationwide. The virus has spread to every state of the US and it is unrealistic to dispatch medical resources from one place to another.