Zhong Nanshan’s 12 latest judgments on the epidemic contain a lot of information!

Can we take off our masks now? Are asymptomatic infected people contagious? Can the virus be transmitted between animals? When will the turning point of the global epidemic come? With these questions, a reporter from People's Daily went to Guangzhou and interviewed Zhong Nanshan, an academician of the Chinese Academy of Engineering and a respiratory disease expert.

1. Now is not the time to take off the mask

It is not the time to take off the mask yet. The situation at home and abroad is very different. China has entered the second stage of the epidemic due to its decisive measures, while some other major countries are still in the first stage of the outbreak and are still climbing. This means that the probability of human-to-human transmission is very high and the number of confirmed cases is increasing very fast. Wearing a mask is still an important means of self-protection. It is too early to say that you should not wear it now. However, in areas where the epidemic is not serious, places with few people or open places, it is not necessarily necessary to wear a mask.

2. Wuhan has passed the test, but there is still another test

I am also very happy that Wuhan has been unsealed. When the epidemic broke out, the central government acted decisively to control Wuhan's urban traffic, and other places adopted group prevention and control measures, which were very successful. In the history of epidemic prevention and control, this can also be called a feat.

There are still two challenges ahead. One is how to resume work while preventing and controlling the epidemic, and the other is to prevent the import of the virus. The epidemic is still at its peak overseas, and some large coastal cities in China that have close exchanges with foreign countries are likely to be involved and some outbreaks will occur, and they still need to pass various prevention and control measures.

3. The possibility of a second outbreak of the epidemic in China due to imported cases is small

Will the continuous emergence of imported cases from abroad lead to community transmission and trigger a second outbreak of the epidemic in our country?

There are actually two questions: one is whether the imported cases have spread, and the other is whether there will be an outbreak during the spread. There is definitely a risk of transmission from imported cases, especially those with positive nucleic acid tests or symptoms of infection, which are highly contagious and can cause the virus to spread.

Will it cause an outbreak? It is estimated that the possibility is relatively small. my country's group prevention and control has been extended to the community, and community residents have a strong sense of self-protection, such as wearing masks and keeping a distance from others. Once someone has symptoms such as fever, they can quickly report or receive diagnosis and then be isolated. Overall, the risk of community transmission is definitely there, but the probability of a second major outbreak in China is very small.

4. It is too early to talk about the turning point of the global epidemic

From a global perspective, the original epicenter of the epidemic was in Europe, especially Spain and Italy, and now also in Germany, France, and the United Kingdom. The United States is currently facing the biggest problem, with an increase of 10,000 to 20,000 cases per day in the past week. Therefore, it is too early to see a turning point now.

Whether or not we reach the turning point depends on whether the government can intervene strongly. There are many unpredictable factors in other countries, so it is much more difficult for me to predict the global turning point than to predict China. If the current situation continues, it may take another two weeks.

5. The proportion of asymptomatic infections in China will not be large

Asymptomatic infections do not appear out of thin air. They usually appear in two groups: one is people in areas where the epidemic is relatively serious, who have not yet shown symptoms but may have been infected. The other is close contacts of confirmed cases. They account for a relatively small proportion.

There are two concepts of asymptomatic infection. One is that there are no symptoms at the beginning, but they will gradually develop symptoms later. This type is definitely contagious. The other type is what we recently discovered. During a long period of observation, there were no symptoms, but the nucleic acid test was positive. We are studying the infectiousness of this type. However, according to the characteristics of the new coronavirus, once symptoms appear, the infectiousness is relatively strong, so it is the right strategy to isolate and observe them as a group.

6. Most patients who have tested positive again are not contagious

The so-called "re-positive" should mostly be nucleic acid fragments rather than the virus itself. Two situations need to be noted. The first is whether the patient himself has relapsed. If the patient produces strong antibodies, he will generally not be infected again. As for whether the re-positive patient will infect others, specific analysis is required. Generally speaking, nucleic acid fragments are not contagious. Some scholars have cultured the throat swabs and secretions of re-positive patients and did not culture the virus.

There is also a rare situation where the patient already has many underlying diseases, but the symptoms have improved and they have not fully recovered. These patients cannot be ruled out as being contagious.

Overall, I am personally not too worried about whether patients who have tested positive again are contagious.

7. There is no sufficient evidence that COVID-19 is influenza-like

Will the new coronavirus persist for a long time like the flu?

This is a view of one school. So far, there is not enough evidence. Unless the virus spreads in a pattern: its infectiousness is still strong, but the mortality rate is getting lower and lower, in this case, it is possible to exist for a long time. We now need to conduct a long-term observation and master sufficient data and cases to come to such a view. Under the current circumstances, I don’t think this prediction will be realistic.

8. It is too early to draw conclusions about animal-to-animal transmission

Dogs, cats, tigers and other animals tested positive for nucleic acid. Whether it was caused by pollution or infection remains to be seen. Some animals already carry some viruses, which may not show symptoms and may not be contagious. It is too early to conclude that the new coronavirus in these animals can infect both humans and animals and cause disease. Generally speaking, I don’t think so.

9. There is no specific cure, but some effective drugs have been found

Some of the drugs we are testing now, such as chloroquine, have definitely shown effective results. We are summarizing the results and may publish them soon. There are also some traditional Chinese medicines, such as Lianhua Qingwen. We not only conducted in vitro experiments, but also found in the P3 laboratory (i.e., biosafety level 3 laboratory, editor's note) that it has a weak antiviral effect, but outstanding anti-inflammatory performance. The relevant experimental results will be published soon. In addition, there is the traditional Chinese medicine Xuebijing, whose main ingredients include safflower, salvia miltiorrhiza, red peony root, etc., which are used to promote blood circulation and remove blood stasis. It is also effective in the treatment of critically ill patients. We are also summarizing the results now.

10. Vaccines won’t be available soon

To truly end the epidemic, vaccines are very important. Now all countries are developing them at the fastest speed. But I don’t think a vaccine can be made in three or four months. In addition, based on the experience of fighting SARS, removing the intermediate host can also block the spread of the epidemic. At present, we don’t know what the transmission chain of the new coronavirus is like, and it is also important to cut it off after figuring it out.

Putting all hope on vaccines and ignoring other methods is passive. Moreover, after the vaccine is released, it is impossible for it to be perfect all at once. The susceptible population can be vaccinated, but it is not necessary for everyone to be vaccinated.

11. Herd immunity is the most passive approach

The most passive approach to the epidemic is the so-called herd immunity, which was an idea more than a hundred years ago. At that time, humans had no choice but to let the virus infect them, and those who survived the infection naturally acquired antibodies. I don't agree with using this method to deal with the new coronavirus now. In the past hundred years, humans have made great progress and have many ways to prevent it. There is no need to use natural immunity or herd immunity.

12. The most worthwhile experience in China’s fight against the epidemic is execution.

China has taken two major measures to fight the epidemic: one is to block the outbreak area and prevent the spread of the disease; the other is to prevent and control the disease at the grassroots level. Now the core of prevention and control is also two: the first is to keep distance, and the second is to wear a mask.

Therefore, the most shareable experience is execution. The medical level and technical strength of many countries are much higher than that of my country. The reason why they were caught off guard in the face of the epidemic is that they were not mentally prepared and did not take corresponding measures decisively, resulting in many frontline medical staff being infected. Once this line of defense collapses, it will be easy to get out of control.