After China took decisive measures, the epidemic in the country has now entered its second phase, said Zhong Nanshan, China's renowned respiratory expert, Academician of Chinese Academy of Engineering, in an interview with People's Daily.
However, he noted that some countries are still in the first phase of the outbreak and the situation continues to escalate, which also means there is a high possibility of human-to-human transmission with rapidly growing numbers of confirmed cases.
"It's not time to take off the masks, which is still an important measure for self-protection," he said.
Zhong noted that China now faces two major tests, the first being how to gradually resume production while maintaining prevention and control work, and the other is fending off risks of imported infections.
The risk of community transmission caused by imported cases certainly exists, but the possibility of outbreaks is relatively small, and given the enhanced public awareness of self-protection, a second wave of outbreak in China is unlikely, Zhong said.
"China's prevention and work has been deployed at communities. Residents now have a strong sense of self-protection. Once there are people with fevers, they can be rapidly reported, diagnosed and isolated," Zhong said, noting that the risks of community transmission definitely exist, but the chances of a second wave are very small.
It's too early to talk about an inflection point in the global coronavirus pandemic, and the biggest problem is the US, given its rapid growth in case numbers of 10,000 to 20,000 per day this week, Zhong said on Sunday, noting that there are unpredictable factors in projecting this point now, and it might take two more weeks to start making that projection.
China does not have a large proportion of asymptomatic patients, and most recovered COVID-19 patients will not infect others, Zhong said .
Asymptomatic patients usually exist in two groups: people from areas where the virus is rife who have not yet shown symptoms after being infected; and those who have had close contact with confirmed cases, said Zhong.
He stressed that the proportion of those patients is relatively small.
Some asymptomatic patients may show an onset of symptoms later, said Zhong, noting that this group of patients are infectious.
Zhong said he and his team are researching the infectiousness of the second group of virus carriers, noting that based on the virus' particularity, once symptoms show, this group of people possess a strong ability to infect.
The second group of people are now being put under quarantine and observation.
Zhong also said concerns that recovered patients may be infectious do not worry him.
"The so-called 'recovered patients who test positive again' mainly refer to the fact that they tested positive again for nucleic fragments, not that they were invaded again by the virus," Zhong said.
He said attention must be paid to whether the virus invades recovered patients again. If patients already develop strong antibodies inside them, normally they won't become infectious.
Normally, the virus's nucleic fragments are not infectious, said Zhong, noting that scholars cultivated throat swabs from recovered patients and found no virus in them, according to Zhong.
In rare situations, patients who already have underlying diseases only see an improvement in their symptoms but do not recover completely. Zhong said this group of patients are, in fact, infectious.
这是一派的观点。到现在来看，还没有充足证据。除非病毒传播出现这样的规律：它的传染力仍然较强，但病死率(case fatality rate)越来越低，在这种情况下，有长期存在的可能。我们现在需要进行一个长期的观察，掌握充分的数据、案例，才能够得出类似这样的看法。在现在的情况下，我不认为这种预测会是现实。
狗、猫、老虎等一些动物核酸检测（nucleic acid testing）阳性（positive），究竟是污染造成的，还是感染的，有待观察。有些动物身上原本就带有一些病毒，不一定有症状，也不一定会传染。
There are no specific medicines for coronavirus, although some have turned out to be effective in treating it.
Zhong said his team is testing the effectiveness of medicines such as chloroquine and traditional Chinese medicine (TCM) formulae such as Lianhuaqingwen and Xuebijing, which have been proved to be effective in treating critically ill patients.
Zhong believed that a vaccine will not be available in the near future and placing all hopes on a vaccine while disregarding other methods is a negative approach.
"I don't think the vaccine will be available in three or four months," he said. "After the vaccine comes out, you can't expect it to be perfect. Highly infective people can get vaccinated, but it is not necessary for everyone to be vaccinated," he said.
He also noted that it is important to identify the intermediate host of the coronavirus.
"Based on our experience of fighting SARS, removing the intermediate host can also curb the epidemic. At present, we do not know the whole chain of how the novel coronavirus spreads. It is also important to cut the intermediate host off after figuring it out," he said.
Regarding the "herd immunity" approach, Zhong said this is the most passive way of fighting the epidemic.
"This idea goes back a hundred years when humans had no choice but to let the virus infect them so that those who survived it naturally obtained antibodies. Now, there are many precautionary methods and there is no need to adopt 'herd immunity,'" he said.
Zhong believes the experience most worthy of sharing in China's success over coronavirus is its strong enforcement ability, especially in locking down the worst-affected areas to block the spread and popularizing precautionary measures among individuals.
"Some countries are more advanced than China in terms of medical treatment and technical strength. However, they were not well prepared and did not take immediate measures, which led to the infection of frontline medical staff. When this defense broke down, things quickly went out of control," he said.
㊣ 本文永久链接： 可以摘口罩了吗？新冠肺炎会流感化吗？全球拐点到了吗？钟南山最新判断！