[Explanation] Recently, the University of Hong Kong confirmed that a patient who has recovered from new coronary pneumonia has been infected with the new coronavirus again after returning to Hong Kong from Europe. This is also the world's first case of secondary infection of the new coronavirus. On August 25, a reporter from China News Agency interviewed experts on this case.
[Explanation] According to Wu Zunyou, chief expert of epidemiology at the Chinese Center for Disease Control and Prevention, one of the important differences between secondary infections and the previous nucleic acid tests for Fuyang cases is whether they are infectious.
[Concurrent] Wu Zunyou, Chief Expert of Epidemiology, Chinese Center for Disease Control and Prevention
What Fuyang found was basically nucleic acid fragments, this is one. The second is that it has no live virus. After sampling from the biological sample, there should be no live virus in virus culture, and the patient has no symptoms and is not infectious. It is different for repeated infections. Repeated infections have several characteristics. The first one has a live virus, and he is infected with a live virus; the person who is repeatedly infected may infect other people; the person who is repeatedly infected may have symptoms.
[Explanation] Wu Zunyou believes that the main reason for the secondary infection is the attenuation of antibodies to the new coronavirus.
[Concurrent] Wu Zunyou, Chief Expert of Epidemiology, Chinese Center for Disease Control and Prevention
The protective effect produced by our people after being infected with the virus, not all the protective effects produced by infectious diseases are lifelong. The situation of the new coronavirus (virus), in fact, we have noticed this phenomenon a long time ago, and proposed this possibility. From the category of coronavirus, the antibody produced after human infection can last for a protective effect. , Which is 6-12 months.
[Explanation] Wu Zunyou emphasized that this case suggests that after being infected with the new coronary pneumonia virus, it does not mean that you have obtained lifelong immunity. Corresponding research should be conducted on this issue.
[Explanation] Li Bin, chairman of the Science Work Committee of the Chinese Society of Cell Biology, believes that memory immune cells in patients recovering from new coronary pneumonia may be able to help the body better fight the virus.
[Concurrent] Li Bin, Chairman of the Science Work Committee of the Chinese Society of Cell Biology
Your chances of developing severe and critical illness may decrease, because after all, we have some memory T cells against the new coronavirus in our body. Although these memory T cells cannot completely prevent infection, they may prevent your severe and critical illness. It might be good, we don't know this yet, because he is just an example.
[Explanation] In addition, the team of the Department of Microbiology of the University of Hong Kong confirmed that there are 24 differences in the genetic sequencing of the virus strains of this patient's first and second infections. In this regard, Li Bin pointed out that this phenomenon also inspires ongoing research on the new crown vaccine.
[Concurrent] Li Bin, Chairman of the Science Work Committee of the Chinese Society of Cell Biology
No matter how the virus mutates, it always has to enter the cell in order to infect the cell. The infection must bind (its receptor) ACE2. Most of the ACE2 vaccines focus on preventing it, or neutralizing antibodies (drugs). They all prevent the combination of ACE2, so I think the most optimistic situation is that the current vaccine may still be useful. If there are so many mutations that make the existing vaccines unusable, then we may choose a new epidemic strain next year, that is, the possibility of updating the vaccine to be updated is not a big problem.
[Explanation] Finally, Wu Zunyou said that it doesn't matter whether the virus mutation will bring about a second wave of large-scale epidemics.
[Concurrent] Wu Zunyou, Chief Expert of Epidemiology, Chinese Center for Disease Control and Prevention
The mutation of dozens of amino acids has no effect on the structural composition of the entire virus. The virus mutation is very small and will not affect it.
Wen Mengxin reports from Beijing
Editor in charge: [Ji Xiang]