Zhong Ming: Some people say that positive infected people will produce antibodies only after a week of recovery, which is not accurate

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On December 25, Zhong Ming, Director of the Department of Critical Care Medicine at Zhongshan Hospital of Fudan University, was a guest at the Shanghai Science and Technology Forum, explaining the issues related to the new coronavirus and answering questions of public concern.

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Recently, it has been said that antibodies will be produced only after a week of recovery for positive infected patients, so there is a concern that they are prone to secondary infection during this week. Zhong Ming said that this statement is not accurate.

Zhong Ming said that antibodies appear on the 7th day of infection, and start to rise on the 14th day, reaching a high peak on the 21st day. In addition, the rise in antibodies is basically the reverse of the fall in antigen and nucleic acid. The reason why an infected person’s body is able to clear out the virus is because the immune system works to clear out the virus, which is accompanied by the production of antibodies. In other words, recovery must have antibody production.

“It’s not accurate to say that there are antibodies only after a week of recovery.” Zhong Ming said, just in the recovery of a period of time, the antibody concentration will also rise, the protection will also be stronger, “people do not need to worry too much, you recover, the body has a certain immunity and resistance to this virus, do not need to worry too much about secondary infection.”

Serious illness has always been the public’s greatest concern about the situation, how to determine the tendency to have serious illness? Zhong Ming said the more serious cases are those where the virus invades the lungs. People have been saying “new crown pneumonia”, now the Omicron strain many times can not be called new crown pneumonia, there are few people with pneumonia. “What is meant by pneumonia is that there is inflammation in the lungs and you see a lot of hairy glass-like exudate when you do a CT.” Zhong said Omicron is still similar to a cold most of the time, attacking the upper respiratory system, and if it goes to the lungs, there may be symptoms of respiratory distress.

The most common tendency to develop severe symptoms, he said, is shortness of breath and chest tightness. Experts often talk about home monitoring, and what to monitor includes shortness of breath and chest tightness symptoms. A common cold is a symptom of the upper respiratory tract, and a person will not have shortness of breath or chest tightness. “Imagine climbing four flights of stairs when you are physically fit, and you will have a feeling of shortness of breath. When you don’t move on a flat surface, you also have this feeling, which is pathological chest tightness and shortness of breath, which may mean that (the virus) is going to the lungs, which may be pneumonia, and then the symptoms are more serious, and you need to go to the hospital in time.” Zhong Ming said.

So, does a positive nucleic acid mean it’s still contagious? Zhong Ming said, the body can excrete live virus, indicating that there is contagious, but positive nucleic acid does not necessarily mean that there is contagious. Studies have shown that on average, 7-9 days after infection, Omicron no longer excretes live virus and is not infectious. This time is more consistent with the time of antigen positivity, and more consistent with the time when the infected person has symptoms.

In other words, the infection is basically not contagious about a week after infection, or after the antigen turns negative. But after a week or so, the nucleic acid level is still very high, and the nucleic acid test is still positive at this time, and will remain positive for some time.

Zhong emphasized the importance of vaccination, which allows the body to produce antibodies against the virus in advance, giving a person some resistance to the disease, and the probability of developing a serious illness is lower after vaccination.

The data show that for vulnerable people, the risk of death is about 14.7 percent if none of the vaccines are administered, dropping to 7.16 percent after one dose of the vaccine, and to 1.5 percent if three doses are administered, a tenth of the original risk. “So vaccination is a very important thing for the elderly and vulnerable people.” Zhong Ming said.

In the past three years of the new crown epidemic, Zhong Ming has often been on the front line of treating critically ill patients, but people like him who deal with the new crown virus almost every day have never been infected with it. He thinks he usually he does two things well, one is to wear a mask, the second is to wash their hands regularly.

“As long as you do two things is safe, the first mask standard wear, the second hand washing, develop a habit of hand washing and wearing a good mask, basically no problem, this habit to develop.” He stressed that this habit is still important for the public to do a good job of personal protection at the moment, especially for the elderly.