Does it take 15 days for the test result to turn negative to produce antibodies? Experts respond!

It is said online that it takes 15 days for antibodies to be produced after "Yang Kang". Is this true? Can booster shots be given after "Yang Kang"? Li Dongzeng, chief physician of the Department of Infectious Diseases at Beijing You'an Hospital, explains the concerns of netizens!

How to determine whether you have turned negative?

According to the ninth edition of the diagnosis and treatment plan, the first thing is that the symptoms should improve , such as the body temperature being normal for more than three days, and the respiratory symptoms disappearing or significantly relieved. If there is pneumonia, then the lesions in the lungs on the CT scan are also beginning to absorb and improve.

In addition, two nucleic acid tests are negative , and the interval between the two tests must be more than 24 hours, or the CT value of the nucleic acid is greater than or equal to 35, so that it meets the conditions for turning negative. Does it mean that it is no longer contagious after turning negative?

We currently believe that if the above conditions are met, the infectiousness is already very low.

If you still have coughing symptoms, it is recommended that you wear a mask when you return to work or go out to visit relatives and friends, especially those working in important positions such as nursing homes and medical institutions. You must take good protection. If we want to visit the elderly, infants and young children, it is best to wait until at least 10 days have passed since the onset of the disease, and at the same time meet the conditions for turning negative, so it can be basically considered that there is no problem. It is said on the Internet that "antibodies can only be produced about two weeks after positive, so it is most likely to be infected again about a week after positive", is this true?

This is inaccurate.

The specific antibodies we often talk about do take two weeks to reach a relatively high level, or a level that we can detect. But in fact, our immune system has already started working the moment the virus enters our body. The protective antibodies produced subsequently will reach a peak in two to three weeks and last longer, but it does not mean that we have no protection within these two weeks .

If the virus does enter the body at this time, it can be quickly cleared, and it is relatively less likely to be infected. So it is not true that it is easy to be infected within two weeks. This statement is inaccurate. In general, the longer we are infected, the lower the antibody level in our body, and the greater the risk of infection. If a family member has turned negative and recovered, will they still be infected if they take care of other positive family members at this time?

After being infected, you will be immune to the virus and will not be infected again, so you can rest assured and take care of other family members.

Why do some people still feel chest tightness, shortness of breath and weakness after Yang Kang?

Many people will experience high fever, body aches, fatigue, excessive sweating, headache and sore throat when infected. Therefore, after getting sick this time, some people will continue to have symptoms of physical fatigue, weakness, and even chest tightness, which usually subside within two weeks.

If you feel that you are still not in good condition, you can rest for a few more days. Or, when we return to work, if you find yourself feeling weak again, you can rest again. It doesn’t matter. For young people with normal immune function, most of them can basically recover to their pre-illness state within two weeks. But don’t do very heavy work immediately after you recover, or do strenuous exercise or fitness immediately. We still have to proceed step by step. Once you find problems such as fatigue and sweating, take a rest quickly. Some people say that "after being infected with the new coronavirus once, it is equivalent to being vaccinated with the new coronavirus vaccine once." Can Yang Kang rest assured in the future?

Infection certainly cannot replace vaccines, but it can indeed act as a vaccine, preventing us from getting infected again for a short period of time. But this does not mean that we can go wild after being infected once.

First of all, the virus is still mutating. After we are infected, we have cross-protection against similar variants of the virus, but if the virus continues to mutate, or if it is a more distantly related strain, our risk of infection will increase. There are other respiratory infectious diseases in winter and spring, such as influenza, adenovirus, and respiratory syncytial virus, so we must continue to maintain good hygiene habits, wear masks, wash hands frequently, open windows for ventilation, maintain social distance, and pay attention to coughing etiquette.

How long after testing positive can I get the booster shot?

After recovery, the protection generally lasts for 3 to 6 months. Young people can get a booster shot after 6 months. The elderly can get a booster shot after 3 months because their protection is shorter. Is it possible for a person to be infected multiple times due to different strains?

Yes, there are. Someone may have been infected with the original strain once, the Delta strain once, and the Omicron strain once. According to foreign reports, there are indeed many people who have been infected twice; there are fewer people who have been infected three times, but there are some. Infection four or five times is very rare, and it is only reported in some individual cases. Because we can get a certain degree of protection every time we are infected, the risk of reinfection will be smaller, and the symptoms after reinfection will be alleviated. So overall, everyone does not need to worry too much about reinfection in the future.

The antigen turned negative and then positive again.

Is it not completely healed?

Is it contagious after “re-positivity” and “reinfection”?

Who is more likely to suffer from "secondary infection"?

A quick picture

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Source: CCTV News Client, Beijing Daily