Is the double positive of COVID-19 related to the emergence of new mutant strains? Let's hear what the experts say

gossip

Recently, there have been many reports about the reinfection of the new coronavirus online, and many netizens have claimed that they have tested positive for the virus twice. Many people are worried about this, and some even say that the emergence of new variants is related to reinfection.

Is this really the case? Are our antibodies still useful? This article analyzes everyone's concerns one by one.

analyze

Let's talk about the issue of reinfection first. The "second positive" mentioned on the Internet is not a professional term, but an alternative name for the second positive infection on the Internet. Reinfection refers to the situation where a new infection occurs after the first infection is cured. Whether it is the second, third, or more times, it can be called reinfection.

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In fact, the phenomenon of reinfection or repeated infection also exists abroad, and it is not rare. Take New Zealand as an example. As of December 12, 2022, there were 2,019,685 confirmed cases, of which 83,875 were repeated infection cases, and the repeated infection rate was about 4.15%.

According to previous reports, there are also cases of reinfection among domestic infected people. According to Dr. Zhang Wenhong's analysis, **there are two main types of infected people at this stage: first infection and reinfection after the immunity acquired by the previous infected people gradually fades. **Dr. Zhang Wenhong believes that the vast majority of infected people are still the former.

▶ Recently, the number of new infections in the country has been on the rise. Is it related to the newly emerging mutant strains?

According to data released by the Chinese Center for Disease Control and Prevention, as of April 20, the number of positive nucleic acid tests for the new coronavirus reported by various provinces was 2,661, with a positive rate of 1.7%. This data increased in both the number of positives and the detection rate compared with the previous week (April 13). At the same time, the data also showed that the number of XBB.1.16 variants, which were under key monitoring, in local COVID-19 cases also increased from 15 to 42.

This suggests that , on the one hand, XBB.1.16 already exists in China and is on the rise. On the other hand, although the number of cases of XBB.1.16 infection has increased slightly, its proportion is still very low and has not formed a dominant transmission situation.

▶ So, why has the number of infections increased recently?

The new coronavirus has always existed, and low-frequency infections have always existed, but after experiencing a peak, it is now at a relatively low epidemic level.

**On the one hand,** as time goes by, the antibody level in the infected person will gradually decrease, and the effect of the constructed immune barrier will inevitably weaken. When the individual is exposed to the new coronavirus again, and the antibody level is not enough to fully play a protective role, a new infection may occur.

**On the other hand,** when the number of infected people around gradually increases, the mobility of the population increases, and self-protection measures such as masks are not in place, people who have not been infected before may become infected.

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▶ How should we protect ourselves in the face of the following situation?

**Vaccination and strengthening personal protection can still effectively reduce the chance of infection. **From the current situation, antibodies obtained through infection and vaccination still have a good protective effect. Therefore, for those who have not been infected or have recovered from infection, and who meet the requirements in terms of physical condition and time, the best way is to get the new crown vaccine and get a booster shot as needed to increase the antibody level.

At the same time, according to the "Guidelines for the Public to Wear Masks to Prevent New Coronavirus Infection (April 2023 Edition)" issued by the epidemic prevention and control group of the Joint Prevention and Control Mechanism of the State Council, it is reasonable to choose to wear masks to reduce the risk of infection due to contact, especially when traveling, seeking medical treatment and in crowded places.

Many people are concerned about reinfection, which is actually a worry about whether the new variant will cause more severe symptoms. At present, according to relevant reports, no similar situation has been found. Existing data show that the immune escape ability of XBB.1.16 is comparable to that of XBB.1.5, and there are no reports of increased severe hospitalization or death after infection, nor have there been reports of higher disease severity compared with other Omicron subclades. However, in vulnerable groups such as children, the elderly and people with underlying diseases, it is not ruled out that individual differences may cause more severe clinical manifestations.

Some experts believe that the general public does not need to be too afraid of XBB.1.16. Even if infected, the symptoms are relatively mild. However, people with low immunity should pay more attention.

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in conclusion

The harm caused by the new coronavirus epidemic is far from over, so it is not advisable to be careless and let things go, but it is also completely unnecessary to worry too much. In life, what we need to do is to pay more attention to relevant popular science content, strengthen self-protection, protect those who are more susceptible to infection, and try not to be infected. If you have fever, runny nose, cough, muscle aches, fatigue and other suspected symptoms of new coronavirus infection, you must actively seek medical treatment.

Author: Zhang Yu, researcher at the Chinese Center for Disease Control and Prevention, doctor of medicine, and master's supervisor

Review | Li Machao, Associate Researcher, Institute of Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention

The article is produced by "Science Refutes Facts" (ID: Science_Facts). Please indicate the source when reprinting.

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