At present, a large number of people infected with the new coronavirus
are gradually getting better
Many people have also returned to work one after another
Many people are worried
If the strain of the new coronavirus is different
Will they be infected by the new coronavirus again?
In this regard, Zhang Boli, an academician of the Chinese Academy of Engineering,
answered questions related to the secondary infection of the new coronavirus
Zhang Boli, an academician of the Chinese Academy of Engineering. Xinhua News Agency reported
"Yangkang" has a low probability of secondary infection within 3 to 6 months.
"The probability of re-infection with the new coronavirus is mainly related to human immunity level, virus strain mutation and later personal protection." Zhang Boli said that compared with early mutant strains, the strains of the Omicron family can cause more breakthrough infections and repeated infections, and can escape the antibodies in people who have recovered from the new coronavirus infection.
However, Zhang Boli said that everyone does not need to worry too much. Although there is no evidence from a large sample of people to show the specific time for sustained immunity after infection with the Omicron variant, the human immune system is already functioning after infection with the new coronavirus. Current clinical observations show that the probability of secondary infection with the new coronavirus within 3 to 6 months after infection is still relatively low.
"Although it is unlikely to be infected with the same new coronavirus mutant strain again in a short period of time, people with poor immunity are prone to repeated infection , including the elderly, infants, people with underlying diseases, and immune People with epidemic deficiencies are at risk of secondary infection in the short term, especially when faced with new mutant strains. "Zhang Boli said that in addition, people in high-risk positions such as doctors and nurses are in working environments with high risk of transmission, are exposed to many mutant strains, work intensively, and are at high risk of secondary infection.
Many people are worried that a second infection with the new coronavirus will worsen symptoms. Zhang Boli said that the situation of a second infection with the new coronavirus varies from person to person. And after secondary infection, the severity of the disease is related to various factors such as the dose of virus infection, the pathogenicity of the new coronavirus variant, and personal health status. However, judging from most current reports, because the body has developed immunity, the symptoms of the second infection will generally be milder than the last time.
However, Zhang Boli emphasized that there are also a few research reports showing that compared with patients who have been infected only once, patients who are infected three times have a higher risk of complications, including pulmonary, cardiovascular, diabetes, , gastrointestinal and nervous system complications.
It is recommended that "Yangkang" should be vaccinated with the new coronavirus vaccine after 6 months.
"It is mainly a re-infection of the new coronavirus mutant strain, so personal protection should continue even after the infection turns negative." Zhang Boli emphasized that "Yangkang" can be vaccinated with the new crown vaccine after 6 months. It is best to adopt a sequential strategy and inject the heterogeneous vaccine to strengthen the immune barrier.
For those who have recovered from COVID-19, the best way to prevent secondary infection during the epidemic is to implement protective measures, including wearing masks, paying attention to hand hygiene, taking breaks, ventilating frequently, and maintaining social distance. Especially the elderly and children with "yang to yin" patients should keep warm, gather as little as possible, ensure good hygiene habits, pay attention to nutritious diet, enhance immunity, and reduce the risk of reinfection.
If reinfection occurs, we must first distinguish between "re-positive" and secondary infection.
"recovery": occurs within 2-3 weeks after turning negative. Patients generally have no obvious clinical symptoms. The main reason is that the fragment of the residual virus in the body is positive. is generally not contagious;
secondary infection: generally occurs within a few months to a year after the first infection. It is equivalent to a new infection. Generally, there are clinical symptoms, and the virus nucleic acid load is high and contagious.
"Patients with 'Fuyang' do not need to be treated anymore, they just need to pay attention to rest, reasonable diet and nutrition." Zhang Boli reminded that patients with secondary infection need to receive standardized treatment again and strictly implement personal protection, do self-isolation , pay attention to the protection of family members and colleagues, and reduce the risk of epidemic spread.
Is Omicron more susceptible to reinfection?
How long do antibodies last after recovery from infection?
How should we protect ourselves personally?
Regarding the topic of "secondary infection"
Wan Mobin, chief physician of the Department of Infectious Diseases at the First Affiliated Hospital of Naval Medical University (Shanghai Changhai Hospital)
Wan Mobin also answered
01
Why does "secondary infection" occur?
Wan Mobin pointed out that the main reasons for secondary infection or repeated infection come from two aspects.
Autologous causes
For example, if it has been too long since the last vaccination (more than half a year or even a year), the antibody content in the body continues to decline; or the last infection was mild or asymptomatic, and the amount of antibodies produced in the body is relatively small; and some people have low immunity or have diseases in the immune system, and are prone to secondary infections.
Causes of the virus
Currently, the new coronavirus mutates very quickly. Take this round of Omicron as an example. It is difficult for the human body to establish a comprehensive immune barrier against different subtypes of Omicron. After being infected with a certain subtype of Omicron, it is still possible to be infected with another strain of Omicron.
In April this year, foreign media reported that a medical staff in Spain was infected with the new coronavirus (different strains) twice in just 20 days. This is considered to be the shortest time interval between two infections since the outbreak of the new coronavirus.
02 How to distinguish between “secondary infection” and “relapse”?
For some people infected with COVID-19, after their nucleic acid turns negative after recovery, the nucleic acid may still be positive again. There are two indicators for judging whether this situation is a secondary infection or a re-infection:
Look at the time
In the early stage of infection, the confirmed person has a higher chance of re-positive. Generally speaking, the chance of re-positive is highest in the first 3 months after infection, with a probability of about 1% to 2%.
Look at the viral load (the lower the viral load, the higher the CT value)
As for the cases of re-positive cases, the viral load of the patients is relatively low, and the CT value of most patients is above 35. In patients with secondary infections, the viral load was relatively high and the CT value was lower than 35.
03 Is Omicron more susceptible to reinfection?
Wan Mobin believes that after being infected with some infectious diseases, the body will use the previously formed immune mechanism to protect itself and will not be easily reinfected. However, there is no lifelong immunity to the new coronavirus, and different strains have different abilities to cause multiple infections.
In March of this year, scholars from Weill Cornell Medical College (Qatar Campus) published a study in the New England Journal of Medicine, evaluating the protection brought by previous infection with the new coronavirus. The
study found that 270 days after infection, the protection against re-infection with different variants was: 90.2% for the Alpha strain, 85.7% for the Beta strain, 692% for the Delta strain, and 56% for the Omicron strain.
Obviously, is more likely to cause reinfection than delta and previous variants. However, despite this, the secondary infection rate of Omicron is still very low. The Hong Kong Center for Health Protection recently stated that in November, about 4% of confirmed cases in the local community in Hong Kong were suspected of being "secondary infections."
04 How long do antibodies last after recovery from infection?
Li Tong, chief physician of the Department of Infectious Diseases at Beijing You'an Hospital and a medical expert at Xiaotangshan Fangcang Hospital, once said that after being infected with the new coronavirus, immunity against the strain generally lasts for more than half a year.
Zhong Nanshan, an academician of the Chinese Academy of Engineering, also said that foreign data show that regardless of whether there are symptoms or not, once a person is infected with Omicron, 78% of the people will not be infected again for a long time.
The Hong Kong Center for Health Protection cited World Health Organization data and pointed out that although there is currently no evidence to show the specific time of immunity derived from infection with the Omicron mutated virus strain, based on the situation of previous mutated virus strains, the immunity time is expected to last at least 90 days.
Wan Mobin believes that for most people, the time since the last diagnosis is less than 3 months, and the chance of secondary infection is relatively low. However, it does not rule out that some elderly, frail, and seriously ill patients are at risk of secondary infection within 3 months, nor does it rule out the possibility of being infected with new mutant strains in a short period of time.
05 Will infected people become less contagious?
The infectivity of people infected with COVID-19 is related to multiple factors. The infectivity will not become stronger or weaker because of secondary infection or repeated infection.
Multiple factors include virus quantity, virus concentration, virus activity, etc. Generally, the viral load, viral concentration and viral activity of the new coronavirus are positively related to its infectivity.
06 How to protect yourself after recovering from infection?
After cured COVID-19 patients are discharged from hospital and asymptomatic infected persons are released from isolation, they still need to strengthen their awareness of self-protection. Getting vaccinated, wearing a mask, maintaining a 1-meter social distance, and trying to avoid crowded and poorly ventilated indoor spaces are still effective ways to prevent repeated infections.
In addition, in daily life, we should also increase nutrition, especially increase protein intake, insist on exercising, ensure a good mentality, and improve the body's immunity.
Source | Southern + Client, Science and Technology Daily, Life Times, Popular Science China, Jinyun, Huashang.com
Editor | Xiaoyu
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