Recently, the XBB strain has attracted attention, and terms such as "montmorillonite powder", " norfloxacin " have also been hotly searched on major platforms.
Xu Wenbo, director of the Institute of Viral Diseases at the Chinese Center for Disease Control and Prevention, said that BQ.1 and XBB are new mutant branches of Omicron and have become dominant strains in some European and American countries, mainly characterized by increased transmissibility and immune evasion capabilities.
XBB strain that has attracted a new round of attention. What is the pathogenicity of ? ? " Life Times " (search "LT0385" in WeChat to follow) combines the interpretations of many experts and gives protection tips.
Our country has detected the introduction of XBB strains
In the past three months, our country has detected the introduction of BF.7, BQ.1, and XBB. However, BQ.1 and XBB have not yet formed dominant transmission in our country. The dominant transmission is still BA.5.2 and BF.7.
Chen Saijuan’s team from Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine and Fan Xiaohong’s team from Shanghai Public Health Clinical Center jointly conducted research and evaluation, and conducted genome sequencing on 378 randomly selected samples from patients admitted to the Shanghai Public Health Center during the autumn and winter of 2022.
Analysis of the novel coronavirus genome sequencing in Shanghai in the fall and winter of 2022
found that these viral genomes contain data from the Global Initiative for Sharing All Influenza Data Of the 30 Omicron subtype strains recorded in Curry, 355 (95.95%) genome sequences are concentrated in 5 Omicron subtypes. The main strains include BF.7 and BA.5.2 that have been reported to be popular in Beijing and Guangzhou, and BQ.1 and XBB that have recently appeared in Europe and the United States.
Among the 25 cases of XBB families, there are 3 cases of XBB.1.5, all of which are imported cases from abroad.
Yuan Zheng'an, a member of the expert group of the Shanghai Epidemic Prevention and Control Leading Group, said that the Omicron XBB strain discovered in Shanghai has not yet caused local spread in society.
has become the most popular strain in the United States.
Data released by the U.S. Centers for Disease Control and Prevention on December 30, 2022, Eastern Time, show that it estimated that 40.5% of new coronavirus infection cases in the United States that week were caused by the highly contagious Omicron subtype strain XBB.1.5.
Scientists said that due to its extremely high "immune evasion" ability, XBB.1.5 has quickly replaced BQ.1.1 and BQ.1 and become the most popular strain in the United States. CDC response in
: Is XBB more pathogenic?
Xu Wenbo said that the pathogenicity of the XBB strain is not significantly different from that of other series of Omicron variants, and the severe disease rate and mortality rate have not significantly increased in the countries where they are endemic., "There have been no reports of increased severe illness and death caused by BQ.1 and The sub-branch of Kron is a recombinant mutant strain of the variant strain below BA.2, which has enhanced immune evasion ability. It is popular in some foreign areas, leading to an increase in the number of infections. However, foreign data shows that its pathogenicity is no different from previous strains. "
Studies have shown that the key mutation F486P of XBB.1.5 gives it a higher binding affinity to the human ACE2 receptor. ACE2 is the receptor for the new coronavirus to invade the human body, which means that XBB.1.5 is more likely to infect the human body.
ACE2 plays an "important role" in the process of new coronavirus infection
Xu Wenbo said that XBB has not yet formed a dominant transmission in my country (currently BA.5.2 and BF.7 are still the main ones), but its transmission advantage will gradually increase, and it may form a common cycle with BA.5.2, BF.7 and other more than 50 imported sub-branches.
Will be reinfected with XBB after Yang Kang?
Li Tong once said that the immune evasion ability of the current XBB strain has been enhanced, which is different from the BA.5 popular in my country. After a period of time after infection with BA.5, the level of protection decreases. When encountering a strain with strong immune evasion ability, the risk of reinfection will increase.
However, reinfection mainly occurs in some people with low immunity.People with normal immune functionThe risk of reinfection in a short period of time is relatively small, and the symptoms after infection are usually milder than the first time.
Does the XBB strain prefer to attack the digestive tract?
Regarding the symptoms of vomiting and diarrhea caused by the XBB strain reported online, Li Tong once said that some people infected with the new coronavirus do have symptoms of vomiting and diarrhea, which usually resolve on their own in 1 to 3 days. It has not been found that the XBB strain is more likely to invade the cardiovascular and cerebrovascular systems and digestive system . Medications for treating respiratory tract infections and digestive tract infections can be properly prepared, and there is no need to hoard them in large quantities.
Wang Xinyu, deputy director of the Department of Infectious Diseases at Huashan Hospital Affiliated to Fudan University, said that diarrhea in patients infected with the new coronavirus is not too rare among symptoms other than the respiratory tract. Judging from foreign reports, XBB can also cause diarrhea, but there are no more common or serious signs. XBB still mainly invades the respiratory tract, so "XBB mainly attacks the intestines" is not true.
The key is to protect well
In the face of new strains, scientific protection is still the key.
Insist on wearing a mask
Masks are still one of the most effective means of blocking the spread of Omicron. When taking public transportation or passing through crowded places, masks should be worn at all times.
Vaccination is still an important means
Vaccine is an effective means to protect vulnerable groups. Those who have not yet been vaccinated should seize the time to get vaccinated as soon as possible as long as they meet the conditions. Elderly people with chronic diseases must ensure that their condition is stable while avoiding treatment interruptions caused by drug shortages.
Those who have been infected with the new coronavirus (patients or asymptomatic infections) can be vaccinated with one dose after 6 months after being fully informed.
Don’t blindly hoard/take medicine
Taking diarrhea symptoms as an example, Wang Xinyu said that diarrhea caused by COVID-19 is usually mild and can generally resolve itself in a short period of time without medication.
If diarrhea is severe, the lost fluids and electrolytes should be replenished, and oral rehydration is usually sufficient instead of taking some antidiarrheal drugs and antibacterial drugs.
In addition, protective measures such as washing hands frequently, opening windows for ventilation, and paying attention to social distance still need to be adhered to. ▲
Editor of this issue: Xu Menglian
Copyright statement: This article is original to "Life Times" and any unauthorized reproduction is strictly prohibited.
