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Will XBB.1.5 cause a new round of infection peak?
experts explain
in detail. Recently, the Omicron subtype XBB.1.5 has attracted widespread attention. Currently, Shanghai has discovered the XBB.1.5 strain during surveillance of imported cases overseas.
html On the 62nd, according to Xinmin Evening News, in response to Shanghai citizens' concerns about the introduction of strains BQ.1 and XBB from Europe and the United States, Yuan Zheng'an, a member of the expert group of the Shanghai Epidemic Prevention and Control Leading Group, said that the Omicron BQ.1 and XBB strains currently discovered in Shanghai have only been detected in a very small number of incoming quarantine personnel and have not yet caused local spread in society.Relevant experts said that there is no need to worry too much about the virulence of XBB.1.5 and the risk of secondary infection of and .
These samples came from COVID-19 patients in Shanghai. They were randomly collected from November 23 to December 22, 2022. Gene sequencing confirmed 30 known Omicron subtype strains, and no new new coronavirus mutant strains have been found. In addition, among the 25 cases of XBB families monitored in Shanghai this time, 3 cases of XBB.1.5 were also imported cases from abroad and did not cause local transmission.
Researchers said that the strains among imported patients are relatively complex, and most of them are detected for the first time in my country. The current sequencing results show that as there are many new virus strains imported from abroad, routine virus strain detection still needs to be carried out to provide a basis for subsequent scientific prevention and control.
According to reports, domestic and foreign experts predict that XBB.1.5 will become the main strain in the world in a short period of time and requires close attention. Another important reason is that the human ACE2 binding affinity of XBB.1.5 is almost equal to that of BA.2.75, which may cause XBB.1.5 to acquire more mutations like BA.2.75 in the future. However, XBB.1.5 currently has little pressure on immunity to and will not evolve quickly. How pathogenic is
XBB.1.5?
According to media reports, data released by the US Centers for Disease Control and Prevention on December 30, 2022 Eastern Time showed that an estimated 40.5% of new coronavirus infection cases in the United States that week were caused by the XBB.1.5 strain. Scientists also said that due to its extremely high "immune evasion" ability, XBB.1.5 has replaced BQ.1.1 and BQ.1 as the most prevalent strain in the United States.
research shows that the immune evasion ability of XBB.1.5 is equivalent to that of XBB.1, but the key mutation F486P gives it a higher binding affinity for the human ACE2 receptor - ACE2 can be regarded as the "gate" for the new coronavirus to enter human cells, which means that XBB.1.5 is more likely to infect the human body.
In this regard, Jin Dongyan, a professor at the School of Biomedical Sciences at the University of Hong Kong and an expert in virology, said that while F486P has slightly increased its ability to bind to the ACE2 receptor, its immune evasion ability has also been slightly weakened. This once again shows that replicating infection and immune escape are linked. The current change is genetic drift , which is the phenomenon that accidental changes cause the next generation gene frequency to be different from the current generation. In fact, it does not deviate too far from the baseline.
Jin Dongyan said that XBB.1.5 has not caused significant changes in the number of infections, hospitalizations, and deaths in the United States, and there is no need to worry too much about its pathogenicity and risk of secondary infection. "Except for the immune evasion ability being enhanced to a certain extent, the changes in other aspects are relatively small," he said.
Can medical institutions cope with the new strain?
On January 1 this year, according to CCTV's "Face to Face" program, many cities began to experience a peak of new coronavirus infections in early December 2022, and the number of infected patients surged. The hospital's fever clinics were the first to come under pressure.
Regarding the question of whether XBB.1.5 will cause a new round of infection peak in mainland China, Professor Zhang Jiming, deputy director of the Department of Infectious Diseases at Huashan Hospital affiliated to Fudan University, responded to China News Service: "There is no need to worry, it is somewhat exaggerated."
Zhang Jiming said that the new strains currently monitored still belong to the Omicron subtype, and are still respiratory viruses, that is, they mainly infect the respiratory tract, and their pathogenicity has not increased. At the same time, combined with the experience of handling the first round of infection peaks, Medical Resources can handle it.
Jin Dongyan also said that the emergence of XBB.1.5 in the United States has not changed the basic trend of the new crown epidemic in the United States. The explosion of BA.2
Comprehensive People’s Daily WeChat, Banyuetan WeChat public account, China News Network
Source: China search
