A stronger mutation plant appears!Xi'an emergency control

06.07.2022

Number of this text: 1322, the reading time is about 2 minutes old

Introduction: The traceability of this round of epidemic virus genes in Xi'an shows that the popular mutated strains are Omikon BA.5.2 branches. Xi'an will take 7 days of temporary management and control measures from July 6.

Author | First Financial Money Children's Heart

On July 5th, the Xi'an Centers for Disease Control and Prevention reported that the traceability of the virus gene of the epidemic virus in Xi'an showed that the popular mutated strains were Omikon BA.5.2 branches. This is also the first time that my country has notified Omikon BA.5 subtypes in the local area. Xi'an will take 7 days of temporary management and control measures from July 6.

Ma Chaofeng, deputy director of the Xi'an Centers for Disease Control and Prevention, introduced at the epidemic prevention and control conference that BA.5.2 branches have a low degree of matching and other regions in China. This mutant plant has a shorter intergenerational and transmission time, faster transmission speed, higher proportion of asyptically infected, more hidden infection, greater virus load, and stronger infectivity. The strain has caused a new round of popular peaks worldwide. Since May of this year, the number of cases in Africa, the Americas and Europe has surged.

A virusist explained to the First Financial reporter that the BA.5.2 branch is Omikon BA.5 subtype branch. In May of this year, the English Weekly released by the China Disease Control and Prevention Center introduced that the first infection of the first new crown virus Omiroko in Mainland China found the BA.5 infection. However, this round of epidemic in Xi'an is the local dissemination of the BA.5 subtype branch that China has confirmed.

At present, the BA.5 subtype variable strains have been discovered in at least 63 countries/regions and began to occupy the dominant position. "Obviously, BA.4 and BA.5 already have a stronger competitive advantage, and push the great popularity in many places in Europe and the United States to a new round of orgasm." The above experts told the first financial reporter.

Because the new mutation strains have obtained new mutations, improved the adaptability of the virus, and also enhanced the infectiousness. Some researchers estimate that the infectiousness of BA.5 can be 36%higher than that of the BA.2 mutant strain, and neutralized experiments show that the immunity induced by BA.1 and BA.2 The effect is poor. Cell culture experiments show that the replication efficiency of BA.4 and BA.5 in human alveoli epithelial cells is higher than BA.2. Compared with BA.2, BA.5 is better fused with host cells.

Professor Lu Hongzhou, Dean of Shenzhen Third People's Hospital, previously told the First Financial reporter: "BA.4 and BA.5 spread faster than previous mutant strains and have strong immunization and escape. The number of cases caused by rising cases is faster and the possibility of becoming the mainstream strain. If the intervention measures for inbound control and community communication are not performed, the strain is more likely to spread further. "

However, he also stated that the current research shows that although vaccination to strengthen the vaccine cannot effectively block the infection of sub -variants, it can effectively prevent the severe illness and death caused by it. "Generally speaking, the immune protection aroused by the vaccine can be maintained for more than 6 months." Lu Hongzhou said.

At present, whether the BA.5 subtype variable strains can cause more serious diseases than the previous Omikon mutant strains, such as BA.1 and BA.2, still need more real -world data analysis. The US FDA has requested vaccine manufacturers to redesign the vaccine for the new BA.5 subtype.

In addition to BA.5, the emergence of BA.2.75, another subtype of BA.2, has recently attracted great attention. The mutant plant has begun to be popular in some places. The popular speed in India and other places can already be with BA. 5 Combination, and even some people call the mutant strain "the second generation of Omikon."

Some Indian researchers said that BA.2.75 is currently spreading at 16%per day in India. The mutant strain has obtained 16 new mutations, 8 of which are located in the virus's thorns area and 4 are located in the receptor -binding domain. Essence

However, experts said that the current data on the spread of BA.2.75 is still limited, and there is no data in the laboratory that harmonize and immune to escape, so it is difficult to determine whether the mutant strain can win in the competition with BA.5.

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