China News Service, Beijing, July 21 (Yuan Xiuyue and Liu Huan) At present, the sub-branch of Omicron BA.5 has become the main popular strain in the world.
What are the recent changes in the epidemic situation in my country?
Are the current vaccines and prevention and control measures still effective?
What is the long-term variation trend of mutants?
On the 21st, the Joint Prevention and Control Mechanism of the State Council held a press conference to respond to recent public concerns.
The press conference scene.
Photo by Yuan Xiuyue
In the past week, the epidemic has affected 78 cities in 21 provinces
7 provinces report more than 100 cases of infection
Mi Feng, spokesperson of the National Health and Medical Commission and deputy director of the Publicity Department, said that at present, the global epidemic is still at a high level, and the number of new confirmed cases per day has exceeded 1 million many times. Popular strains, China's foreign defense input pressure is increasing.
Recently, local clustered epidemics have been reported in many places across the country, and there are multiple chains of transmission. The epidemic prevention and control situation is severe and complicated.
The comprehensive team of the Joint Prevention and Control Mechanism of the State Council has dispatched working groups to relevant provinces to guide local governments to control the epidemic in the shortest time and at the lowest cost.
He Qinghua, a first-level inspector of the National Health Commission's Bureau of Disease Control and Prevention, introduced that since July, the national epidemic situation has generally fluctuated at a low level. Recently, the epidemic situation in a few areas has rebounded, showing a trend of multiple distribution and frequent occurrence in multiple places. There has been an increase in the number of reported indigenous infections.
In the past week, the epidemic has spread to 78 cities in 21 provinces, of which 7 provinces have reported more than 100 cases of infection.
The epidemics in Lanzhou of Gansu, Beihai of Guangxi, and Zhumadian of Henan are still in the advanced stage, and the risk of social transmission is relatively high.
In general, local epidemics can be effectively controlled in a relatively short period of time after local epidemics occur, and the impact of the epidemic is relatively limited. The ability and efficiency of local epidemic response and disposal have been further improved.
Omicron shouldn't be the last mutant
According to Dong Xiaoping, chief expert of virology at the Chinese Center for Disease Control and Prevention, the transmission power of BA.4 and BA.5 subclades is slightly higher than that of other Omicron variant strains. Higher regeneration index (R0); second, BA.4 and BA.5 subclades in some countries and regions have become prevalent strains; third, in the past 5 weeks, the number of infections has increased in Europe and North America.
The pathogenicity of the BA.4 and BA.5 subclades is generally similar to other Omicron variants, but rapid spread in the elderly population has resulted in severe cases, recent hospitalization rates and ICU use in 12 European countries rates have increased.
Epidemiological mathematical model research shows that the infection rate and mortality caused by BA.4 and BA.5 subclades will increase.
Dong Xiaoping said that virus mutation, especially the mutation of RNA virus, is the basic characteristic of virus survival. , to partially break through the existing immune barrier, so as to reproduce, which is one of the reasons why many viral infectious diseases often show a periodic increase in incidence.
The new coronavirus is indeed a "smart" and "cunning" virus. In just two and a half years, multiple mutant strains have appeared, forming multiple epidemic peaks.
Regarding the mutation of the new coronavirus, most scholars believe that it will exist for a long time, and the Omicron mutant should not be the last mutant. Therefore, the monitoring of new mutants is important for transmission, pathogenicity and immune escape. Impact will be a long-term focus.
Existing prevention and control measures can still effectively deal with BA.4 and BA.5 subclades
Current vaccinations are still valid
So, are our current prevention and control measures and vaccines still effective?
Dong Xiaoping said that although the transmission power of the BA.4 and BA.5 subclades has increased, they still belong to the Omicron variant, and there is no evidence that the existing NPI (non-drug intervention) measures will be ineffective.
In other words, my country's existing prevention and control measures can still be effectively dealt with.
In terms of vaccines, he said that a large number of international and domestic real-world studies have confirmed that the currently approved vaccines, no matter what type, are effective against hospitalization, pneumonia caused by Omicron variant strains (BA.1, BA.2). , Severe/critically ill, and death have a good protective effect, and enhanced vaccination can effectively improve the efficiency of vaccine protection.
Although some in vitro studies at home and abroad have found that BA.4 and BA.5 have obvious immune escape phenomenon, and the neutralization ability of the virus in vitro is reduced, there is no specific data on whether the protective efficacy of the vaccine in the real world is significantly reduced.
Previous Delta variants and Omicron variants (BA.1, BA.2) also showed reduced neutralizing capacity in in vitro studies, but still showed good hospitalization, severe/critical illness, and death in real-world use Therefore, domestic and foreign experts believe that the current vaccination is still effective, and vaccination for the elderly and people with underlying diseases, especially the booster vaccination, is still the most effective preventive measure.
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