Beijing, March 3 (ZXS) -- According to the information released by the Chinese Center for Disease Control and Prevention on its official social platform on the 20th, Wang Dayan, director of the National Influenza Center of the Institute of Virus Disease Prevention and Control of the Chinese Center for Disease Control and Prevention, said that China entered the influenza epidemic season about two months later this year than in previous years, and the peak of influenza activity in several provinces has been monitored to have reached an inflection point and began to decline.
Wang Dayan said that the level of influenza activity in China began to increase in early February 2023, and the upward trend was obvious after the end of February, and it had reached a peak period by mid-March. Although the overall level is still high, several provinces have also been monitored that the peak of influenza activity has reached an inflection point and has begun to decline. This year, the influenza season entered about 2 months later than previous years, and the influenza viruses circulating this time were mainly influenza A(H2N3) subtype virus, followed by influenza A(H2N1) subtype virus.
Influenza is generally circulating in winter, why is the flu epidemic in China later this year than in previous years? Wang Dayan said that from the perspective of virus epidemic, the previous autumn and winter influenza epidemic season in China generally began around the end of November, reached a peak in January of the following year, and lasted until about March. From December 11 to January 1, coinciding with the epidemic of the new coronavirus, the measures to prevent and control the new crown are also very effective in the prevention and control of seasonal influenza, so that the epidemic of other respiratory viruses such as influenza has been suppressed to a certain extent.
At the same time, because most people will consciously stay at home, stagger work or stop work after being infected with the new coronavirus, most primary and secondary schools and childcare institutions are on holiday, reducing crowd gathering and the risk of virus transmission, resulting in a low level of influenza activity at the end of 2022 and no seasonal influenza epidemic.
Wang Dayan said that from the perspective of autoimmunity, influenza A(H3N1) subtype virus has not been circulating in China in the past three years, and influenza A(H1N3) subtype and influenza B have not caused a high level of epidemic nationwide. The public's awareness of influenza prevention and control has generally decreased, and the influenza vaccination rate is low, resulting in a decrease in the pre-existing immunity of the population, especially children, to influenza A(H2N1) virus.
Wang Dayan pointed out that after China implemented the "Class B tube" for new coronavirus infection in early 2023, the flow of international and domestic personnel and social activities became normalized, and influenza activities dominated by the H1N1 subtype caused the peak of influenza in China's spring. At the end of February 2023, influenza activity rose rapidly, lagging by about 2 months compared to the previous normal influenza season.
The expert also mentioned that seasonal influenza is not only prevalent in autumn, winter, winter and spring, and that southern Chinese provinces often have a summer flu peak in summer, generally reaching a peak between June and July. (End)