专家：每年接种流感疫苗是维持有效防护的一个必要措施

Core Viewpoint - The Chinese health authorities emphasize the importance of annual flu vaccination based on global monitoring data and the need for updated vaccine strains to match circulating viruses [1][2]. Group 1: Vaccine Selection and Monitoring - The flu vaccine strains used in China are selected and recommended by the World Health Organization (WHO) based on global flu surveillance data, including epidemiological data, antigen analysis, and genetic evolution analysis [1]. - China's flu monitoring system supports WHO's vaccine strain recommendations, consisting of 665 national-level laboratories and 1,041 sentinel hospitals that track flu dynamics and detect new variant viruses in real-time [1]. Group 2: Vaccine Efficacy and Recommendations - Vaccination is recognized as the most economical and effective method to prevent flu and its severe complications, with common adverse reactions being mild [1]. - Recent international studies show that flu vaccination can prevent 67% of hospitalizations in children, 43% of severe cases in children, and 48% of adult hospitalizations [2]. - Annual flu vaccination is necessary for all individuals over 6 months old without contraindications, due to the frequent mutation of flu viruses and the waning efficacy of the vaccine over 6 to 8 months [2]. - High-risk groups, including children, the elderly, teachers, healthcare workers, and individuals with underlying health conditions, are particularly encouraged to receive the flu vaccine [2].