毒株与去年不同，流感季或提前，防护要趁早

Core Viewpoint - The flu season in China is expected to arrive earlier this year, with a predominant strain of H3N2, differing from last year's H1N1 strain, leading to lower immunity levels in the population [1][2]. Summary by Sections Flu Characteristics - The main circulating strain this year is H3N2, with an increase in flu cases reported in Japan, the UK, Germany, and Italy since October [2]. - Symptoms of H3N2 include fever, cough, sore throat, body aches, fatigue, and headaches, similar to H1N1 and B strains [3]. Comparison with Common Cold - Flu is caused by influenza viruses (A and B), while common cold is caused by other viruses like rhinovirus [4]. - Flu has a higher transmission rate, significant seasonal peaks, and more severe symptoms, including high fever (39-40°C) and potential complications like pneumonia [4][5]. Vaccination Recommendations - Vaccination is the most effective method to prevent flu and reduce severe cases, with the recommended vaccination period being September to November [6]. - Annual vaccination is necessary due to the rapid mutation of flu viruses, which may differ each year [7]. High-Risk Groups - The National Health Commission recommends vaccination for all individuals over 6 months old, especially for high-risk groups such as children under 5, the elderly over 65, pregnant women, and those with chronic health conditions [8][11]. Pediatric Considerations - Children, especially those under 5, are at higher risk for severe complications from flu, necessitating careful monitoring and care [10][12].