流感进入快速上升期！别等“中招”，这样预防还来得及→

Core Insights - The flu positivity rate in China has reached nearly 45%, indicating a significant rise in flu cases, with some provinces experiencing high epidemic levels [1] - The peak of flu activity typically occurs from late December to early January, followed by a decline [2] Group 1: Flu Characteristics - Influenza is an acute respiratory infectious disease caused by the influenza virus, primarily the H3N2 subtype in China this season [3] - The flu virus can spread through droplets from sneezing, coughing, or talking, as well as through contact with contaminated surfaces [4] Group 2: Symptoms and Risks - Flu symptoms are severe and include sudden high fever (often reaching 39°C to 40°C), chills, severe headaches, muscle aches, and extreme fatigue, posing a higher risk of serious complications for vulnerable populations [7][10] - In contrast, common colds primarily affect the nose and throat, with milder symptoms and a lower risk of severe complications [5][6] Group 3: Prevention and Vaccination - Vaccination is crucial for flu prevention, with experts stating that it is never too late to get vaccinated, as antibodies develop within 2 to 4 weeks [17] - The flu vaccine significantly reduces the risk of severe illness and death, with estimates showing a reduction of over 40% in risk for the general population [18] - The World Health Organization recommends annual vaccination due to the changing nature of circulating flu strains [19]