Influenza A (H3N2) is a respiratory infectious disease caused by infection with the influenza A (H3N2) virus, which can be characterized by fever, chills, chills and headache. Influenza is a more serious acute respiratory infectious disease caused by influenza virus infection, which can be categorized into four types, namely type A (type A), type B (type B), type C (type C) and type D (type D). Type A can be subdivided into many subtypes, and H3N2 is one of the subtypes of influenza A virus. Currently, the influenza A viruses that cause annual seasonal epidemics are the H1N1 and H3N2 subtypes, which are mainly transmitted through droplet transmission of respiratory secretions, but also through direct or indirect contact with mucous membranes in the mouth, nasal cavity, eyes, and other mucous membranes. After infection, there may be fever (high fever up to 39~40℃), sore throat, cough, nasal congestion, runny nose, headache, myalgia, malaise and other symptoms, and influenza vaccination is the most effective means to prevent influenza. If you experience any of the above symptoms, it is recommended that you seek prompt medical attention.