今年流感高发时间提前！疫苗种类众多，如何选择？

Core Viewpoint - The article highlights the rising trend of influenza cases in southern China, particularly in Guangdong Province, with a recommendation for increased vaccination and preventive measures as the flu season approaches [3][4]. Group 1: Current Situation of Influenza - Guangdong Province is currently experiencing an influenza outbreak, primarily caused by the H3N2 strain, with a noted risk of outbreaks in densely populated areas [3]. - Monitoring data from the China CDC indicates that while northern provinces show low levels of flu activity, southern provinces are seeing an increase [3]. - Clinical observations report a significant rise in flu patients, with symptoms including fever, sore throat, headache, body aches, and fatigue [3]. Group 2: Vaccination Recommendations - The chief expert from Guangdong's CDC recommends flu vaccination as the most effective preventive measure against influenza and its complications, urging all individuals aged six months and older to get vaccinated unless contraindicated [4]. - High-risk groups, including children under five, the elderly, and individuals with chronic diseases, should be prioritized for vaccination [4]. - Vaccination should ideally be completed before the flu season begins, as protective antibodies typically develop 2 to 4 weeks post-vaccination [4]. Group 3: Types of Influenza Vaccines - Influenza vaccines are categorized into trivalent and quadrivalent types, with quadrivalent vaccines providing coverage for an additional strain of B influenza [5]. - Vaccines are further divided into inactivated and live attenuated types, with inactivated vaccines containing "killed" viruses and live attenuated vaccines containing weakened viruses [5]. - The majority of inactivated vaccines on the market are split vaccines, which are produced by breaking down the virus, while subunit vaccines involve further purification of the antigens [5]. Group 4: Safety and Administration of Vaccines - Both split and subunit vaccines are considered safe and effective, with the main differences lying in production methods, costs, and age suitability [5]. - For live attenuated vaccines administered via nasal spray, specific populations are advised against vaccination, including those with compromised immune systems and certain medical histories [6][7].