流感来势汹汹，今年毒株不同？四价疫苗比三价疫苗预防效力更强吗

Core Insights - The recent flu activity in southern China is on the rise, with a notable increase in diagnosed flu cases reported by healthcare professionals [1] - The predominant flu strain this year is H3N2, which differs from last year's H1N1 strain, leading to concerns about vaccine effectiveness [2][3] - Vaccination is emphasized as the most effective preventive measure against flu, with a preference for quadrivalent vaccines over trivalent ones due to better efficacy against circulating strains [4] Group 1: Flu Activity and Symptoms - Flu activity has increased in southern provinces of China, with healthcare professionals observing more patients diagnosed with flu [1] - The main strain circulating this year is H3N2, which has a higher mutation rate compared to H1N1, complicating vaccine matching [3] - Flu symptoms are more severe than those of a common cold, including high fever, severe headaches, and muscle aches, with significant fatigue [2] Group 2: Vaccine Information - There are three types of flu vaccines approved in China: trivalent inactivated, quadrivalent inactivated, and trivalent live attenuated vaccines [4] - Quadrivalent vaccines provide better protection against this year's circulating strains, but trivalent vaccines are still beneficial if quadrivalent options are unavailable [4] - Vaccination should ideally be completed by the end of October to ensure adequate antibody protection before flu season [5]