流感“中招”后还要打疫苗吗？

Core Viewpoint - The article emphasizes the importance of flu vaccination, especially during the current flu season, and addresses common questions regarding the timing and necessity of vaccination after infection or previous vaccination. Group 1: Vaccination Timing and Effectiveness - Vaccination is still effective and necessary even if administered after the optimal period of September to November, as the flu season is currently on the rise, with peaks expected from late December to early January [1] - Timely vaccination can provide protection throughout the winter season, which typically lasts until March of the following year [1] Group 2: Immunity After Infection - Natural infection provides immunity only against one strain of the virus, while the current flu vaccines (trivalent or quadrivalent) can protect against 3-4 different strains, making vaccination important even after having been infected [2] - Vaccination can "fill in the gaps" in immunity, offering broader protection against various strains that may circulate [2] Group 3: Annual Vaccination Necessity - Antibody protection from the flu vaccine lasts approximately 6-8 months, and due to the rapid mutation of flu viruses, the strains circulating each year may differ, necessitating annual vaccination [3] - The flu vaccine for the 2024-2025 season will differ from that of the 2023-2024 season, meaning previous vaccination may not provide adequate protection against new strains [3] Group 4: Vaccine Efficacy and Individual Response - It takes about two weeks for the body to develop sufficient protective antibodies after vaccination, and individual immune responses can vary, leading to different levels of protection [4] - Vaccination significantly reduces the risk of severe illness and death, particularly for high-risk groups such as the elderly, children, pregnant women, and individuals with chronic conditions [4]