Do I need to get the flu vaccine every year once I start getting it?
Feb 13, 2025
Source: Cainiu Health
Dr. Ren Yi
Introduction
Under normal circumstances, influenza refers to the flu. The influenza vaccine does not necessarily need to be administered every year once given, but annual vaccination is generally recommended. For high-risk groups such as the elderly, children, pregnant women, individuals with chronic diseases, and healthcare workers, who are more susceptible to influenza virus infection and severe complications, it is recommended to actively receive the influenza vaccine annually.
Generally speaking, influenza refers to the flu. The influenza vaccine does not necessarily need to be administered every year once given, but annual vaccination is usually recommended. Detailed explanation is as follows:
Influenza viruses are highly variable and undergo antigenic changes, with new viral strains emerging each year. Therefore, annual influenza vaccines are formulated based on virus strains recommended by the World Health Organization to provide protection against the influenza viruses expected to circulate in that year. This also means that even if vaccinated in the previous year, due to changes in the viral strains, re-vaccination is still necessary.
The protective effect of the influenza vaccine typically lasts for about one year. Over time, antibody levels in the body gradually decline, and the vaccine's protective efficacy also diminishes. Therefore, to maintain effective immunity, it is recommended to receive a new influenza vaccine annually.
For high-risk groups such as the elderly, children, pregnant women, individuals with chronic diseases, and healthcare workers, who are more susceptible to influenza infection and severe complications, active annual vaccination is strongly recommended.
