How many doses of the flu vaccine are needed?
Feb 08, 2025
Source: Cainiu Health
Dr. Ren Yi
Introduction
Under normal circumstances, children require two doses of the influenza vaccine, while adults require only one dose. If necessary, administration should be performed under a doctor's guidance. Children, especially young children, have immature immune systems and relatively weaker immune responses to vaccines. After receiving the first dose of the influenza vaccine, the body begins to produce antibodies, but the antibody levels may be relatively low.
Generally, children require two doses of the influenza vaccine, while adults require only one dose. If necessary, administration should be conducted under the guidance of a doctor. The analysis is as follows:
Children, especially young children, have immature immune systems and relatively weaker immune responses to vaccines. After the first dose of the influenza vaccine, the body begins to produce antibodies, but the antibody levels may be low and the duration short, making it difficult to provide sufficient and long-lasting protection. The second dose serves as a booster, stimulating the immune system again to produce more and more effective specific antibodies, which remain in the body for a longer period.
The immune systems of adults are relatively mature and stable, and their responses to vaccines are more rapid and robust. After the first dose of the influenza vaccine, the immune system can efficiently recognize the antigenic components, quickly initiate the immune response, generate large amounts of specific antibodies, and establish immune memory. Therefore, an additional booster dose is generally not required to enhance the immune effect.
After vaccination, it is important to keep the injection site clean and dry and to avoid scratching in order to prevent local infection.
