Abstract
What is already known about this topic? Vaccinations are the most effective way to prevent influenza virus infections and severe outcomes. Influenza vaccine effectiveness can vary by seasons. What is added by this report? This report monitors the antibody level among the population over time after administration of the quadrivalent or trivalent split influenza vaccine. What are the implications for public health practice? Real-time monitoring of serum antibody changes after vaccination provides important data for the development of reasonable and effective strategies for influenza prevention and control.