Worldwide, hepatitis B virus (HBV) infection is a major cause of acute hepatitis, and chronic infection with HBV often leads to chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. So far, the most effective way to prevent HBV infection in susceptible population is to inject hepatitis B vaccine. However, long-term protection against hepatitis B virus (HBV) after vaccination remains widely debated. This study aims to carry out a comprehensive study to evaluate the efficacy of hepatitis B vaccine booster from the aspect of humoral and cellular immunity in neonatally vaccinated children in Chongqing.