The difference between 3 shots of Hepatitis B vaccine and one shot is mainly the antibody titer and antibody stabilization effect. Hepatitis B vaccine 3 shots generally refers to the routine immunization program of Hepatitis B vaccine, which needs to be injected 3 times, respectively in month 0, month 1 and month 6. Generally 96% of the vaccinated patients can produce hepatitis B surface antibody after completing 3 injections, with high antibody titer, and the antibody effect can be maintained at a high level, and the protective effect lasts for at least 12 years. The first injection of hepatitis B vaccine refers to the first injection in the routine vaccination procedure of hepatitis B vaccine, generally only 30% of the vaccinated people can produce hepatitis B surface antibody after completing the first injection, with lower antibody titer, and the stabilization effect of the antibody is not good, and the protection effect is also relatively weak. It is necessary to continue to complete the second and third injections in accordance with the vaccination program in order to obtain a long-lasting and sustained protective effect.