The booster vaccine has an immune-boosting effect. Vaccination can help the body to produce antibodies to protect itself against the virus, thus reducing the incidence of pneumonia, as well as reducing the rate of severe illness and mortality caused by the disease. However, antibodies do not persist in the body, and booster shots can increase antibody levels dramatically, thereby enhancing the immune response. The booster vaccination improves an individual’s defense against the new coronavirus and also provides good immunity against mutated strains of the virus. It is recommended that a booster shot be given after two doses of the new coronavirus vaccine have been completed, and if the second dose is more than six months old. Note: The terms “new coronavirus pneumonia” and “new coronavirus pneumonia” mentioned in this article were renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.