You cannot get the third New Crown booster shot without being 18 years old, as explained below: The third booster shot of the new crown vaccine, also known as the booster immunization shot, is a vaccine dose that is administered after the completion of the previous doses of the new crown vaccine and supplemented according to the fading of antibodies to maintain the body’s resistance to the virus. At this stage in China, most of the inactivated New Crown Vaccine is given in 2 doses throughout the vaccination, while some are given in only one dose. Depending on the degree of decline in the body’s antibody level, another injection will be administered. The conditions for the third vaccination of the new crown vaccine are that people over 18 years of age who have completed two doses of inactivated vaccination and the second dose has been completed for 6 months, so people under 18 years of age are not allowed to take the third vaccination of the new crown vaccine.