The length of time that the third booster protects the body is determined by the type of vaccine: for example, the third booster of the hepatitis B vaccine generally protects the body for 3-5 years; the number of years that the third booster of the new CAPV vaccine protects the body is not known for certain at this time. The third booster shot of Hepatitis B vaccine generally protects for 3-5 years. After the booster injection of hepatitis B vaccine, the human body can produce a certain amount of hepatitis B surface antibodies, which can last for 3-5 years, but the antibody titer may gradually decrease with the extension of time, or even become negative. How long is the protection period of the third booster shot of the new crown vaccine in China cannot be concluded at present. Generally speaking, according to the regulations of WHO, the protection period of booster shots of the vaccine requires more than half a year. The vaccine is safe and effective, but the duration of protection for the third booster dose needs to be monitored. It is recommended to maintain personal hygiene and protective measures, including wearing masks, washing hands frequently, and ensuring social distance. Tips] In this article, “new coronavirus pneumonia” and “new coronavirus pneumonia” have been renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.