2. Moderate exercise after vaccination does not reduce human immunity. However, it is recommended to avoid strenuous exercise, which is to avoid physical discomfort caused by excessive exercise.

3. The recommended immunization program for COVID-19 vaccine is 2 shots with an interval of at least 14 days, and the inoculation site is deltoid muscle of upper arm. Generally speaking, the vaccine can achieve a good protection effect after two injections 14 days, and the protection time of the vaccine.

4. COVID-19 was discovered just over a year ago, and the vaccine has just been developed. It's hard to say how long it can last after vaccination, and it will take some time to observe how long the antibody can last. Judging from the current data, it is no problem to guarantee for half a year.