There is no four-dose (basic immunization) NeoCrown vaccine, only one-dose, two-dose and three-dose NeoCrown vaccines.
1. 1-dose New Crown Vaccine: Adenovirus-vectored New Crown Vaccine, basic immunization requires only one dose. After the first dose, a second booster dose is required after a 6-month interval.
2. Two doses of New Crown Vaccine: Inactivated New Crown Vaccine, basic immunization requires two doses. The first and second shots should be given 21-56 days apart. After the basic vaccination, the third booster shot can be given at an interval of 6 months.
For the third booster shot, you can get either the inactivated New Crown vaccine, the recombinant subunit New Crown vaccine, or the adenovirus-vectored New Crown vaccine. The recombinant subunit vaccine or the adenovirus-vectored vaccine is a sequential method of vaccination.
3. Recombinant subunit vaccine: For recombinant subunit vaccine, three doses are required for primary immunization. All three shots need to be given one month apart, and the vaccination program is 0, 1, and 2 months, and no booster shots are needed after the whole vaccination.