If the first injection of Beijing Biological and the second injection of Koxing Zhongwei, the third injection can be inactivated vaccine, but at present it is more recommended to vaccinate with recombinant protein or adenovirus vector vaccine. If the first dose of Beijing Bio and the second dose of KXCV are given, the third dose can be continued with inactivated vaccines, including Beijing Bio, KXCV and Changchun Bio, all of which are inactivated neocoronavirus vaccines. The same type of vaccine can be mixed even if they are from different manufacturers, but they are of the same technical route. However, according to the current recommendation of sequential vaccination, it is more recommended to vaccinate with recombinant protein vaccines such as Anhui Zhifei or adenovirus vector vaccines such as Kangxinuo. A booster vaccination with a different technical route can consolidate the effect of the vaccine and prevent mutated strains such as omicron.