It is recommended that patients should preferably use the same manufacturer’s vaccine for vaccination to ensure that the vaccine can have the best effect, but if the conditions of the vaccinator do not allow, they can also choose to receive the same type of vaccine and the same dosage form from two manufacturers to have less impact on the vaccine effect. There are many types of vaccines, such as inactivated vaccines, live attenuated vaccines, toxoids, subunit vaccines, peptide vaccines, genetically engineered vaccines, DNA vaccines, etc. If the source of vaccines is not sufficient, some vaccines can be selected from different manufacturers, e.g., the first dose of a new crown vaccine with inactivated vaccine from one manufacturer and the second dose with inactivated vaccine from another manufacturer is usually possible without excessive influence on the effect. If the vaccine components of different manufacturers are also different, mixing vaccination is generally not allowed and may have some effect on the vaccine effect or even induce serious adverse reactions. For example, if the first dose of the new crown vaccine is administered with an inactivated vaccine of a certain manufacturer, the other dose cannot be replaced with a DNA vaccine of another manufacturer, etc. Since there are many types of vaccines that require more than two doses, including rabies vaccine, hepatitis B vaccine, etc., it is recommended that the recipient contact the relevant medical structure to confirm whether the two manufacturers’ vaccines can be mixed in order to avoid receiving different types of vaccines and thus other adverse reactions. If patients experience minor adverse reactions such as dizziness, nausea, vomiting, fever, etc. after vaccination, these are usually normal physiological reactions that can be relieved on their own after a period of rest and may not be due to the effects of mixing vaccines, so patients need not worry too much. However, if patients have more serious adverse reactions, such as persistent fever and coma, it is recommended to go to a regular hospital for consultation in time to avoid other adverse reactions.