In general, three year olds can get the New Crown vaccine. The safety profile of the vaccine is the same as that of adults, and the production of antibodies does not differ from that of adults. Therefore, 3-year-olds in good health can receive the vaccine. After a three-year-old child has received the New Crown vaccine, he or she needs to be observed for 30 minutes to avoid serious adverse reactions, such as allergies, which need to be dealt with promptly. Meanwhile, pay attention to keep the injection site dry, eat a light diet, drink more water and eat less stimulating food. The type of New Crown vaccine for three-year-olds is inactivated, and the interval between the first and second shots of New Crown vaccine is greater than 3 weeks, but should not exceed 8 weeks. In case of contraindications such as fever and acute illness in the body, the New Crown vaccination is suspended.