Polio vaccine refers to the inactivated polio vaccine, which is usually injected into the middle of the anterior lateral thigh in infants and children, and into the deltoid muscle in children, adolescents and adults. The inactivated polio vaccine is a clear, colorless liquid and is administered by intramuscular injection, with the first two doses generally recommended as injections. The best site for intramuscular injection in infants and children is the mid anterolateral thigh, while the deltoid muscle is usually chosen for injection in children, adolescents and adults. These areas are relatively rich in muscle distribution and are relatively safe for drug absorption. In some people, after receiving inactivated polio vaccine, local reactions such as pain, erythema and hard nodules may occur at the injection site, and the health condition of the vaccinated person needs to be closely monitored. For patients with fever or acute illness period, and those who are receiving immunosuppressant treatment, this vaccination should be postponed to avoid aggravating the adverse reactions of the vaccine, or reducing the effectiveness of the vaccine. It is recommended that people who are vaccinated with inactivated polio vaccine should be vaccinated by healthcare professionals at sites appropriate to the actual situation.