After the injection of yellow fever vaccine, the following points need to be noted: First, allergic reactions: it can cause multiple organ failure in severe cases, so pay attention to the changes in the condition and stay in the observation room for at least half an hour after the injection. Second, adverse reactions at the injection site: such as edema, necrosis, pain, masses, etc. Do not take a shower within 24 hours to avoid local infection. Third, the emergence of side reactions: such as fever, headache, muscle aches, etc., you can give antipyretics and other symptomatic treatment, if there is a change in consciousness, severe headache, jet vomiting, etc., to promptly seek medical attention, especially in patients with immunodeficiency such as AIDS, there may be lethal encephalitis, be especially cautious. Fourth, people with chicken and egg allergies should not be vaccinated: because the yellow fever vaccine is cultured in chicken embryos by passages.