Staying up late before vaccination is not recommended because it may induce acute diseases affecting vaccination, or induce or aggravate adverse reactions, etc. Firstly, staying up late before vaccination may lead to a decrease in one’s immunity, which may easily induce a cold, fever, dizziness and other uncomfortable symptoms, while vaccines, such as measles vaccine and BCG vaccine, cannot be administered during the fever. Secondly, staying up late before vaccination may lead to a decrease in the strength of the immune response generated after the vaccine enters the body, which indirectly affects the vaccination effect and reduces the chance of disease prevention to a certain extent. In addition, some vaccines may increase the chance of adverse reactions in themselves after staying up late for vaccination, or aggravate uncomfortable symptoms, such as acute allergic reactions like fever, dyspnea and laryngeal edema, or chronic reactions like rash, diarrhea and fever. As you can see, it is not recommended to stay up late before and after vaccination. In addition, after the vaccination, it is important to observe the vaccination site for 30 minutes and leave after there is no adverse reaction. Thereafter, it is also necessary to avoid smoking, drinking alcohol, eating spicy food, etc. It is recommended to eat a light diet, eat more fresh vegetables and fruits, drink more water, pay attention to rest, and avoid strenuous exercise, etc. In addition, from the health point of view, the general daytime activities, rest at night, work and rest combination. Staying up late for a long time will disrupt the biological clock and have adverse effects on the body, and in serious cases, there may be different degrees of effects on vision, blood vessels, skin and brain, such as vision loss, hardening of blood vessels, rough skin, memory loss, etc. Therefore, it is not only not recommended to stay up late before and after vaccination, but also to live a regular life and reduce or avoid staying up late.