It is not recommended to stay up late after the New Crown vaccine, especially if you have just received the New Crown vaccine. Staying up late may cause mild symptoms of fever, fatigue, diarrhea, or even adverse reactions such as rashes, and may have an effect on the effectiveness of the vaccine. The vaccine is a vaccine that acts on the human immune system. It takes time for the body to produce protective antibodies through immune response after vaccination, and only a good physiological state can better perform its protective effect. Staying up late may cause a decrease in resistance and make the body more susceptible to external bacteria and viruses, thus burdening the immune system and affecting the effectiveness of the vaccine; it may even induce or aggravate adverse reactions to the vaccine, which may cause fever, nausea, vomiting, and even breathing difficulties in severe cases. Therefore, it is recommended that people who have just received the new vaccine should get enough rest, eat a nutritious and light diet, avoid stimulating foods such as seafood, chili, cold drinks and fatty meat, and avoid drinking alcohol and strenuous exercise as much as possible to help the vaccine work best. In addition, you should stay for 30 minutes after vaccination to allow for timely intervention in case of adverse reactions. You should also pay attention to keeping the injection site dry and hygienic, and avoid bathing on the day of vaccination to avoid contaminating the needle hole and causing infection.