You can drink coffee in moderation after the vaccination, but since more rest and avoid overexertion are emphasized after the vaccination, drinking large amounts of coffee is generally not recommended. In addition, it is best not to drink it within 30 minutes of staying for observation after vaccination. Although coffee will not affect the effect of the vaccine, the immune function of the body will be temporarily affected after the vaccination, and coffee may aggravate the adverse reactions caused by the vaccine. Coffee in general does not significantly affect the immune system and does not reduce the effectiveness of the vaccine. However, the main components in coffee, such as caffeine and adenosine acid, have the effect of increasing neuroexcitability and dilating blood vessels, and large amounts of coffee may cause patients to experience abnormal excitement, insomnia, headache, dizziness and other uncomfortable symptoms. Vaccines work by acting on the immune system of the human body, and the immune function may be temporarily disrupted after vaccination, which may cause dizziness, nausea and other side effects, and the superposition of the two may cause more serious discomfort to patients. In addition to coffee, smoking, drinking, eating spicy and seafood stimulating foods, and strenuous exercise after vaccination may aggravate the adverse reactions caused by the vaccine, so it is emphasized that patients should eat lightly and get sufficient rest after vaccination. In addition, coffee is an excitatory drink, and long-term consumption in large quantities may lower mood and affect sleep quality, so it is recommended to reduce consumption as much as possible in daily life.