It is not recommended to drink alcohol after vaccination. This is because drinking alcohol can increase the incidence of adverse reactions to the vaccine and, in patients who are already experiencing adverse reactions, alcohol can also make them worse. In addition, the symptoms of discomfort caused by alcohol and adverse reactions caused by vaccines have similar manifestations and can easily cause confusion. Alcohol can accelerate blood circulation, dilate capillaries, increase capillary permeability, and increase blood extravasation, which can easily lead to redness, swelling, pain, hard nodules, itching, and oozing at the injection site. In addition, systemic adverse reactions such as dizziness, headache, fever, muscle aches, vomiting and diarrhea may occur in a small number of people after vaccination, and some of the above symptoms may also occur or worsen after drinking alcohol. It is impossible to determine whether the symptoms are caused by alcohol or the adverse reactions caused by the vaccine itself, which may lead to misjudgment or misdiagnosis. There are many types of vaccines, and the principle of all of them is to stimulate the body to have an immune response after injection and produce antibodies to prevent diseases. If you drink alcohol after vaccination, it will affect the human immune system to a certain extent, which may indirectly affect the production of antibodies after vaccination and thus the effectiveness of disease prevention. For these reasons, it is recommended that alcohol should not be consumed within 3 days of vaccination.