There is no authoritative medical information on how many hours you can smoke after vaccination, because vaccination is a process of injecting biological agents into the body to stimulate the immune system to produce antibodies, smoking usually has no effect on the process and the effectiveness of disease prevention. It is recommended to avoid smoking for 48 hours after the vaccination and to decide after 48 hours according to your condition. Some patients may experience a transient adverse reaction after vaccination. The adverse reactions usually vary from person to person due to individual differences. Local skin lesions such as redness, swelling, and pain can usually occur, and some people may also experience systemic symptoms such as fever and malaise. Because tobacco itself and the burning process have some harmful substances, such as nicotine and carbon monoxide, which are irritating to the organism, smoking at this time may cause an increase in the adverse reactions of the patient’s organism. Patients should observe at the vaccination site for 30 minutes after vaccination, and if no uncomfortable symptoms appear, they can leave the vaccination site. However, care should be taken to protect the vaccination site from bacterial infection by keeping it clean and dry and avoiding water. Try not to engage in behaviors that can cause irritation to the body, such as smoking and drinking, and avoid inhaling second-hand smoke, pay attention to a light diet, and also avoid strenuous exercise and overexertion.