Vaccination is not recommended during cold and flu, so as not to affect the recovery of the disease. When the patient’s immunity is low during a cold, it is easy to cause viral and bacterial infections, and the main ingredient of the vaccine is inactivated viruses or bacteria, which are foreign substances to the body and may contain some toxins or viruses. Administering a vaccine in the presence of a cold can result in viral or bacterial infection of that vaccine, which may cause fever and other complications. For this reason, vaccinations are not recommended during a cold and can usually be given about a week after the symptoms of a cold have subsided. During the cold period, you should pay attention to rest, avoid exertion, and eat a light diet, avoiding oily as well as spicy and irritating foods. In addition, drinking a moderate amount of water during a cold can promote the excretion of toxins.