Common adverse reactions after vaccination include pain, redness and swelling at the vaccination site, low-grade fever and so on. Influenza vaccine is a kind of vaccine for preventing epidemic cerebrospinal meningitis. At present, there are many types of vaccines for influenza, usually including group A influenza polysaccharide vaccine, group A+C influenza polysaccharide vaccine, group A+C influenza conjugate vaccine, and group A+C+Y+W135 influenza polysaccharide vaccine. There are some differences in the symptoms associated with each type of vaccination. Taking the most common group A polysaccharide vaccine as an example, certain adverse reactions will often be manifested after vaccination, such as mild, localized pain and redness at the site of vaccination, occasional headache, dizziness and transient low-grade fever. Generally, the adverse reactions of vaccination are relatively mild, but when the vaccinated people are allergic to vaccine components, suffer from organic diseases of heart, liver and kidney, active tuberculosis and acute infectious diseases, or have fever, they need to pay attention, and such people should not be vaccinated. The vaccination may induce more serious shock or even liver and kidney damage.