Influenza vaccines can be categorized into three types: whole virus inactivated vaccine, cracked vaccine and subunit vaccine. 1. Whole virus inactivated vaccine: The advantage of whole virus inactivated vaccine is that it is more immunogenic and produces good antibody, but the disadvantage is that it has a higher chance of side effects and is not suitable for children under 12 years old. 2. Fracking vaccine: Fracking vaccine retains the antigenic components of the virus and removes the viral nucleic acid and large proteins. The advantage is that the chance of side effects is relatively small and the immunogenicity is retained at a high level, but the disadvantage is that the process is more complicated and requires the use of cracking agents. 3. Subunit vaccine: The subunit vaccine retains only the neuraminidase and hemagglutinin proteins of the influenza virus, and has a single antigenic component. The advantage is that it has fewer side effects and is inexpensive, and the disadvantage is that it is less immunogenic. For influenza vaccination, you can refer to your doctor’s advice to proceed.