Influenza vaccines mainly include influenza virus lysate vaccine and influenza whole virus inactivated vaccine. 1. Influenza virus lysate vaccine: 0.25 ml (for children aged 6 months to 3 years) per 1-time human dose, containing 7.5 μg of hemagglutinin of each influenza virus strain; or 0.5 ml (for adults and children aged 3 years or above), containing 15 μg of hemagglutinin of each influenza virus strain. 2. Inactivated influenza whole virus vaccine: 0.5m or 1.0ml per vial. 0.5ml or 1.0ml per 1-time human dose, containing 15μg of hemagglutinin of each influenza virus strain. Influenza vaccine is used to prevent influenza by stimulating the body to produce immunity against the influenza virus. Patients are advised to consult the local vaccination department for specific matters related to influenza vaccine and to learn about its contraindications and adverse reactions.