There is no specific regulation on when the second injection of HFMD vaccine should be given, and it is generally recommended that the time of vaccination should not exceed 1 year of age. Hand, foot and mouth vaccine first injection is generally 6 months after birth, after the first injection of hand, foot and mouth vaccine one month after the earlier the vaccine the stronger the immune effect, the better the protection of the child, so it is generally not recommended to delay the vaccination. If the baby is recently ill with low immune activity, it is recommended to consult with the physician at the vaccination station for communication, and the planned vaccination program can be appropriately delayed, usually the delay time is not recommended to exceed one year of age. HFMD is caused by enteroviruses and can be spread through the digestive tract, respiratory tract and close contact, and is prevalent in children aged 6 months to 5 years. The immune system of infants and young children is not yet fully developed, and the younger they are, the greater the chance of infection. Therefore, it is recommended to follow the doctor’s advice to get vaccinated for the whole period.