The last dose of 13-valent pneumonia vaccine should be given at the latest when the baby is 12-16 months of age, and the purpose of the last dose is mainly for booster immunization. 13-valent pneumonia vaccine is mainly used for infants and children under 2 years of age who need 4 doses, 3 basic immunizations at 2 months, 4 months and 6 months of age respectively, and the last one at 12-16 months of age. The 13-valent pneumonia vaccine may cause adverse reactions after the injection, including redness, swelling, fever, loss of appetite, rash and dermatitis around the body, etc. The adverse reactions are mild and can be fully recovered in 1-3 days.