The purpose of this study was to assess the age-appropriate coverage and associated risk factors for the primary vaccination of Polio-containing vaccine (PCV) and measles-containing vaccine (MCV) among children aged 12–23 months using the secondary data from the 2018 Zhejiang provincial coverage survey. Data were gathered by face-to-face interviews with 770 mothers and their children aged 12–23 months using a structured pre-tested Chinese version questionnaire. The Chinese immunisation schedule guideline was used to assess age-appropriate immunisation coverage. The age-appropriate vaccination coverage for PCV1, PCV2, PCV3, and MCV was 88.8 percent, 80.8 percent, 73.6 percent, and 75.7 percent, respectively. The risk factors associated with the age-inappropriate vaccination of PCV 1–3 dose and MCV included the child’s gender, birthplace, living area, maternal education level, immigration status, monthly household income, participation in the pregnant women’s seminar, antenatal care follow-up, and vaccination knowledge.

When compared to current coverage, the percentage of age-appropriate immunisation coverage was low. Age-inappropriate immunizations were linked to modifiable factors.