Abstract:

Objective To understand the vaccination rate of age-eligible children on the expanded program on immunization（EPI） in migrant concentration areas of Tianjin，identify weaknesses in routine management，and provide a scientific basis for formulating immunization strategies. Methods From February to November 2024，initial self-inspection was carried out at the sub-district or township level，followed by two-tier quality control involving verification at the district level and municipal spot checks. Random household interviews were set up in streets（townships） in selected migrant concentrated areas to investigate vaccination rate on the EPI among age-eligible children. Results At the self-inspection stage，the rates of card registration，certificate issuance，and card-certificate consistency were 99.84%，99.81% and 99.89%，respectively. In the district re-checking and municipal spot-checking stages，all above three indicators reached 100.00%. Except for the slightly lower qualified vaccination rates of MenA+C2 and Var2（94.72% and 94.87%） during the sub-district/township self-inspection stage，that of Var2（94.97%） during the district-level re-check stage，and that of DTP4（93.96%） during the municipal spot-check stage，all other doses of EPI vaccines achieved a qualified vaccination rate of ≥95%. Except for MMR2，MenA1，JEV-L1，and DT，there were no statistically significant differences in vaccination rates among the two-level surveys（allP>0.05）. During the municipal spot-check of 182 children，11 doses had not been administered；contraindications accounted for 72.73% of these missed doses. Among 51 doses classified as non-qualified，98.04% were due to delayed administration. Conclusion The vaccination rate of the EPI in migrant concentration areas of Tianjin remains at a high level. Further efforts are needed to enhance the refined management of vaccination services and further improve the quality of the EPI work. The survey method and quality control model，which combine self-inspection at the grassroots level and quality control at the higher level，can also serve as a reference for evaluations in similar regions.

Key words: Expanded program on immunization, Vaccine, Vaccination rate, Children, Survey, Quality control