[Factors associated with timely vaccination of pertussis-containing vaccines in children born from 2019 to 2023, Shanghai].

To analyze factors associated with timely vaccination of pertussis-containing vaccines in children born in Shanghai from 2019 to 2023. Children born in Shanghai between 2019 and 2023 were selected using a stratified random sampling method, and their vaccination data were obtained from the Shanghai Vaccine Management and Vaccination Service Information System. The vaccination rates, timely vaccination rates, and the proportions of diphtheria-tetanus-acellular pertussis-haemophilus influenzae type b combination vaccine (DTaP-Hib) and diphtheria-tetanus-acellular pertussis-inactivated poliovirus-haemophilus influenzae type b combination vaccine (DTaP-IPV-Hib) for the substitution of diphtheria- tetanus-acellular pertussis vaccine (DTaP) were calculated. Also, the factors associated with timely vaccination rate was analyzed with multivariate logistic regression analysis. The average vaccination coverage rate of pertussis-containing vaccines in children born in Shanghai from 2019 to 2023 ranged from 94.71% to 99.53%. There were significant differences in the vaccination coverage of the 1-4 doses of pertussis-containing vaccines among children born in different years (all <0.05), but no gender and area specific significant differences were observed (all >0.05). Non-national immunization program (non-NIP) vaccines were used to substitute DTaP vaccines in some children, with the proportion of DTaP-IPV-Hib vaccine accounting for 50.11%-52.69% and the proportion of DTaP-Hib vaccine accounting for 27.22%-28.43%. The proportions of DTaP-Hib and DTaP-IPV-Hib for the substitution of DTaP had increasing trends over the years. The overall timely vaccination rate of pertussis-containing vaccine vaccination was 84.09%. Analysis on the factors affecting the timely vaccination rate showed that the rate gradually decreased with the increase of the doses. Children who received the self-paid quadrivalent or pentavalent vaccines were less likely to have vaccination delays. Birth year had a significant impact on the timely vaccination rate, while the area had less impact. Additionally, the timely vaccination rate was also influenced by the degree of non-pharmaceutical intervention measures. The substitution of pertussis- containing vaccines with non-NIP vaccines was common in Shanghai. The coverage and timeliness of pertussis-containing vaccine vaccination were relatively high. The timely vaccination rate was significantly associated with gender, dose, vaccine type, and the degree of non-pharmaceutical interventions. There was a certain proportions of delayed and missed vaccinations, and it is necessary to pay attention to children who are not vaccinated timely and conduct high-quality catch-up vaccination to ensure timely and complete vaccination of pertussis-containing vaccines.