Abstract

Objective: This study aimed to examine vaccine refusal cases reported in Bilecik province between 2015 and 2024 by analyzing rejected vaccine types, vaccination status, reasons for refusal, and demographic characteristics.

Methods: This cross-sectional epidemiological study evaluated 692 vaccine refusal cases reported to the Bilecik Provincial Health Directorate between 2015 and 2024. Data were obtained from official records submitted by family health centers. Recorded variables included year of refusal, age, sex, district of residence, type of vaccine rejected, vaccination status, and reasons for refusal. Vaccine refusal prevalence was calculated according to annual live birth data and age groups. Data were analyzed using IBM SPSS version 18.0; numerical variables were summarized as medians, and categorical variables as frequencies and percentages.

Results: Of the cases, 50.6% were male and 49.4% were female; the median age was 1 year. Among vaccine refusal cases, 37.4% resided in the city center, whereas 62.6% lived in districts or towns. The most frequently rejected vaccines were diphtheria-acellular pertussis-tetanus-inactivated poliovirus-Haemophilus influenzae type b vaccine (DTaP-IPV-Hib), measles-mumps-rubella (MMR) vaccine, and pneumococcal conjugate vaccine (PCV). Parental decision was the most common reason for refusal (86.0%). Vaccine refusal prevalence increased from 0.3% in 2015 to >8% in 2024. The highest number of refusals occurred in the 0–4-year age group.

Conclusion: Vaccine refusal cases in Bilecik province increased substantially over the study period, particularly in early childhood. These findings indicate the need for targeted local immunization strategies.