Changes in childhood vaccine hesitancy during the COVID-19 pandemic: a retrospective study based on data from Turkey.

BACKGROUND: Vaccine refusal is a growing public health concern, threatening herd immunity and the control of vaccine-preventable diseases. The COVID-19 pandemic has influenced healthcare delivery and vaccine refusal behavior as a proxy for vaccine hesitancy. This study aimed to assess changes in childhood vaccine refusal behavior during the pandemic in Turkey. METHODS: We conducted a retrospective observational study including 2,786 children born between 2017 and 2022 who reached 24 months of age and had complete vaccination records from primary healthcare. Children were categorized as pre-pandemic or post-pandemic based on birthdate. Data on vaccine refusal type, timing, and frequency were collected. Statistical analyses included chi-square tests, with p < 0.05 considered significant. RESULTS: Overall, 3.7% (n = 102) of children had at least one vaccine refusal. Refusal rates were 3.9% before and 3.4% after the pandemic onset, with no significant difference (p = 0.474). However, the median age of first refusal shifted from 12 months pre-pandemic to 1 month post-pandemic. Vaccines given after one year (e.g., MMR, varicella, Hepatitis A) were more frequently refused pre-pandemic, whereas those scheduled in infancy were more often refused post-pandemic. Live vaccines and later doses in multi-dose schedules had the highest refusal rates. Early-onset refusals were strongly associated with multiple vaccine refusals (p < 0.01). CONCLUSION: While overall refusal rates remained stable, the timing of hesitancy shifted to earlier infancy during the pandemic. These findings emphasize the need for targeted parental education and early communication strategies to sustain vaccine coverage and prevent resurgence of vaccine-preventable diseases.