Diminished Hepatitis B Antibody Response in Pediatrics With Type 1 Diabetes; the Need for Revaccination Protocol: A Case‐Control Study

Background and Aims Hepatitis B virus (HBV) infection is a significant chronic infection in pediatric patients. Vaccination induces production of anti‐Hepatitis B surface antibodies, which serve as markers of protective immunity. Given the long‐term risks of cirrhosis and hepatocellular carcinoma during adulthood, this study aimed to assess and compare seroprotection between children with type 1 diabetes mellitus (T1DM) and nondiabetic participants. Methods In this case‐control study, 127 children with T1DM and 124 controls, all in a healthy immune state and fully vaccinated against HBV, were recruited from Shiraz University pediatric endocrinology clinics. Exclusion criteria included immunosuppression, incomplete vaccination, or hepatitis history in the child/family. Ethical approval was obtained from Shiraz University of Medical Sciences. Comparisons of sex, age, antibody titers, and diabetes indices used appropriate inferential tests; odds of inadequate antibody titers were assessed by logistic regression. Results Considering an antibody titer of 10 mIU/mL as adequate, the non‐protection rate was 54.3% (95% CI: 45.3%–63.2%) in diabetic individuals and 28.2% (95% CI:20.5%–37.0%) in non‐diabetics. In a multivariable model controlling for time from vaccination, time from vaccination (OR = 1.26, 95% CI: 1.06–1.49, p < 0.001), and diabetes status (OR = 2.34, 95% CI: 1.33–4.14, p = 0.002) contributed to inadequate antibody titers. Sex, glycemic control, and disease duration over 1 year had no significant effect. Conclusion Children with type 1 Diabetes Mellitus exhibited lower anti‐HBs antibody titers compared to their nondiabetic counterparts, with no association found with sex or glycemic control. The timing of vaccination and diabetes status should be considered when evaluating immune responses to HBV vaccination in children.