Substantial delays in care-seeking for post-vaccination abscesses: a threat to infant health and immunization trust in Timor-Leste

Background Adverse events following immunisation (AEFI), such as injection-site abscesses, represent a critical but often neglected link in the immunisation cascade, especially in low-resource settings. While systemic barriers to healthcare are widely documented, quantitative evidence on how these barriers directly impact care-seeking for AEFIs—and consequently threaten immunisation program credibility—remains limited. This study examined care-seeking delays for abscesses following Hepatitis B birth dose (HepB-BD) administration in Timor-Leste as a case study of this global challenge. Methods This descriptive cross-sectional study was conducted using the 2024 AEFI surveillance line list of Timor-Leste. All reported cases of abscesses in infants (0–12 months old) following HepB-BD were included in this study. The primary outcome was care-seeking delay, defined as the number of days between the caregiver's notice of the abscess and the first formal healthcare consultation. Data were analysed using descriptive statistical methods. Results Among 41 reported cases, the median care-seeking delay was 17 days (range: 1–44 days). Only 36.6% of caregivers sought care within 10 days, whereas 43.9% delayed care-seeking beyond 20 days. Less than half of the infants (46.3%) received HepB-BD within 24 hours of birth. Conclusion The prolonged delays observed underscore a critical failure point in the immunisation continuum within fragile health systems, where logistical and financial barriers overwhelm caregivers’ decision-making. This study provides quantitative evidence that AEFI management is not merely a clinical concern but a pivotal trust-building interface between communities and health systems. Interventions must integrate active community education, healthcare worker training in AEFI communication, and tangible support to overcome systemic access barriers, a strategy relevant for similar low-resource settings globally.