Humanitarian Crises, A Roadblock to Global Health Vaccinationand Immunisation Initiatives

Abstract

Background: Humanitarian crises have a significant negative impact on global health initiatives. Humanitarian crises, driven by conflict and natural disasters, result in population displacement, and significantly affect healthcare and routine immunisation services.
Problem: Vaccination and immunisation efforts in crisis-affected areas are hindered by broken logistics and supply chain systems, resulting in delayed
deliveries, and weakened health infrastructure. Population displacement leads to overcrowding, and increased transmission of Vaccine-Preventable Diseases (VPDs). The resultant fragile governance limits coordination between government and humanitarian partners, leading to an increase in zero-dose and under-immunised children.
Aim: This article analyses the mechanisms by which humanitarian crises disrupt vaccines supply chains and coverage, using the Cameroon conflict as a case study, and proposes integrated response strategies.
Method: We conducted a narrative review of peer-reviewed and institutional literature published between 2015 and 2025 on vaccination in humanitarian
and conflict-affected settings. We complemented this review with a qualitative case study using routine immunisation reports, outbreak investigation summaries, program monitoring data, and stakeholder field experiences from the Northwest and Southwest regions of Cameroon between 2019 and 2025. We synthesized findings thematically, focusing on health system disruptions, supply chain constraints, service delivery barriers, and surveillance breakdowns.
Results: We observe broken health systems from armed conflict, leading to compromised delivery of health commodities, a preponderance in unimmunised and under immunised children in conflict laden areas of the world. The direct result is outbreaks, and increased under-5 morbidity and mortality.
Impact: In Cameroon, VPDs have resurged over the past four years, including poliomyelitis, measles, yellow fever, and neonatal tetanus, especially in the
crisis-hit regions, such as the Wabane and Eyumodjock health districts in the Southwest Region. This resurgence is not unique to Cameroon. Other conflictaffected countries report similar findings regarding VPDs. These trends illustrate how insecurity and logistical challenges compromise vaccine delivery and handling, as well as vaccination coverage, thereby threatening immunisation goals.
Conclusion: The interplay between humanitarian crises and immunisation underscores the urgent need to integrate resilience and emergency response into vaccination strategies. Strengthening these systems is critical to improving coverage, protecting vulnerable populations, and advancing progress toward Sustainable Development Goal 3, with vaccination remaining central to health equity.