Supply-Side Bottlenecks of Newly Introduced and Second-Year-of-Life Vaccines in Malawi: From Vaccine Availability to Delivery

Introduction: Existing evidence on why children miss vaccines after infancy has focused on the demand side, that is, on the attitudes and circumstances of caregivers. The supply side, meaning the system’s capacity to make vaccines available, accessible, and deliverable, has received less attention, even though it determines whether a willing caregiver can be served. This study examined the supply-side determinants of second-year and newer vaccine uptake in Malawi through a coverage-cascade and bottleneck analysis. Methods: A mixed-methods study drew on one cross-sectional survey with a caregiver component (n = 1177) and a frontline health worker component (n = 453), a data quality assessment of stock records at 37 sites, and key-informant interviews and focus group discussions at community, facility, district and national level. Findings were organised through the Tanahashi coverage framework, which follows the steps from the availability of commodities and staff, through geographic access, to service contact and coverage. Supply-side constraints on uptake were profiled at each step and set against the coverage achieved for each antigen. Results: Coverage fell across the antigen sequence, from 93.4% for the second dose of measles–rubella vaccine and 91.2% for the second dose of inactivated polio vaccine, to 74.6% for the typhoid conjugate vaccine and 61.4% for the HPV vaccine. Stock management was largely in place. Stock records were maintained and reconciled at 35 of 37 assessed sites, and only 4.5% of caregivers who gave a reason for a missed dose named a stockout. Yet 24.8% (95% CI 21.2–28.8) of caregivers (district range 20–35%) reported having ever been turned away because a vaccine was unavailable. Human-resource readiness was weaker, with over half of frontline workers never receiving refresher training. Between 9% and 37% of caregivers, by district, lived more than five kilometres from a facility. Transport was the constraint on mobilisation most often named by health workers (72%). Interviews described outreach as dependent on fuel and external funding. Stock systems worked on paper, but vaccination was less reliably available when caregivers attended. Constraints appeared at this point of contact, in the continuity of outreach and in the maintenance of frontline capacity. National respondents placed these constraints within a financing system that is partly donor-dependent and fragmented across separate partner plans. Conclusions: The supply system delivered the established second-year antigens well. It was less consistent for the newer ones and at the point of contact. Sustaining uptake will require protecting stock at the point of need, resourcing outreach, maintaining frontline capacity, and adapting supply for the newer vaccines.