Interventions to Vaccinate Zero-Dose Children: A Narrative Review and Synthesis

Abstract

Zero-dose children, or children who have not received any routine vaccination, are a priority population for global health policy makers as these children are at high risk of mortality from vaccine-preventable illnesses. We conducted a narrative review to identify potential interventions, both within and outside of the health sector, to reach zero-dose children. We reviewed the peer-reviewed and grey literature and identified 27 relevant resources. Additionally, we interviewed six key informants to enhance the synthesis of our findings. Data were organized into three priority settings: (1) urban slums, (2) remote or rural communities, and (3) conflict settings. We found that zero-dose children in the three priority settings face differing barriers to vaccination and, therefore, require context-specific interventions, such as leveraging slum health committees for urban slums or integrating with existing humanitarian response services for conflict settings. Three predominant themes emerged for grouping the various interventions: (1) community engagement, (2) health systems’ strengthening and integration, and (3) technological innovations. The barriers to reaching zero-dose children are multifaceted and nuanced to each setting, therefore, no one intervention is enough. Technological interventions especially must be coupled with community engagement and health systems’ strengthening efforts. Evaluations of the suggested interventions are needed to guide scale-up, as the evidence base around these interventions is relatively small.

Status of Routine Immunization Coverage in the World Health Organization African Region Three Years into the COVID-19 Pandemic

“…To this end, the "Big Catch-up" initiative [29], an essential immunization recovery plan for 2023 and beyond, represents a unique opportunity for catching-up children who have missed immunization, restoring immunization services to the pre-pandemic levels, and strengthening these services to achieve the targets of Immunization Agenda 2030. However, reaching zero-dose children requires context-specific interventions to overcome barriers to vaccination that are multifaceted and nuanced to each setting [30]. In addition, mechanisms need to be in place to reduce drop-out in an equitable manner so that children are not only reached once, but get all vaccines they need [31].…”

Spatial distribution of zero-dose children in Ethiopia: evidence for a targeted intervention from a large-scale cross-sectional evaluation survey

“…Reaching zero-dose children is hampered by a variety of complex obstacles unique to each setting ( 41 ). The problem can be addressed by designing-context specific interventions including strengthening horizontal integration of immunization services with other maternal & child health services such as antenatal and postnatal care, sick childcare, nutritional screening, growth monitoring, and family planning; empowering women; strengthening outreach campaigns, supplementary immunization activities (SIAs); Periodic Intensification of Routine Immunization (PIRI); strengthening outreach and static immunization services; providing incentives for health staff; bolstering immunization budget; planning to establish Men Development Army to promote engagement of men in maternal and child health services ( 20 , 21 , 40 ).…”

“…Reaching zero-dose children is hampered by a variety of complex obstacles unique to each setting (41) (20,21,40).…”

Status of Routine Immunization Coverage in the World Health Organization African Region Three Years into the COVID-19 Pandemic

“…To this end, the “Big Catch-up” initiative [ 29 ], an essential immunization recovery plan for 2023 and beyond, represents a unique opportunity for catching up children who have missed immunization, restoring immunization services to the pre-pandemic levels and strengthening these services to achieve the targets of the Immunization Agenda 2030. However, reaching zero-dose children requires context-specific interventions to overcome barriers to vaccination that are multifaceted and nuanced to each setting [ 30 ]. In addition, mechanisms need to be in place to reduce drop-out in an equitable manner so that children are not only reached once but receive all the vaccines they need [ 31 ].…”