Nadine Müller, Apollinaire F Mahafeno, Andrinirina C Rasolofondraibe, Gabrielle T Andriantiantsoa, Andry Ns Randrianirisoa, Elgiraud Ramarosaiky, Fanjatiana Rlr Rakotoarisoa, Fanilo N Valitera, Zavaniarivo Rampanjato, Miora M Andriamanjay, Elsa Niritiana Rajemison, Riana S Ramanantsoa, J Emmrich, Lara M Press, Christian H Ravelomahafaly, Maurin Mananatitra
Problem: Madagascar has a high number of unvaccinated (zero-dose) children. In 2023, an estimated 74% received any dose of the diphtheria-tetanus-pertussis (DTP) vaccine. In southern Madagascar, service gaps, poverty, drought and limited access leave many children unreached by routine immunization. Approach: (lowest administrative unit). Digital tools supported data collection, validation and CHW incentive payments. Local setting: The southern regions of Atsimo Andrefana, Androy and Anosy have about 3.7 million inhabitants, most in remote areas. Health indicators lag behind national averages. Volunteer CHWs lack training, supervision and financial protection, resulting in incomplete population data and weak microplanning. Relevant changes: , 81% (3538/4347) completed registry updating. Overall, 58% (213 173/368 227) of the children enumerated had no documented DTP dose. District-level prevalence of no-dose children ranged from 25% (7956/32 015) to 86% (14 989/17 445). These data guided zero-dose mapping and targeted outreach. As of March 2026, 42 700 zero-dose children had received DTP vaccination, surpassing the programme target ahead of schedule. Lessons learnt: Locally led partnerships and CHW engagement, supported by simple digital tools and transparent financial mechanisms, produced actionable data on zero-dose children. Prior agreement on zero-dose case definitions ensures compatibility with national reporting.