Why Reaching Zero-Dose Children Holds the Key to Achieving the Sustainable Development Goals

Abstract

Immunization has one of the highest coverage levels of any health intervention, yet there remain zero-dose children, defined as those who do not receive any routine immunizations. There were 18.2 million zero-dose children in 2021, and as they accounted for over 70% of all underimmunized children, reaching zero-dose children will be essential to meeting ambitious immunization coverage targets by 2030. While certain geographic locations, such as urban slum, remote rural, and conflict-affected settings, may place a child at higher risk of being zero-dose, zero-dose children are found in many places, and understanding the social, political, and economic barriers they face will be key to designing sustainable programs to reach them. This includes gender-related barriers to immunization and, in some countries, barriers related to ethnicity and religion, as well as the unique challenges associated with reaching nomadic, displaced, or migrant populations. Zero-dose children and their families face multiple deprivations related to wealth, education, water and sanitation, nutrition, and access to other health services, and they account for one-third of all child deaths in low- and middle-income countries. Reaching zero-dose children and missed communities is therefore critical to achieving the Sustainable Development Goals commitment to "leave no one behind".

Keywords: Immunization Agenda 2030; equity; multiple deprivation; underimmunized children; zero-dose children.

Figure 1

Annual number of zero-dose children and non-zero-dose underimmunized children globally, 2010–2021. Data source: WHO/UNICEF Estimates of National Immunization Coverage (WUENIC), July 2022 [8].

Figure 2

Potential incremental future deaths averted in 57 Gavi-supported countries through routine immunization, 2021–2025. Analysis based on Vaccine Impact Modeling Consortium impact ratios and immunization coverage as estimated in the WUENIC July 2021 release, ignoring the impact of maintaining coverage at 2020 levels and assuming Gavi 5.0 targets are met.