**2. Major Initiatives to Tackle Inequality in Immunization**

As part of efforts to restore progress and tackle inequality, in 2020, the World Health Assembly endorsed the Immunization Agenda 2030 (IA2030) [9]. IA2030 sets forth an "ambitious, overarching global vision and strategy for vaccines and immunization for the

**Citation:** Nambiar, D.; Hosseinpoor, A.R.; Bergen, N.; Danovaro-Holliday, M.C.; Wallace, A.; Johnson, H.L. Inequality in Immunization: Holding on to Equity as We 'Catch Up'. *Vaccines* **2023**, *11*, 913. https:// doi.org/10.3390/vaccines11050913

Received: 19 April 2023 Revised: 21 April 2023 Accepted: 24 April 2023 Published: 28 April 2023

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decade 2021–2030" [9]. IA2030- s third Strategy Priority places emphasis on coverage across subgroups of gender, age, location, or socioeconomic status and promotes principles of people-centredness and country ownership for processes that are premised on partnership and guided by data. Realizing the IA2030 vision—a world where everyone, everywhere, at every age fully benefits from vaccines for good health and well-being—is aligned with the Sustainable Development Goal (SDG) imperative of "leaving no one behind" [9]. Indeed, immunization is central to achieving the health-specific SDG (SDG3), and, furthermore, contributes to 14 of the 16 other SDGs [10].

Equity is a major priority area for Gavi, the Vaccine Alliance. Gavi, established in 2000 to improve access to vaccines among children in the poorest countries, has supported countries in the provision of vaccines to 981 million children in 77 countries through routine immunization programmes, and an additional 1.4 billion vaccinations through campaigns [11]. Gavi's current 2021–2025 strategy builds on this work, addressing within country equity as an organizing principle "with a high ambition to reduce the number of under-immunized children and an intensified focus on reaching the unreached" [12]. This includes additional support for countries such as the Identify–Reach–Monitor–Measure– Advocate (IRMMA) framework, a new Equity Accelerator Fund and Learning Hub [13].

Another noteworthy initiative is the Equity Reference Group for Immunization (ERG), an action-oriented thinktank consisting of senior experts in global health working with WHO, Gavi, the World Bank, the Bill and Melinda Gates Foundation, and UNICEF; academics in critical topics such as metrics, gender, and health systems development; and senior leaders from ministries of health. The ERG has four priority thematic areas: urban poor areas; remote rural areas; children affected by conflict; and gender-related inequities and barriers to immunization [14].
