Ikilezi G, Micah AE, Bachmeier SD, et al. - Despite the known value of childhood immunization, great lacunae remains in global access to vaccines. In view of the observation that in many health systems, inadequate vaccine coverage is due to supply-side constraints, researchers herein performed comprehensive analysis of the funding for immunization. Estimates of funding for immunization disaggregated by the source of funding and the type of activities were generated to describe the funding landscape for immunization and inform policy making.

• This financial modelling study was conducted using data from National Health Accounts, the WHO–UNICEF Joint Reporting Forms, comprehensive multi-year plans, databases from Gavi, the Vaccine Alliance, and the Institute for Health Metrics and Evaluation's 2019 development assistance for health database.

• Annual spending on immunizations from 2000 to 2017 was determined for 135 low-income and middle-income countries (as determined by the World Bank). Funding for immunization totaled US$112.4 billion.

• The largest source of funding consistently remained government spending aggregated across all low-income and middle-income countries, providing between 60% and 79.3% of total immunization spending each year.

• In 2017, the largest share of total immunization spending was provided by the development assistance (69.4% [64.6–72.0]; $630.2 million) in low-income countries and territories.

• Across the 135 countries, higher vaccine coverage and increased government spending on immunization were recorded over time, although there appeared a decrease in vaccine coverage over time in some countries, predominantly in Latin America and the Caribbean and in sub-Saharan Africa, while spending increased.

• Findings overall suggest persistence of many challenges and the necessity for dedication and commitment to ensure sustainment of the progress made in the previous decade and its advancement in the next decade for the Immunization Agenda 2030.