This report shows that while vaccination is one of the most effective public health interventions—preventing 4–5 million deaths annually—the scale required for COVID-19 immunization far exceeds previous efforts. Unlike traditional campaigns targeting millions of children, COVID-19 vaccination must reach the global adult population—around 6.5 billion people—despite only about 60% of countries having adult immunization systems in place. 

The report highlights that sustaining high vaccination coverage, including potential booster doses, will require unprecedented large-scale efforts across urban and rural areas, addressing challenges in vaccine supply, cold chain logistics, financing, waste management, and public outreach to ensure effective and equitable delivery.