The State of the World’s Children 2023 examines what needs to happen to ensure that every child, everywhere is protected against vaccine-preventable diseases. In the wake of the COVID-19 pandemic, which set back progress in childhood immunization globally, it focuses on the role of poverty, marginalization and gender in determining whether or not children are vaccinated. Drawing on lessons learned during the pandemic and from UNICEF’s decades-long expertise and experience in vaccinating children, it examines the ways in which primary health care can be strengthened to better support immunization services. It looks, too, at concerns around trust in vaccines. And examines a range of innovations in vaccine development and delivery and in financing.