evidence: The COVID-19 crisis has interrupted childhood immunization efforts globally, with potentially deadly consequences [...] The COVID-19 crisis has interrupted childhood immunization efforts globally. Since March 2020, routine childhood immunization services have been disrupted on a scale not seen since the inception of the Expanded Programme on Immunization in the 1970s. More than half (53 per cent) of the 129 countries where data are available reported moderate-to-severe disruptions or a total suspension of vaccination services during March and April 2020. Measles and polio vaccination campaigns, in particular, have been badly hit, with suspended measles campaigns in 27 countries and suspended polio campaigns in 38 countries. At least 24 million people in 21 lower-income countries are at risk of missing out on vaccines against polio, measles, typhoid, yellow fever, cholera, rotavirus, human papillomavirus (HPV), meningitis A and rubella. Moreover, border closures resulting from COVID-19 outbreaks are resulting in potential vaccine shortages in at least 26 low- and middle-income countries.