evidence: In 2019, the global increase in cases was driven by large outbreaks in several countries. Huge outbreaks occurred in DRC and Madagascar during 2018–2019 as a consequence of accumulations of large numbers of measles-susceptible children, which resulted from longstanding extremely low MCV1 coverage, no introduction of MCV2 into the immunization program, and suboptimal SIA implementation. Samoa’s outbreak resulted from a steady decline in MCV1 and MCV2 coverage during 2014–2018, exacerbated by a decline in vaccine confidence after two infant deaths occurred from an error in measles-mumps-rubella vaccine administration (9). Ukraine’s outbreak was the result of low vaccine confidence among health care professionals, low demand from the public, and challenges with vaccine supply, storage, and handling.**** Brazil’s outbreak was caused by previously unidentified immunity gaps, revealed by sustained transmission following multiple measles virus importations from the outbreak in neighboring Venezuela.†††† [...] - World Health Organization. SAGE meeting. Meeting of the Strategic Advisory Group of Experts on Immunization. Geneva, Switzerland; World Health Organization; 2020. https://www.who.int/immunization/sage/meetings/2020/october/SAGE_eYB_Oct2020final.pdf?ua=1 - Isaacs D. Lessons from the tragic measles outbreak in Samoa. J Paediatr Child Health 2020;56:175. CrossRef PubMed - O’Brien K. Report from the director of IVB: building back better for immunization in a COVID-19 world. Meeting of the Strategic Advisory Group of Experts (SAGE) on Immunization, October 5–7, 2020, Geneva, Switzerland. https://www.who.int/immunization/sage/meetings/2020/october/SAGE_Slidedeck_Oct2020-Web.pdf?ua=1