WHO and UNICEF use data from 1) administrative coverage (calculated by dividing the number of vaccine doses administered by the estimated target population reported annually), 2) country estimates,¶ and 3) vaccination coverage surveys to estimate MCV1 and second dose MCV (MCV2) coverage through routine immunization services (i.e., not mass campaigns).** During 2000–2010, estimated MCV1 coverage increased worldwide from 72% to 84%. However, coverage stagnated at 84% to 86% during 2010–2019, decreased to 83% in 2020 during the COVID-19 pandemic, and further declined to 81% in 2021. Although regional variation exists, all six WHO regions reported a decline in MCV1 coverage since 2019, with only the European Region plateauing from 2020 to 2021 (Table 1).
Among 194 WHO member states, 91 (47%) achieved ≥90% MCV1 coverage in 2021; however, among these countries, only 24 (26%) reported MCV1 coverage of ≥80% in all districts. In 2021, 24.7 million infants did not receive MCV1 through routine immunization services, an increase of 2.4 million (11%) from 2020. The 10 countries with the highest number of infants who did not receive MCV1 were Nigeria (3.1 million), India (2.5 million), Democratic Republic of the Congo (1.7 million), Ethiopia (1.7 million), Indonesia (1.2 million), Pakistan (1.2 million), Philippines (1.0 million), Angola (0.8 million), Brazil (0.7 million), and Tanzania (0.5 million). These countries accounted for 59% of all children who did not receive MCV1. Estimated MCV2 coverage quadrupled from 17% in 2000 to 72% in 2020, then declined slightly, to 71% in 2021. The number of countries offering MCV2 increased by 92%, from 95 (50%) in 2000 to 182 (94%) in 2021. Three countries (Comoros, Côte d'Ivoire, and Equatorial Guinea) introduced MCV2 in 2021.††
Approximately 150 million persons received MCV during supplementary immunization activities (SIAs)§§ in 18 countries in 2021. An additional 4 million persons received MCV during measles outbreak response activities. As of December 2021, 25 MCV campaigns that had been postponed since the start of the COVID-19 pandemic had been conducted; however, 18 MCV campaigns planned since March 2020 had still not been conducted, which resulted in an estimated 61 million postponed or missed MCV doses.
Morbidity and Mortality Weekly Report. 2022;71(47):1489-1495. © 2022 Centers for Disease Control and Prevention (CDC)