Progress Toward Regional Measles Elimination — Worldwide, 2000–2021

Anna A. Minta, MD; Matt Ferrari, PhD; Sebastien Antoni, MPH; Allison Portnoy, ScD; Alyssa Sbarra, MPH; Brian Lambert; Sarah Hauryski; Cynthia Hatcher, MPH; Yoann Nedelec, MPH; Deblina Datta, MD; Lee Lee Ho, MPH; Claudia Steulet, MPH; Marta Gacic-Dobo, MSc; Paul A. Rota, PhD; Mick N. Mulders, PhD; Anindya S. Bose, MD; William A. Perea; Patrick O'Connor, MD


Morbidity and Mortality Weekly Report. 2022;71(47):1489-1495. 

In This Article

Measles Case and Mortality Estimates

A previously described model[3] for estimating measles cases and deaths was updated with 2021 measles data and United Nations 2000–2021 population estimates.§§§ Data on case fatality from an updated systematic review and a suite of covariates with known relationships to case fatality were used in a Bayesian meta-regression modeling framework to produce estimates of measles case fatality ratios¶¶¶.[4] The updated estimates reflect heterogeneity among countries, years, and ages. On the basis of the revised model and 2021 data, the estimated number of measles cases decreased 72%, from 34,013,000 in 2000 to 9,484,000 in 2021; estimated annual measles deaths decreased 83%, from 761,000 to 128,000 (Table 2). However, the estimated numbers of both cases and deaths were higher in 2021 compared with those in 2020. During 2000–2021, compared with no measles vaccination, measles vaccination prevented an estimated 56 million deaths globally (Figure).


Estimated number of annual measles deaths with measles vaccination and in the absence of measles vaccination — worldwide, 2000–2021*
*Deaths prevented by vaccination are estimated by the area between estimated deaths with vaccination and those without vaccination (cumulative total of 56 million deaths prevented during 2000–2021). Vertical bars represent 95% CIs around the point estimate.

§§§State-space model of unobserved measles incidence during 2000–2021 generated using the following inputs from all member countries: 1) total annual reported measles cases, 2) annual MCV1 coverage from WHO-UNICEF estimates of national immunization coverage, 3) annual MCV2 coverage from WHO-UNICEF estimates of national immunization coverage, 4) annual SIAs with coverage and age targets (subnational SIAs are discounted by the proportion of the total population targeted), 5) annual total population size, 6) total annual births, and 7) list of all countries and years for which reporting was enhanced.
¶¶¶The model fitted the reported case fatality ratios from the systematic review as a function of the following covariates: 1) gross domestic product per capita, 2) HIV prevalence, 3) maternal education, 4) MCV1 coverage, 5) proportion urban, 6) total fertility rate, 7) mortality rate among children aged <5 years, 8) vitamin A deficiency prevalence, 9) war and terrorism mortality rate, 10) wasting prevalence, and 11) measles incidence. Annual measles incidence for each country was based on this fitted state-space model. High income countries were excluded from this analysis.