Change in Measles Vaccine Coverage and Estimated Impact on Measles Mortality in Low and Middle Income Countries, 2020: An Investigation into Secondary Public Health Effects of the COVID-19 Pandemic Using the Lives Saved Tool

With the global COVID-19 pandemic, many public health services were severely disrupted. Estimating the overall health effects of this is difficult as most disease surveillance systems have also been substantially affected during the pandemic. For some diseases, this effect is mitigated by the methods enacted to fight the pandemic, such as use of facial coverings, social distancing and quarantine, but measles is infectious to the degree that this mitigation is likely to be limited. Thus, outbreaks and an increase in global measles mortality are expected. However, the severity of this impact is not yet known. In early 2020, a study by Roberton and colleagues predicted an additional 12,360 to 37,920 deaths in children under-five worldwide from measles over the coming year based on three potential levels of vaccine coverage reductions ranging from 18.5 to 51.9%. Our study investigates the magnitude of the increase in measles mortality due to decreased vaccine coverage because of COVID-19, based on official estimates of 2020 measles vaccine coverage from WHO/UNICEF released in July 2021. Using the Lives Saved Tool (LiST), an interventions modeling program, we estimated measles mortality for low/middle income countries (LMICs) based on the 2020 WHO/UNICEF estimates of national immunization coverage (WUENIC). Because these calculations use actual reported vaccine coverage, they provide a more accurate picture of measles mortality related to COVID-19 disruptions in 2020. Using the WUENIC data, LiST predicted fewer additional deaths in 2020 due to decreases in measles vaccine coverage than estimations made by LiST based on Roberton, 2020 due to remarkable recovery efforts by national immunization programmes in the second half of 2020.