Estimating global changes in routine childhood vaccination coverage during the COVID-19 pandemic, 2020-2021

Objectives: The COVID-19 pandemic has disrupted the distribution of routine immunizations globally. Multi-country studies assessing a wide spectrum of vaccines and their coverage rates are needed to determine global performance in achieving vaccination goals. Methods: Global vaccine coverage data for 16 antigens were obtained from WHO/UNICEF Estimates of National Immunization Coverage. Tobit regression was performed for all country-antigen pairs for which data were continuously available between 2015-2020 or 2015-2021 to predict vaccine coverage in 2020/2021. Vaccines for which multi-dose data were available were assessed to determine whether vac-cine coverage for subsequent doses were lower than that of first doses. Results: Vaccine coverage was significantly lower-than-predicted for 13/16 antigens in 2020 and all assessed antigens in 2021. Lower-than-predicted vaccine coverage was typically observed in South America, Africa, Eastern Europe, and Southeast Asia. There was a statistically significant coverage drop for subsequent doses of the diphtheria-tetanus-pertussis, pneumococcus, and rotavirus vaccines com-pared to first doses in 2020 and 2021. Conclusion: The COVID-19 pandemic exerted larger disruptions to routine vaccination services in 2021 than in 2020. Global efforts will be needed to recoup vaccine coverage losses sustained during the pan-demic and broaden vaccine access in areas where coverage was previously inadequate. & COPY; 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).