The big catch-up in immunisation coverage after the COVID-19 pandemic: progress and challenges to achieving equitable recovery

Each year in mid-July WHO and UNICEF jointly release Estimates of National Immunization Coverage (WUENIC) for 195 member states. These estimates are the culmination of a comprehensive collection of essential health data, involving immunisation staff in every country, with data validated against large scale surveys and events such as vaccine stock-outs or other local service interruptions. The WUENIC 2021 estimates 1 WHOUNICEFWHO and UNICEF estimates of immunization coverage: 2021 revision, July 2022. World Health Organization, Geneva2022 Google Scholar showed the COVID-19 pandemic induced major disruptions to routine immunisation services that resulted in immunisation losses not seen for decades, which hampered polio eradication efforts and led to a resurgence of outbreaks of measles and yellow fever and increasing reports of diseases such as diphtheria and pertussis. 2 Shet A Carr K Danovaro-Holliday MC et al. Impact of the SARS-CoV-2 pandemic on routine immunisation services: evidence of disruption and recovery from 170 countries and territories. Lancet Global Health. 2022; 10: e186-e194 Summary Full Text Full Text PDF PubMed Google Scholar , 3 Causey K Fullman N Sorensen RJD et al. Estimating global and regional disruptions to routine childhood vaccine coverage during the COVID-19 pandemic in 2020: a modelling study. Lancet. 2021; 398: 522-534 Summary Full Text Full Text PDF PubMed Scopus (137) Google Scholar , 4 WHOYellow fever—African Region. https://www.who.int/emergencies/disease-outbreak-news/item/2022-DON431Date: Jan 3, 2023 Date accessed: July 11, 2023 Google Scholar , 5 Bigouette JP Henderson E Traoré MA et al. Update on vaccine-derived poliovirus outbreaks—worldwide, January 2021–December 2022. MMWR Morb Mortal Wkly Rep. 2023; 72: 366-371 Crossref PubMed Scopus (4) Google Scholar Reduced and delayed vaccination against human papillomavirus will incur future consequences with preventable cases of cervical cancer among women, mainly in low-income and middle-income countries where the burden is highest, and screening and treatment are weakest. 6 WHOHuman papillomavirus vaccines: WHO position paper, December 2022. Weekly Epidemiol Record. 2022; 50: 645-672 Google Scholar The Immunization Agenda 2030 (IA2030), ratified by all member states in 2020, committed to reduce by half the world's zero-dose children (ie, immunisation coverage), and promises to “leave no one behind” (ie, equity). 7 Immunization Agenda 2030Immunization Agenda 2030: a global strategy to leave no one behind. https://www.immunizationagenda2030.org/Date accessed: July 12, 2023 Google Scholar WHO and UNICEF, with partner Gavi, the Vaccine Alliance and IA2030 have designated 2023 as an intensified year of action termed “The Big Catch-Up”, calling for catching-up children who have missed immunisations, restoration of immunisation services to pre-pandemic levels, and strengthening these services to achieve IA2030 targets. 8 WHOGavithe Vaccine AllianceImmunization Agenda 2030UNICEFThe big catch-up: an essential recovery immunization plan for 2023 and beyond. World Health Organization, Geneva2023https://www.who.int/news/item/24-04-2023-global-partners-announce-a-new-effort-the-big-catch-up-to-vaccinate-millions-of-children-and-restore-immunization-progress-lost-during-the-pandemic?Date accessed: July 12, 2023 Google Scholar IA2030 calls for evidence-informed, target-driven, and experience-based accountability by immunisation partners and country programmes and for implementation to achieve quantitative commitments on immunisation coverage and equity made by every country. 9 WHO73rd World Health Assembly. Immunization Agenda 2030. World Health Organization, Geneva2021https://apps.who.int/gb/ebwha/pdf_files/WHA73/A73(9)-en.pdfDate accessed: July 11, 2023 Google Scholar