[This document forms part of a series of discussion notes notes addressing fundamental questions about global health. Its purpose is to transfer scientific knowledge into the public conversation and the decision-making process. These documents are based on the best information available and may be updated as new information comes to light.]
The COVID-19 pandemic has affected immunization programmes around the world, putting years of extraordinary achievements at risk. Millions of children missed out on essential vaccinations and could now contract preventable diseases due to disruptions in services and supply chains, diversion of resources to the COVID-19 response, and containment measures that limited access to and availability of vaccination services.
Official data published on 15 July by the World Health Organization (WHO) and UNICEF show the largest continued backslide in vaccinations in three decades. Last year alone, 25 million children missed out on one or more doses of DPT (diphtheria, tetanus and pertussis) vaccine as part of routine immunisation services, two million more than in 2020 and six million more than in 2019. Of these 25 million children, 18 million did not receive a single dose of DPT vaccine during the year.
Before the COVID-19 pandemic, vaccination coverage was already falling at an alarming rate worldwide, mainly due to vaccine hesitancy and resource constraints. So much so that measles mortality had peaked in 2019, with more than 200,000 deaths. The COVID-19 pandemic has contributed to worsening this decline.
This historic setback in vaccination rates is already having consequences. The world is re-experiencing a rapid resurgence of measles. In April 2022, WHO reported 21 major outbreaks during 2021, mostly in Africa and the Eastern Mediterranean. A similar phenomenon is observed for other vaccine-preventable diseases. Yellow fever has reappeared in Africa, for example, and countries such as Kenya are reporting cases after 25 years without a single case. On the other hand, Africa had been declared free of natural polio in August 2020, after a four-year period with no reported cases, but it has already re-emerged in Malawi and Mozambique.
The COVID-19 pandemic thus leaves a tragic immunisation gap, especially in low- and middle-income countries. Urgent action is needed to reverse it.
This paper, written by Isabelle Munyangaju (ISGlobal), and part of a series dedicated to the impact of COVID-19 on other pandemics, addresses not only the disruptions caused by the pandemic but also the systemic challenges of vaccination.