BarcelonaThe COVID-19 pandemic has accelerated the development and distribution of coronavirus vaccines with unprecedented speed, but it has also been marked by a significant decline in the rate of systematic vaccinations, i.e. those included in children’s calendars. According to data published by the World Health Organization and UNICEF on Monday, global childhood immunization coverage will stagnate in 2023, meaning that this year there will be 2.7 million more children unvaccinated or not receiving all required vaccines compared to pre-pandemic levels in 2019. “The latest trends show that in many countries there are far too many children unvaccinated,” UNICEF Executive Director Catherine Russell said in presenting the report. “Closing the immunization gap will require a global effort,” she added.
The World Immunization Coverage Index (Wuenic) is the world’s largest dataset on vaccination trends against 14 diseases. As detailed in the report, the number of children receiving the three doses of diphtheria, tetanus and pertussis (DTP3) in 2023 – a key marker of global immunization coverage – remained stable at 84%, representing 108 million children. This is the same figure as in 2022, but down from 86% in 2019.
“One of the problems that has been observed is the significant impact that the coronavirus has had on maintaining vaccination levels against other pathogens, and in some cases, this has led to a decrease in vaccination coverage, with children who have not received any dose or the full schedule of some vaccines,” explains CINEBIO researcher and professor of immunology at the University of Vigo in Africa González, in statements to the Scientific Information Center (SMC). “The pandemic has led to health resources being allocated mainly to Covid. Many campaigns have been suspended in countries with scarce resources, and epidemiological surveillance has decreased,” explains Ferran Moraga, pediatrician and spokesperson for the Spanish Association of ARA of Vaccinology (AEV).
Similarly, the data also shows that the number of children who did not receive a dose of DTP3 vaccine increased from 13.9 million in 2022 to 14.5 million in 2023. Overall, the data represents a decline from the goals set by the Immunization Agenda 2030, which calls for achieving 90% coverage with basic vaccines for children and adolescents and reducing the number of children receiving “zero doses” to fewer than 6.5 million children worldwide by 2030.
Alert for the resurgence of measles
The data also show that vaccination rates against measles, a potentially deadly disease, have stagnated, leaving nearly 35 million children unprotected or only partially protected. Last year, only 83% of boys and girls worldwide received the first dose of the measles vaccine, while the number of children receiving the second dose increased slightly year-on-year, to 74%. In Catalonia, the rates rise to 94.5% for the first dose and 91.8% for the second dose. “The most striking thing about this vaccination stagnation is measles coverage,” Moraga-Lupe emphasizes. “After the epidemic, in the world, in Europe, in Spain, measles has resurfaced, and this has happened in very different countries. “Depending on the vaccination coverage of the countries,” he adds.
According to data from the Ministry of Health, 106 cases of measles were reported in Spain between January and June 11, 2024. Last year, only 14 cases were confirmed. “There is a difference. It should not cause alarm, but it should be a cause for caution and concern. We have not reached basic coverage,” insists the AEV spokesperson. “If at any moment there is a major resurgence in Europe and neighbouring countries, there will be groups of vulnerable people,” he continues. For WHO Director-General Tedros Adhanom Ghebreyesus, this problem has a solution. “The measles vaccine is cheap and can be administered even in the most difficult places,” he adds. However, in the past five years, measles outbreaks have affected 103 countries, where almost three-quarters of the world’s infants live, and where low vaccination coverage (80%) has had a major impact.
Less coverage in fragile countries
The data also show that more than half of unvaccinated children live in 31 countries with “fragile, conflict-affected and vulnerable contexts,” where they are particularly vulnerable to disease. “New active conflicts in certain areas of Europe and the Eastern Mediterranean are expected to worsen the conditions for their populations to access health services and immunizations. The situation of the populations of Gaza and other areas of the region is particularly dire,” warns the UN. Pediatrician and collaborator on the Vaccine Advisory Committee of the Spanish Pediatric Society, Angel Hernández Merino, told SMC.
But even in Spain, there are differences between autonomous communities, cities and neighbourhoods, Moraga-Lupe points out, adding: “Campaigns and strategies to promote vaccination in specific places need to be implemented.” On the other hand, the report also showed that 6.5 million children have not received the third dose of pertussis vaccine, which is necessary to provide protection against the disease during infancy and in the first years of life.
Increased coverage against HPV
The report also highlights more encouraging data: the continued introduction of new and underused vaccines, including HPV, meningitis, pneumococcal, polio and rotavirus, is expanding protection. For example, the proportion of adolescent girls worldwide who have received at least one dose of the HPV vaccine—which protects against cervical cancer—has risen from 20% in 2022 to 27% in 2023, returning to near pre-pandemic levels. However, HPV vaccine coverage is far below the 90% target, reaching just 56% of adolescent girls in high-income countries and 23% in low-income countries.
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