Recent data published by the World Health Organization (WHO) and UNICEF reveals that global childhood immunization coverage stalled in 2023, leaving 2.7 million additional children un- and under-vaccinated compared to pre-pandemic levels in 2019. This stagnation has significant implications for public health, particularly in the context of preventable diseases like measles, diphtheria, tetanus, and pertussis.
The latest WHO and UNICEF estimates of national immunization coverage (WUENIC) provide the most comprehensive dataset on immunization trends for vaccines against 14 diseases. These estimates highlight the urgent need for ongoing catch-up, recovery, and system-strengthening efforts to close the immunization gap. UNICEF Executive Director Catherine Russell emphasized the importance of a global effort, stating, “Closing the immunization gap requires a global effort, with governments, partners, and local leaders investing in primary healthcare and community workers to ensure every child gets vaccinated, and that overall healthcare is strengthened.”
In 2023, the number of children who received three doses of the vaccine against diphtheria, tetanus, and pertussis (DTP) – a key marker for global immunization coverage – remained at 84% (108 million). However, the number of children who did not receive a single dose of the vaccine increased from 13.9 million in 2022 to 14.5 million in 2023. More than half of these unvaccinated children live in 31 countries with fragile, conflict-affected, and vulnerable settings. These environments pose significant challenges due to disruptions in health services, logistical barriers, vaccine hesitancy, and inequities in access to services.
Moreover, 6.5 million children did not complete their third dose of the DTP vaccine, which is necessary for full protection during infancy and early childhood. These trends indicate that global immunization coverage has remained largely unchanged since 2022 and, alarmingly, has not returned to 2019 levels. This stagnation is reflective of ongoing healthcare service disruptions and the need for enhanced efforts to ensure vaccine access and acceptance.
Low vaccine coverage is already driving measles outbreaks. The data show that vaccination rates against the deadly measles disease stalled, leaving nearly 35 million children with no or only partial protection. In 2023, only 83% of children worldwide received their first dose of the measles vaccine through routine health services. The number of children receiving their second dose increased slightly, reaching 74%, but these figures fall short of the 95% coverage needed to prevent outbreaks and achieve measles elimination goals.
Over the past five years, measles outbreaks have hit 103 countries, affecting roughly three-quarters of the world’s infants. In contrast, 91 countries with strong measles vaccine coverage did not experience outbreaks. WHO Director-General Dr. Tedros Adhanom Ghebreyesus pointed out, “Measles outbreaks are the canary in the coal mine, exposing and exploiting gaps in immunization and hitting the most vulnerable first.” He emphasized the solvable nature of this problem, noting that the measles vaccine is inexpensive and can be delivered even in challenging environments. WHO is committed to working with partners to support countries in closing these gaps and protecting the most at-risk children.
On a more positive note, the new data highlight some brighter spots in immunization coverage. The steady introduction of new and under-utilized vaccines, including those for human papillomavirus (HPV), meningitis, pneumococcal, polio, and rotavirus diseases, continues to expand protection. For example, the share of adolescent girls globally who received at least one dose of the HPV vaccine increased from 20% in 2022 to 27% in 2023. This increase was largely driven by strong introductions in Gavi-supported countries like Bangladesh, Indonesia, and Nigeria. The use of the single-dose HPV vaccine schedule also helped boost coverage.
Dr. Sania Nishtar, CEO of Gavi, the Vaccine Alliance, remarked, “The HPV vaccine is one of the most impactful vaccines in Gavi’s portfolio, and it is incredibly heartening that it is now reaching more girls than ever before.” However, HPV vaccine coverage is still below the 90% target to eliminate cervical cancer as a public health problem, reaching only 56% of adolescent girls in high-income countries and 23% in low- and middle-income countries.
A recent poll of over 400,000 users of UNICEF’s digital platform for young people, U-Report, revealed that over 75% are unaware or unsure of what HPV is. When informed about the virus, its link to cancers, and the existence of a vaccine, 52% of respondents indicated they wanted to receive the HPV vaccine but were hindered by financial constraints and lack of availability.
To achieve the Immunization Agenda 2030 (IA2030) targets of 90% coverage and no more than 6.5 million ‘zero-dose’ children globally by 2030, robust local action is needed. This includes increased investment in innovation, collaboration, and support for country leadership to improve routine immunization as part of integrated primary healthcare programs. Such efforts must be backed by political support, community leadership, and sustainable funding.
In summary, the global childhood immunization landscape in 2023 highlights significant challenges and areas for improvement. While there are bright spots, particularly with new vaccines like HPV, substantial efforts are needed to close the immunization gaps and protect all children from preventable diseases.
