New data published on Monday by UN agencies shows that immunization coverage for children worldwide stalled during 2023, leaving around 2.7 million lacking the protection they need compared to the pre-COVID-19 levels of 2019.

That’s according to the World Health Organization (WHO) and UN Children’s Fund (UNICEF) snapshot of trends for vaccinations against 14 diseases – all of which underlines the need for ongoing catch-up, recovery and system-strengthening efforts.

“The latest trends demonstrate that many countries continue to miss far too many children,” said UNICEF Executive Director Catherine Russell. “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.”

The number of children who received three doses of the vaccine against diphtheria, tetanus and pertussis (DTP) in 2023 - a key marker for global immunization coverage - stalled at 84 per cent (108 million).

Going backwards

However, those 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 unvaccinated children live in 31 countries with fragile, conflict-affected and vulnerable settings, where children are especially vulnerable to preventable diseases because of disruptions and lack of access to security, nutrition, and health services, the agencies reported.

Additionally, 6.5 million children did not complete their third dose of the DTP vaccine, which is necessary to achieve disease protection in infancy and early childhood.

These trends, which show that global immunization coverage has remained largely unchanged since 2022 and – more alarmingly - has still not returned to 2019 levels, reflect ongoing challenges with disruptions in services, logistical challenges, vaccine hesitancy and inequities in accessing shots.

Emerging measles outbreaks

The data further show that vaccination rates against the deadly measles disease stalled, leaving nearly 35 million children lacking sufficient protection.

In 2023, only 83 per cent of children worldwide received their first dose of the measles vaccine through routine health services, while the number of children receiving their second dose modestly increased from the previous year, reaching 74% of children.

These figures fall short of the 95 per cent coverage needed to prevent outbreaks, avert unnecessary disease and deaths, and achieve measles elimination goals.

Over the last five years, measles outbreaks hit 103 countries – home to roughly three-quarters of the world’s infants. Low vaccine coverage (80% or less) was a major factor. In contrast, 91 countries with strong measles vaccine coverage did not experience outbreaks.

Canary in the mine

“Measles outbreaks are the canary in the coalmine, exposing and exploiting gaps in immunization and hitting the most vulnerable first,” said Dr Tedros Adhanom Ghebreyesus, WHO Director-General.

“This is a solvable problem. Measles vaccine is cheap and can be delivered even in the most difficult places. WHO is committed to working with all our partners to support countries to close these gaps and protect the most at-risk children as quickly as possible.”

Good news on Global HPV vaccine coverage

The new data also highlight some brighter spots in immunization coverage.

The steady introduction of some newer vaccines, including  for human papillomavirus (HPV), meningitis, pneumococcal, polio and rotavirus disease, continues to expand protection - particularly in the 57 countries supported by Gavi, the Vaccine Alliance. 

For example, the share of adolescent girls globally who received at least one dose of the HPV vaccine, which provides protection against cervical cancer, increased from 20% in 2022 to 27% in 2023.

"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,” said Dr Sania Nishtar, CEO of Gavi.

However, HPV vaccine coverage is well below the 90 per cent target to eliminate cervical cancer as a public health problem, reaching only 56 per cent of adolescent girls in high-income countries and 23% in low and middle-income countries.