Huge numbers of children missed out on crucial immunisation campaigns for diseases such as diphtheria, tetanus and pertussis last year as a surge in conflict around the world disrupted supplies of life-saving vaccines, mostly in conflict-hit areas, the United Nations said on Monday.

According to UN estimates, about 14.5 million children missed vaccinations in 2023, compared to 13.9 million a year earlier. However, this number was lower than during the COVID-19 pandemic, when about 18 million children missed vaccinations.

The UN also said an additional 6.5 million children did not receive more than one dose, meaning they were not fully protected.

This estimate is based on how many children received the first dose or all three doses of the DTP vaccine. DTP is a core vaccine that protects against diphtheria, tetanus, and pertussis (also called whooping cough).

Overall, 84% of infants worldwide received the full dose last year, far below the level needed to prevent disease outbreaks.

The United Nations Children’s Fund (UNICEF) and the World Health Organization (WHO) said in a press conference last week ahead of releasing the figures that a large increase was expected in the number of children not vaccinated in 2023, particularly in war-affected countries.

The biggest drop in vaccination coverage globally occurred in Sudan, which has been ravaged by a 15-month civil war. The coverage rate here fell from 75% in 2022 to 57% in 2023.

This means that around 701,000 children in Sudan have not been vaccinated against life-threatening diseases such as measles and diphtheria.

The number of children who could not be vaccinated in the occupied Palestinian territories during the nine months of last year rose to 17,000, from 1,000 in 2021, based on data available till September, the agencies said.

Sudan, Yemen and Afghanistan are new entrants to the list of 20 countries with the most unvaccinated or “zero dose” children in 2023.

UNICEF said more than half of the world’s unvaccinated children live in fragile, conflict-affected or insecure countries, although these countries make up only 28% of the global birth cohort.

There were some positives in the UN report. For example, the number of children with “zero doses” in the African region decreased by about 600,000 in 2023 compared to 2022, and coverage of the HPV vaccine, which prevents cervical cancer, also improved globally.

Ukraine also saw improvements, despite its war with Russia.