The World Health Organization credits immunization with stopping somewhere between 3.5 million and 5 million deaths each year from illnesses such as diphtheria, tetanus, whooping cough, influenza and measles. The same pages carry a warning, though: too many children are still being missed.
Start with the headline coverage number. WHO’s tally for 2025 has 110 million infants, about 85% of the world’s total, getting all 3 doses of the diphtheria-tetanus-pertussis vaccine, known as DTP3. That sounds solid until the remainder is counted. Some 13.5 million infants got no first dose at all, and another 6 million were only partly vaccinated. About 53% of the nearly 20 million children who are unvaccinated or under-vaccinated live in just 10 countries. WHO names Afghanistan, Angola, Ethiopia, India, Indonesia and the Philippines among them, plus Congo (the DRC).
UNICEF’s count is a little higher. More than 14 million infants received not a single vaccine last year, it reports, and the poorest and most marginalized children are the least likely to be reached. The agency lists conflict, displacement, COVID-19 disruption, economic crisis and misinformation among the causes.
Measles shows the gap first
Measles spreads so easily that it exposes holes in immunity before anything else does. WHO says the share of children getting a first dose was 84% in 2025, below the 86% recorded in 2019. Nearly 21 million children missed that routine first dose in 2025, against 19 million in 2019. About 29 million infants remained under-protected.
The longer record is still a strong one. Estimated measles deaths dropped from 780 000 in 2000 down to 95 000 by 2024, and WHO credits it with averting nearly 59 million deaths over those years. Before the vaccine arrived in 1963, big epidemics hit about every second or third year and killed an estimated 2.6 million people annually. In 2024 most of the dead were unvaccinated or under-vaccinated children under 5.
UNICEF estimates vaccines have saved 154 million lives over the past 50 years. It also says each US$1 spent on vaccination returns US$54 in wider economic benefit, and that its own work reaches close to half the children on the planet each year.
Sources
- Immunization coverage fact sheet (WHO)
- Vaccines and immunization (WHO)
- Measles fact sheet (WHO)
- Immunization (UNICEF)
