鈥淎fter clean water, vaccination is the most effective intervention for protecting the health of our children,鈥� said Helen Bedford, a professor of children's health at University College London, who was not connected to the research. She warned there has been a small but worrying rise in the number of parents skipping vaccination for their children in recent years, for reasons including misinformation.

In Britain, Bedford said that has resulted in the largest number of measles recorded since the 1990s and the deaths of nearly a dozen babies from whooping cough. Vaccination rates in the U.S. are also falling, and are at an all-time high.

After the World Health Organization established its routine immunization program in 1974, countries made significant efforts to protect children against preventable and sometimes fatal diseases; the program is credited with inoculating more than 4 billion children, saving the lives of 154 million worldwide.

Since the program began, the global coverage of children receiving three doses of the diphtheria-tetanus-whooping cough vaccine nearly doubled, from 40% to 81%. The percentage of kids getting the measles vaccine also jumped from 37% to 83%, with similar increases for polio and tuberculosis.

But after the COVID-19 pandemic, coverage rates dropped, with an estimated 15.6 million children missing out on the diphtheria-tetanus-whooping cough vaccine and the measles vaccine. Nearly 16 million children failed to get vaccinated against polio and 9 million missed out on the TB vaccine, with the biggest impact in sub-Saharan Africa. The study was funded by the Bill & Melinda Gates Foundation and Gavi, The Vaccine Alliance.

Ina pledge of support for Gavi, the British government announced Wednesday it will give 1.25 billion pounds ($1.7 billion) between 2026 and 2030 to the international vaccine alliance. It said the money will help Gavi protect up to 500 million children in some of the world鈥檚 poorest countries from diseases including meningitis, cholera and measles, potentially saving 8 million lives.

Health advocates welcomed the money but some noted it is less than the 1.65 billion pounds the U.K. pledged over the five years from 2020.

Researchers at the Institute for Health Metrics and Evaluation at the University of Washington, who conducted the Lancet analysis, noted that more than half of the world鈥檚 15.7 million unvaccinated children live in just eight countries in 2023: Nigeria, India, Congo, Ethiopia, Somalia, Sudan, Indonesia and Brazil.

Since President Trump has begun to and dismantled the , public health experts have warned of new epidemics of infectious diseases. The researchers said it was too early to know what impact recent funding cuts might have on children's immunization rates.

The WHO said there had been an 11-fold spike in measles in the Americas this year compared to 2024. Measles infections doubled in the European region in 2024 versus the previous year and the disease remains common in Africa and Southeast Asia.

鈥淚t is in everyone's interest that this situation is rectified,鈥� said Dr. David Elliman, a pediatrician who has advised the British government, in a statement. 鈥淲hile vaccine-preventable infectious diseases occur anywhere in the world, we are all at risk.鈥�

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