Routine vaccines have prevented the deaths of about 154 million children around the world over the past 50 years, a new study shows, but efforts have been slowing recently, allowing for the growth of some vaccine-preventable diseases. This backslide could lead to many more unnecessary illnesses and deaths without an increased effort to vaccinate children and counter misinformation.
The report, published Tuesday in the medical journal The Lancet, says that over the past five decades, the World Health Organization’s Expanded Programme on Immunization has vaccinated more than 4 billion children. This doubling of global coverage of vaccines has prevented countless cases of tuberculosis, measles, polio, diphtheria, tetanus and pertussis.
There was a concerted effort to vaccinate people between 1980 and 2023, the researchers found, resulting in a 75% drop in the number of children who are “zero-dose” — those younger than 1 who have not received any doses of the diphtheria-tetanus-pertussis vaccine, which is often used as a way to measure overall immunization coverage.
“Childhood immunization has proven to be one of the most successful and cost-effective public health strategies known both in terms of lives saved and return on investment,” the researchers wrote. The financial rate of return is, in some instances, up to 44 times the cost of vaccination, they say.
But despite this success, the study says, vaccination efforts have been slowing, and in some cases, progress has even been reversed.
Between 2010 and 2019, there were declines in at least one kind of vaccination in 21 of 36 high-income countries measured in the research.
Gavi, The Vaccine Alliance, an international effort that helps vaccinate children in developing countries and helped fund the new research, says that essential childhood immunizations declined in more than 100 countries around the world between 2010 and 2019, leading to outbreaks of vaccine-preventable diseases like polio, diphtheria and yellow fever. Bill & Melinda Gates Foundation also helped fund the research.
The Covid-19 pandemic also slowed vaccination efforts significantly as more people stayed home and avoided medical visits. The number of zero-dose children globally peaked at 18.6 million in 2021 during the pandemic before falling to 15.7 million in 2023.
The pandemic isn’t the only phenomenon to blame for falling vaccination rates. Violent conflicts, political volatility, climate-related crises, the intensification of migration and displacement of populations, and vaccine misinformation have also posed obstacles to vaccination.
Misinformation about vaccines has grown so prevalent that WHO identified it in 2019 as one of the leading threats to global health.
Vaccination efforts in the US and other regions may slow even further with new leadership. President Donald Trump’s proposed 2026 budget defunds multiple crucial vaccine campaigns overseas.
The proposal would shut down the US Centers for Disease Control and Prevention’s global health unit, which would end its massive program that vaccinates children against polio, measles and other diseases. The proposal would also zero out US funding for Gavi.
Trump also chose vaccine skeptic Robert F. Kennedy Jr. to lead HHS. Despite pledging during his confirmation hearings that he would not infringe on Americans’ access to vaccines, Kennedy said in May that the Covid-19 shot would no longer be recommended for healthy children and pregnant women. Amid an ongoing multistate measles outbreak, he focused on unconventional treatments instead of vaccination, and this month, Kennedy fired the members of the US Centers for Disease Control and Prevention’s vaccine advisory committee and replaced them with new members, many of whom have questioned vaccine safety or been accused of spreading misinformation.
Kennedy said in a videos shown at a Gavi fundraising event in Brussels on Wednesday, and seen by Reuters that the US government wouldn’t send funds to Gavi until it considers the “best science available” concerning what he characterized, without providing evidence, as safety concerns about vaccines. In response to Kennedy’s remarks, Gavi said its “utmost concern is the health and safety of children.”
In the United States, surveys show that most parents still think childhood vaccines are important and keep their kids up-to-date, but kindergarten vaccine exemption rates in the 2023-24 school year were the highest ever reported, research showed. Rates in some jurisdictions exceeded 5%, CDC research found.
The US is nearing a record for most measles cases reported in a single year since the disease was declared eliminated in 2000, largely because of outbreaks among unvaccinated people. There was also a nearly 10-fold increase in measles infections recorded in the EU and the European Union economic area alone in 2024, the study said.
“Despite the monumental efforts of the past 50 years, progress has been far from universal. Large numbers of children remain under- and un-vaccinated,” said senior study author Dr. Jonathan Mosser of the Institute for Health Metrics and Evaluation at the University of Washington.
The majority of children who have never gotten a vaccine are outside the US, the study says. They’re concentrated in eight countries: Nigeria, India, the Democratic Republic of Congo, Ethiopia, Somalia, Sudan, Indonesia and Brazil.
Because the reasons for a lack of vaccination vary by country, the researchers argue that public health experts will need to create targeted campaigns to get more people vaccinated, especially if WHO wants to achieve its target of 90% global vaccine coverage by 2030.
“Sustained investment and targeted strategies will be essential to maintain progress, close immunisation gaps, and ensure equitable access to life-saving vaccines,” wrote Hai Fang, a professor who specializes in vaccine economics and epidemiology of infectious disease at the Peking University Health Science Center and the Chinese Center for Disease Control and Prevention’s Joint Center for Vaccine Economics, in an editorial that accompanied the study in the Lancet.