How do you save the lives of over 150 million children?
The answer: Childhood vaccinations.
Just over 50 years ago, the World Health Organization launched its Essential Programme on Immunization. Since then, vaccination rates have improved dramatically and researchers estimate that 4.4 billion people have been reached and 154 million childhood deaths have been avoided.
But don't celebrate too fast.
These long-term trends obscure a less rosy picture of what's happened in recent years, according to a study published on Tuesday in The Lancet. The researchers found that, since 2010, efforts to boost vaccination rates have stalled or reversed in many places.
For example, in 100 of the 204 countries researchers looked at, the percent of kids who got the measles vaccine dropped between 2010 and 2019. In Argentina, there was a 12% drop in kids getting their first dose of the measles vaccine.
Another example: Twenty-one of 36 high-income countries saw a decline in vaccination rates for at least one of the immunizations that WHO promoted back when it launched its immunization program — vaccines to prevent such diseases as diphtheria, tetanus, whooping cough, measles and polio. Take Finland, for instance. It saw an 8% drop in the children receiving the third dose of their diphtheria-tetanus-pertussis vaccination. In Austria, there was a 6% decline.
For the study, researchers pulled together more than 1,000 sources of data — everything from household surveys to national immunization reports — to piece together what is happening around the world.
"Underpinning the work is an immense data curation effort … providing strong foundations for the study's conclusions," said Edward Parker in a statement. He was not involved in the study and is the co-director of the Vaccine Centre at the London School of Hygiene & Tropical Medicine.
NPR spoke with Dr. Jonathan Mosser — one of the study authors and an assistant professor of health metrics sciences in the Institute for Health Metrics and Evaluation (IHME) at the University of Washington — to hear his thoughts about the findings.
Here are four points that stood out to Mosser.
This is "a critical time" when it comes to vaccines.
As Mosser and his colleagues pored over the data, he says, it was striking how much progress has been made and how many challenges the world faces.
"The past 50 years really illustrate the promise, the potential of vaccination," he says. "But, there are many challenges at the moment: There are challenges related to conflict, there are challenges related to supply chains and challenges associated with vaccine misinformation."
There are also big changes when it comes to funding for initiatives that get kids their vaccines, even if they are in low-income countries and in far-flung places. For example, the U.S. cut its billion dollar grant to Gavi, the Vaccine Alliance, which helps get vaccines for half the world's children. However, today, the Gates Foundation announced it will give $1.6 billion over the next five years to support Gavi.
Mosser says all the changes and challenges mean the world's vaccination efforts are "at a very critical time."
"The world is going to have to pick a trajectory," he says. "Are we going to turn our backs on one of the most remarkable public health achievements that the world has ever seen?"
India is "a big success" story: It's reduced the number zero-dose kids.
"Zero-dose children" are those who get no vaccines at all. That number is often measured as children who are missing their first dose of the diphtheria, tetanus, and pertussis vaccine.
The researchers estimate that the number of kids in India who got their first dose of the diphtheria, tetanus, and pertussis vaccine in 2023 was 93%, which is near levels in some high-income countries.
Mosser says India stands out as a country that has achieved very high vaccination rates across a very large population "and so that has been a big success story in the world of immunization."
He points to not only a universal immunization effort but also a highly targeted effort, where India set out to identify populations and locations where kids weren't getting vaccines, then designed programs to close the gaps. He also says, India has leaned into tech. One example: building a fancy system to monitor their vaccine supply chain and make sure the vaccines are where they need to be exactly when they are needed.
COVID was bad for vaccination rates — but it's getting better
The COVID pandemic was a major hurdle for vaccination efforts. Health care professionals were diverted from vaccination efforts, clinics closed, imports and exports of vials and syringes were scrambled. In 2021, over 25 million children missed at least one vaccination, according to the WHO.
There's been a concerted effort to find those kids and vaccinate them. Looking at the numbers, Mosser has been pleasantly surprised.
"One thing that stood out to us is that when we had initially looked at disruptions due to the COVID pandemic — during the first couple of months of the pandemic — we had expected even larger decreases in coverage than we saw," he says.
"We're not back to where we need to be, but…things could have been much worse," he adds, crediting local outreach efforts as well as large international initiatives such as The Big Catch-Up spearheaded by WHO, UNICEF, Gavi and the Bill & Melinda Gates Foundation (which is a sponsor of NPR and this blog).
The world's changing birth rate presents assurances – and challenges.
The number of children born each year is expected to shrink by about 1.6% between now and 2030. But not every country is part of this trend — and that matters for vaccination efforts, says Mosser.
"In many countries where vaccine coverage is low, there has been — and continues to be — a large increase in the [population]," Mosser says. "And so when more children are born each year, it simply requires more resources to achieve the same levels of vaccination coverage."
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