Sharp drop in childhood vaccinations threatens millions of lives

It is the largest backslide in routine immunization in 30 years, according to a new analysis from UNICEF, the United Nations agency that vaccinates half the world's children, and the World Health Organisation

By Stephanie Nolen

Published: Jul 15, 2022

Child seen receiving dose of polio vaccine at health posts in Eunapolis (BA). Image: Shutterstock

Millions of children around the world, most of them in the poorest countries, missed some or all of their childhood vaccinations over the past two years because of a combination of conflicts, climate emergencies, misinformation campaigns, pandemic lockdowns and COVID-19 vaccination efforts that diverted resources, according to a new analysis from UNICEF, the United Nations agency that vaccinates half the world’s children, and the World Health Organization.

It is the largest backslide in routine immunization in 30 years, the report said. Combined with rapidly rising rates of malnutrition, it has created conditions that could threaten the lives of millions of young children.

“This is an emergency for children’s health — we have to think about the immediate stakes, the number of children that are going to die because of this,” said Lily Caprani, head of advocacy for UNICEF. “It’s not in a few years’ time; it’s quite soon.”

The percentage of children worldwide who had received three doses of the vaccine against diphtheria, tetanus and pertussis, known as DTP3 — which UNICEF uses as a benchmark for immunization coverage — fell 5 points between 2019 and 2021, to 81%. Measles vaccination rates also fell to 81%, and polio coverage dropped significantly, too. A vaccination coverage rate of 94% is necessary for herd immunity, to interrupt the chain of transmission of a disease.

This translates to 25 million children who did not receive a basic intervention to protect against lethal illnesses.

The number of what UNICEF calls zero-dose children — those who have not received a single dose of the most basic vaccines — increased sharply during the pandemic, to 18 million from 13 million in 2019. This group includes half of all children who die before age 5.

The agency had been hoping that after a sharp decline in 2020 that was driven by lockdowns, school closures and other COVID-19 response measures, childhood vaccination coverage would rebound in 2021, said Dr. Niklas Danielsson, UNICEF’s Nairobi-based senior immunization specialist.

But instead, the problem got worse. DTP3 and measles coverage are at the lowest level since 2008, the report found.

Danielsson said the rate of vaccination coverage in 2021 matched that of 2008. “But since then, the birth cohorts have increased, which means that the number of children who do not complete vaccinations, or do not even start, is the largest in the last 30 years,” he said.

He and many others in the child-immunization field had anticipated a recovery last year as health systems learned to adapt to the demands of the pandemic. Instead, misinformation campaigns about COVID-19 vaccination, and broader mistrust of governments over public health measures, spilled over to deter routine immunization, he said.

At the same time, health systems in the poorest countries scrambled to carry out limited COVID-19 vaccination, diverting critical access to freezers and the health workers to put shots in arms.

Over the past two years, India, Nigeria, Indonesia, Ethiopia and the Philippines recorded the highest numbers of children who had missed out on vaccines.

Brazil was also on the list of the 10 most-affected countries, a harsh shift for a country once renowned for its high vaccination coverage rates. About 26% of Brazilian infants had received no vaccines in 2021, compared with 13% in 2018.

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“The work of 30 years has been lost overnight,” said Dr. Carla Domingues, a public health researcher and former coordinator of Brazil’s national immunization program.

Vaccination became a politicized subject in Brazil during the COVID-19 pandemic, she said. The federal government, led by President Jair Bolsonaro, downplayed the significance of the coronavirus even as Brazil had one of the world’s highest death rates and said he would not get his own 11-year-old vaccinated against the virus.

“For the first time, the federal government was not recommending a vaccine, and it created a whole environment of doubt that had never existed in Brazil, where vaccination was totally accepted,” Domingues said.

At the same time, anti-vaccination groups that had not had much purchase in Brazil moved into the country during the pandemic, she said, and began circulating misinformation in Portuguese on social media.

And all of this was happening, Domingues said, at a time when Brazilians were a generation removed from the serious illnesses they were being urged to vaccinate their children against, leading them to question the necessity.

“Parents don’t know the impact of measles, or of polio, so they start to pick and choose vaccinations,” she said. Data showing that acceptance of the pneumonia vaccine is higher than that for polio makes that clear. “Parents are choosing not to do polio. They say, ‘It’s been 30 years with no polio, so do I need to do this?’”

And yet they have a clear sign of the risk, she said: A handful of measles cases were found earlier this year in Sao Paulo, six years after Brazil had reported eradicating the disease. “Measles is now circulating — that gives us a concrete example of what could happen with diphtheria, meningitis and so many other diseases,” she said.

Dr. Fabien Diomande, a polio eradication expert with the Task Force for Global Health who worked for years on polio campaigns in West and Central Africa, said reversing the decline in childhood immunization would require new nimbleness, innovation and resources.

Caprani said that although there was a heartening renewed interest in global health cooperation because of COVID-19, investment in new surveillance measures and other novelties risked distracting from the simple intervention needed to address the child immunization crisis: deployment of thousands of community health workers.

“We aren’t going to solve this with poster campaigns or social media posts,” she said. “You need outreach by reliable, well-trained, properly compensated community health workers who are out there day in, day out, building trust — the kind of trust that means you listen to them about vaccines. And there simply aren’t enough of them.”