New Delhi: A new global study published in The Lancet has revealed a concerning decline in childhood vaccination coverage in many countries since 2010, putting millions of children at increased risk of preventable diseases and deaths. The study was led by researchers from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington.
The research analysed data from 204 countries and territories, focusing on 11 core vaccines recommended by the World Health Organization (WHO). These include vaccines against diphtheria, tetanus, whooping cough (pertussis), measles, polio, and tuberculosis.
According to the study, between 1980 and 2023, global vaccine coverage more than doubled for these diseases. The number of “zero-dose” children those who had never received any routine childhood vaccine dropped from 58.8 million in 1980 to 14.7 million in 2019.
However, progress has stalled or reversed in many parts of the world since 2010. The study found that measles vaccination rates declined in 100 out of 204 countries between 2010 and 2019. Additionally, 21 out of 36 high-income countries experienced declines in coverage for at least one of the vaccines studied.
The COVID-19 pandemic further impacted global immunisation efforts. From 2020 to 2023, an estimated 15.6 million children missed the full three doses of the diphtheria-tetanus-pertussis (DTP) vaccine or a measles vaccine. Around 16 million children did not receive any polio vaccine, while 9.18 million missed the tuberculosis vaccine.
The pandemic years also saw an additional 12.8 million zero-dose children globally.
“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 Dr Jonathan Mosser, senior author of the study from IHME.
He added that, in addition to global inequalities and the impact of the pandemic, “the growth of vaccine misinformation and hesitancy also contributed to faltering immunisation progress.”
The study also found that more than half of the 15.7 million unvaccinated children in 2023 lived in just eight countries primarily in sub-Saharan Africa (53 per cent) and South Asia (13 per cent): Nigeria, India, the Democratic Republic of Congo, Ethiopia, Somalia, Sudan, Indonesia, and Brazil.
“These trends increase the risk of outbreaks of vaccine-preventable diseases, including measles, polio, and diphtheria, underscoring the critical need for targeted improvements to ensure that all children can benefit from lifesaving immunisations,” Mosser noted.
The researchers emphasised the urgent need to strengthen routine childhood vaccination systems, close immunisation gaps, and improve equitable access through increased investments and focused strategies.
