Key Points

The study led by researchers from the Institute for Health Metrics and Evaluation at the University of Washington, analysed coverage rates for 11 core vaccines for diseases like diphtheria, tetanus, whopping cough, and measles recommended by the World Health Organization (WHO) across 204 countries and territories.

The findings showed that between 1980 and 2023, worldwide vaccine coverage doubled against diseases such as diphtheria, tetanus, whooping cough (pertussis), measles, polio, and tuberculosis.

In addition, there was also a 75 per cent global decline in the number of children who had never received a routine childhood vaccine (also known as zero-dose children), falling from 58.8 million in 1980 to 14.7 million in 2019 before the Covid-19 pandemic.

But since 2010, progress has stalled or reversed in many countries. For example, measles vaccinations declined in 100 of 204 countries between 2010 and 2019, while 21 of 36 high-income countries experienced declines in coverage for at least one vaccine dose against diphtheria, tetanus, whooping cough, measles, polio, or tuberculosis, the research showed.

The Covid pandemic further exacerbated challenges, leading to sharp decline in global vaccine coverage.

The pandemic resulted in an estimated 15.6 million children missing the full three doses of the diphtheria-tetanus-pertussis vaccine or a measles vaccine between 2020 and 2023.

Nearly 16 million children also did not receive any polio vaccine, and 9.18 million missed out on the tuberculosis vaccine.

The four pandemic years (2020-2023) also saw around 12.8 million additional unvaccinated zero-dose children worldwide.

“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 from the Institute for Health Metrics and Evaluation (IHME), at the varsity.

Besides global inequalities and challenges from the Covid pandemic, “the growth of vaccine misinformation and hesitancy also contributed to faltering immunisation progress,” he added.

Further, the global study showed that in 2023, more than half of the world’s 15.7 million unvaccinated children were living in just eight countries. These were 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 global analysis called for a greater need to strengthen routine childhood vaccination coverage, boost investment and targeted strategies to maintain progress, close immunisation gaps, and ensure equitable access to life-saving vaccines.

- IANS