A sweeping global health study has revealed that eight countries — Nigeria, India, Democratic Republic of Congo, Ethiopia, Somalia, Sudan, Indonesia, and Brazil — are home to over half of the world’s unvaccinated children as of 2023. The research, published in The Lancet and led by the Institute for Health Metrics and Evaluation at the University of Washington, underscores how immunization efforts have regressed following the COVID‑19 pandemic, leaving millions of young lives at risk.
The findings show that global vaccination coverage, which experienced a significant setback during the pandemic, has failed to rebound to pre‑2020 levels. In 2023, an estimated 15.6 million children missed essential vaccines against diphtheria, tetanus, and pertussis (DTP), as well as essential measles inoculations. Nearly 16 million children also remained unprotected by the polio vaccine, with 9 million skipping the tuberculosis shot.
India bore a disproportionate share of this burden. Of the approximately 15.7 million zero‑dose children globally—which is defined as those who have received no doses of basic vaccines—over half were in the eight identified countries. Within this half unvaccinated children group, India and Nigeria emerged as critical hotspots. Specifically, India ranked second with nearly 1.6 million zero‑dose children in 2023, up from 1.392 million in 2022—an alarming increase of 600,000 compared to the previous year.
Sector experts emphasize that these setbacks are not only a matter of public health but also of deep inequities. Many of the unvaccinated children reside in regions hit by conflict, poverty, and interrupted healthcare services. The stagnation wasn’t limited to low‑income nations; even some high‑income countries witnessed worrying trends. For instance, Australia ranked among the lowest in childhood vaccination coverage within its economic bracket, reporting a 92.9% coverage—just above New Zealand’s 92.5%—and ranking as the sixth worst performer in raw numbers of unvaccinated children.
Public health authorities have been alerted to an uptick in vaccine hesitancy and misinformation that compounds logistical and systemic issues. In 2023, measles coverage plateaued at 83%, well below the 95% threshold required to prevent outbreaks. Alarmingly, over three‑quarters of infants worldwide live in areas where coverage drops to 80% or less, creating fertile ground for resurgent epidemics. Indeed, measles cases surged across more than 100 countries, with globally confirmed cases nearly tripling within a year .
Dr. Tedros Adhanom Ghebreyesus, director-general of WHO, described measles outbreaks as “the canary in the coalmine” — a stark indicator of failing immunization systems. Further, WHO and UNICEF noted that in fragile or war‑torn regions, basic vaccination programs have collapsed, exacerbating vulnerabilities.
The situation is not irreversible. Governments and global alliances point to targeted initiatives as paths forward. India’s own “Mission Indradhanush” and its intensified strategies—which targeted districts with large numbers of zero‑dose children—have demonstrated success in raising coverage. UNICEF India highlighted that over 98% of Indian parents still value vaccines, signaling social trust that can be leveraged to recover lost ground.
Yet, the challenges remain vast. According to WHO and UNICEF’s 2024 data, the number of zero‑dose children climbed from 13.9 million in 2022 to 14.5 million in 2023—a regression to coverage levels last seen in 2019. Global DTP‑3 vaccine coverage stagnated at around 84%, down from 86% in 2019.
Health authorities are calling for renewed commitment: increased funding, community engagement, dismantling of vaccine misinformation, and reinforced healthcare delivery, especially in neglected regions. Achieving and maintaining the immunization targets set out in the “Immunization Agenda 2030”—which aims for at least 90% coverage and fewer than 6.5 million zero‑dose children worldwide—will require substantial political and financial will.
Without urgent action, millions of children risk falling prey to preventable diseases such as measles, polio, and whooping cough. Global health experts warn that the current decline in vaccination coverage, about half of world’s total, could trigger a surge in epidemics, undoing decades of public health progress and threatening millions of vulnerable children worldwide.
