Measles resurgence exposes post-pandemic cracks in childhood vaccination

Measles cases rose by 40% between 2019 and 2023 as immunisation disruptions left 23.7 million infants without a first dose, researchers found.

A new study has found that childhood measles vaccination is sliding backwards in the years after the COVID-19 pandemic, with routine immunisation disruptions and strained health systems helping to drive a global resurgence of the disease. Researchers from the University of Queensland analysed measles cases, deaths and vaccine gaps in children under five across 204 countries and territories from 1990 to 2023, and estimated that cases rose by 40% from 11.1 million in 2019 to 15.6 million in 2023. The findings, published in Nature Medicine, suggest that gains made over decades are being eroded just as health services in many places remain vulnerable to future shocks.

Measles is highly contagious and can be dangerous, particularly for young children. The World Health Organisation says a single case can produce up to 18 secondary infections in populations with low immunity, while earlier research in The Lancet Global Health estimated that in low- and middle-income countries the disease was fatal in as many as three in every 100 infected infants under one year old in 2019. The CDC and WHO reported in 2024 that global measles cases reached an estimated 10.3 million in 2023, a 20% increase from 2022, reflecting persistent gaps in vaccination coverage.

Associate Professor Benn Sartorius, of UQ’s Frazer Institute, said the post-pandemic pattern had undone years of progress. “This has contributed to a global resurgence of measles in young children,” Sartorius said. “It backtracks on decades of progress, where a nearly 80% decline in measles cases was recorded worldwide between 1990 and 2019.” He added that the disease’s return followed COVID-related disruption to immunisation programmes, health systems and funding, and warned that under-resourced regions remain the most exposed. The study said an estimated 23.7 million infants, or about one in five, missed their first measles dose in 2023, with sub-Saharan Africa accounting for half of those missed vaccinations and South Asia for another 20%.

The research also points to the risk of complacency in higher-income countries. In the United States, CDC data show measles cases had climbed sharply by October 1, 2026, while vaccination coverage for measles, mumps and rubella among kindergartners has fallen from 95% to 92%, according to the study’s summary. In Europe, the European Centre for Disease Prevention and Control said there were 2,361 measles cases across 30 EU and EEA countries in 2023, a level above the previous three years but still below 2019. Sartorius said recent outbreaks in the US showed that the virus can re-emerge wherever immunity gaps are allowed to widen.

Australasia was one of the stronger performers in the analysis. The study found that the region recorded one of the biggest gains in second-dose measles coverage between 1990 and 2019, and by 2023 had the highest estimated coverage of any region, at 96% among children under five. Sartorius said the data could help authorities identify undervaccinated groups and direct catch-up campaigns more effectively. “We hope the data from our study will be used to target catch-up vaccination efforts and strengthen immunisation where support is needed most,” he said.