15.6 Million Young Children Caught Measles in 2023, a Study Says
A global study estimates that 15.6 million children under five caught measles in 2023. Two doses of a long-established vaccine can prevent outbreaks, but coverage remains far below the level needed.
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Measles cases among children under five rose 40% between 2019 and 2023, a global study estimates, reversing decades of progress as vaccination left millions unprotected. [2]
The study, published in Nature Medicine on October 21, 2026, estimates that 15.6 million young children had measles in 2023 and 118,000 died from it. Deaths rose 12% over the same four-year period. Sub-Saharan Africa and South Asia carried the highest burden. [2]
The findings put numbers to a dangerous reversal: an airborne disease that can spread from one infected person to as many as 18 others is finding gaps in protection. The World Health Organization says preventing outbreaks requires at least 95% coverage with two vaccine doses in every country and community. Its latest figures put worldwide two-dose coverage at 77% in 2025. [3][4]
COVID-era disruption of public-health programmes and their funding contributed to falling vaccination rates, according to Nature's November 2 research summary. The new study documents the resurgence alongside lower or stagnant coverage, rather than establishing how much of the increase the pandemic caused. [1][2]
The immediate task is familiar: reach children who missed vaccination and complete their two-dose protection. WHO says the vaccine is safe, effective and inexpensive, has been used for about 60 years and costs less than US$1 per child. [4]
A long retreat, then a sharp reversal
The GBD 2023 Measles Collaborators examined disease burden and vaccination among children under five across 204 countries and territories, covering 1990 to 2023. That long view shows how much ground had been gained before the reversal. [2]
Global measles incidence fell by about 80% between 1990 and 2019, while mortality fell by about 90%, according to the study. Both rebounded sharply after 2020. [2]
Vaccination had expanded substantially during those earlier decades. The researchers estimate that first-dose coverage rose from 67.2% in 1990 to 83.6% in 2019. By 2023, it had slipped to 81.0%, a drop of 2.6 percentage points. [2]
Second-dose coverage followed a different path. It rose from 14.4% in 1990 to 68.4% in 2019 and reached 71.4% in 2023. Completion improved, but remained well short of the coverage needed to prevent outbreaks. [2][3]
Those two trajectories matter. The reversal cannot be described as every measure of vaccination collapsing: first-dose protection slipped, while second-dose coverage continued to rise. Neither reached enough children.
The practical problem is both getting children into vaccination programmes and ensuring they receive the second dose.
The outbreak record shows the consequences extending across borders. WHO and the US Centers for Disease Control and Prevention reported large or disruptive measles outbreaks in 57 countries in 2023, up from 36 in 2022. Nearly half were in the WHO African Region. [3]
That is 21 additional countries in a year. A regional concentration of illness had become a problem shared by dozens of national health systems. [3]
Two estimates, one clear warning
The new study's figures are modelled estimates, not a direct count of every infection. They are also higher than a separate WHO-CDC assessment, published in November 2024, which estimated 10.3 million cases and 107,500 deaths worldwide in 2023 across all ages. Why the estimates differ has not been explained, so they should not be combined into a single tally. [2][3]
The WHO-CDC assessment nevertheless identified a substantial vaccination shortfall of its own. It estimated that more than 22 million children missed their first measles vaccine dose in 2023. Its coverage estimates were 83% for the first dose and 74% for the second. [3]
The latest WHO fact sheet provides a more recent snapshot: in 2025, 84% of children received a first dose and 77% received both doses. Those figures cover a different year and come from a separate assessment from the GBD study, whose series ends in 2023. [4]
Even the more recent two-dose figure is 18 percentage points below WHO's 95% outbreak-prevention threshold. And a global average cannot satisfy a target that must be reached community by community. High coverage elsewhere does not close a local vaccination gap. [3][4]
The study also found several regions below the Immunization Agenda 2030 target of 90% vaccine coverage. That programme target and WHO's 95% measles threshold are different benchmarks. Meeting the former would still leave work to do against a virus this contagious. [2][3]
The vaccine is ready. Delivery is the test.
Measles spreads through the air and can cause pneumonia, blindness and encephalitis, an inflammation of the brain. Young children face particular risk from its complications. This is why a missed vaccination is more than an unfinished entry in a health record. [4]
The record of prevention is enormous. WHO estimates that measles vaccination prevented 59 million deaths between 2000 and 2024. The intervention behind that gain is already established: children need two doses. [4]
The priority is to restore reliable routine vaccination while reaching children already missed. Improving the worldwide average matters, but success must be measured where children live, against the coverage needed to keep an outbreak from taking hold.
The next test is whether newer surveillance shows the resurgence continuing and whether immunization programmes can close those local gaps. WHO's latest coverage figures still leave almost a quarter of children without both doses. [4]
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- Measles made a stealthy return as another virus took the spotlight | Nature Nature
- Global and regional burden of measles and vaccine coverage among children under 5 years, 1990−2023: a Global Burden of Disease Study | Nature Medicine nature.com
- Measles cases surge worldwide, infecting 10.3 million people in 2023 who.int
- Measles who.int