Global Measles Surge: Declining Vaccination Rates Fuel Renewed Threat
A resurgent wave of measles is sweeping across the globe, driven by falling vaccination rates and disruptions to healthcare systems. The highly contagious and potentially deadly virus is impacting populations worldwide, with significant increases reported in Europe, the Eastern Mediterranean, and the United States.
The resurgence is rooted in a confluence of factors, including the setbacks to immunization programs caused by the COVID-19 pandemic and the growing influence of anti-vaccine movements. Health officials warn that even countries with historically high vaccination coverage, like Spain, are now experiencing a rise in cases.
Worldwide Increase in Cases
The scale of the outbreak is alarming. In the Eastern Mediterranean region, measles cases surged by 84% in 2024. Europe saw a 47% increase during the same period. The United States experienced a dramatic jump, with reported cases climbing from approximately 300 in 2024 to over 2,000 last year.
Even Spain, declared free of endemic measles circulation by the World Health Organization (WHO) in 2017, is not immune. According to epidemiological data from the Carlos III Health Institute, nearly 397 cases were recorded in 2025, nearly double the 217 reported in 2024 and a stark contrast to the 11 cases seen in 2023.
“What is happening in Spain is a reflection of what is happening outside,” explained a researcher at the National Epidemiology Center of the Carlos III Health Institute (ISCIII). “Viruses do not understand borders and circulation outside our territory has greatly increased. It is a great global concern and what we receive are imported cases that generate outbreaks. The only way to stop it is to have high vaccine coverage.”
The Role of Declining Vaccine Coverage
At the heart of the problem lies a decline in vaccination rates. The WHO recommends coverage above 95% with two doses of the measles vaccine to maintain herd immunity. However, coverage levels vary significantly between countries and have been generally decreasing.
Experts point to two primary drivers: the disruption of vaccination campaigns during the COVID-19 pandemic, which diverted resources from routine immunizations, and the increasing prevalence of vaccine hesitancy fueled by misinformation. A microbiologist at the Hospital Clínic of Barcelona added that a decrease in immunity over time, due to limited circulation of the wild virus, may also be contributing.
The consequences of even slight declines in coverage can be severe. Romania, where vaccination coverage has plummeted to 62%, serves as a stark example. The country accounted for 87% of the 35,000 measles cases reported across the European Union in 2024.
Spain’s Situation: Vigilance and High Coverage
Despite the global trend, Spain currently maintains relatively high vaccination coverage, with 96% of the population receiving one dose of the MMR vaccine and 93.2% receiving two. Health authorities remain vigilant, responding quickly to suspected cases to prevent further transmission.
“If we are not seeing thousands of cases in Spain right now, it is because we have been systematically vaccinating for decades,” stated a deputy director general of Public Health Surveillance and Emergency Response of the Generalitat of Catalonia. However, epidemiologists acknowledge the existence of “pockets of susceptibles” – individuals at risk due to lack of vaccination, including recent immigrants from countries with lower coverage or those who have chosen not to vaccinate.
The Ministry of Health recommends the MMR vaccine for all individuals born after 1978, as those born before are generally considered protected due to prior exposure to the disease. Experts emphasize that vaccination remains the most effective way to prevent measles, with minimal risk of adverse effects. While rare cases of vaccine failure can occur, the disease is typically milder and less transmissible in vaccinated individuals.
Early 2025 Outbreaks and Ongoing Monitoring
The start of 2025 has already seen several measles outbreaks in Spain, including active infections in Bizkaia, Toledo, and Malaga. Following the summer, 13 cases were reported in Sant Pere de Ribes, Barcelona. A spokesperson for the Catalan Government attributed these outbreaks to “beliefs deniers that make people not get vaccinated.”
While some experts express concern about potential declines in coverage, others believe Spain is relatively resilient to misinformation. However, a pediatrician and member of the Spanish Association of Vaccinology cautioned that some regions – including the Balearic Islands, the Canary Islands, and Aragon – have coverage rates below 90%, requiring increased attention.
A Global Crisis with Serious Consequences
The WHO estimates that approximately 11 million measles infections occurred worldwide in 2024, an increase of nearly 800,000 compared to 2019. Despite the availability of a safe and effective vaccine, an estimated 95,000 people died from measles that year.
The WHO has noted that recent outbreaks are disproportionately affecting regions with improved nutrition and healthcare access, suggesting that even in settings where mortality rates are lower, measles can still cause serious, long-term complications such as blindness, pneumonia, and encephalitis. There are currently no specific antiviral treatments for measles, underscoring the critical importance of prevention through vaccination.
The global measles surge serves as a stark reminder of the fragility of public health and the vital role of vaccination in protecting communities from preventable diseases. Continued vigilance, increased vaccine coverage, and a commitment to combating misinformation are essential to stemming the tide and preventing further outbreaks.
