Rising Threat of Measles in the U.S. Linked to Declining Vaccination Rates

A recent study highlights the alarming trend of decreasing vaccination rates among children in the United States, which poses a significant risk of measles outbreaks and the resurgence of other previously controlled diseases. Researchers from Stanford Medicine Institute and other universities conducted a simulation study published in the Journal of the American Medical Association (JAMA), predicting millions of potential infections over the coming years.

The study utilized a computer model to analyze the spread of diseases such as measles, rubella, polio, and diphtheria under various vaccination scenarios. Key factors considered included population growth, existing immunity levels, and the risk of importing infectious diseases. The analysis drew on vaccination data from 2004 to 2023.

Current estimates suggest that, if vaccination rates remain as they are, the U.S. could see approximately 850,000 measles cases, leading to 170,000 hospitalizations and 2,500 deaths over the next 25 years. The lead author of the study warned that a mere 10% decline in vaccination rates could escalate measles cases to 11.1 million in the same timeframe.

If these rates continue to fall, diseases that were once eliminated in the U.S., such as rubella and polio, may re-emerge. A hypothetical scenario where vaccination rates are halved could result in over 51 million measles cases, 9.9 million rubella cases, 4.3 million polio cases, and 200 diphtheria cases within 25 years. Such an increase would likely lead to 10.3 million hospital admissions and approximately 159,200 fatalities.

The lead researcher, Nathan Lo, emphasized the importance of increasing vaccination rates by even a modest five percent to prevent the sustained circulation of measles. He attributed the decline in routine vaccinations partly to the COVID-19 pandemic and the prevailing perception that these diseases are no longer a threat. Lo noted that there is a growing vaccine fatigue among parents and rising skepticism fueled by misinformation regarding vaccine safety and efficacy.

The resurgence of measles has been underscored by two recent fatalities of unvaccinated children in Texas, marking the first measles-related deaths in the U.S. in a decade. The majority of affected individuals in recent outbreaks have also been unvaccinated.

In a broader context, the issue of measles is not confined to the U.S. In Europe, the European Centre for Disease Prevention and Control (ECDC) reported ten measles-related deaths in 2024, primarily in Romania and Ireland. Globally, the World Health Organization (WHO) estimated that there were around 107,000 measles-related deaths in 2023, predominantly among under-vaccinated children under five.

Measles is a highly contagious viral disease transmitted through respiratory droplets. Individuals are infectious from five days prior to the onset of the characteristic rash, which follows symptoms resembling those of the flu, including high fever, cough, and runny nose. The only effective protection against the disease is through a two-dose vaccination schedule.

Complications from measles can severely impact the immune system, leading to conditions such as bronchitis, otitis media, or pneumonia. In severe cases, it can cause encephalitis, resulting in significant morbidity, with up to 20% of those infected facing mortality. Moreover, nearly one-third of cases can lead to long-term complications such as cognitive impairment or paralysis. Currently, there is no specific antiviral treatment available for measles.