The Growing Measles Outbreak in the U.S. and Global Concerns

The United States is facing a significant measles outbreak, with the number of confirmed cases surpassing 300 in 2025. According to the Centers for Disease Control and Prevention (CDC), 301 cases have been reported across 14 states, including Texas, New Mexico, California, and New York. This surpasses the 285 cases reported in all of 2024, highlighting the increasing spread of the disease. The majority of these cases—95%—are among individuals who are unvaccinated or whose vaccination status is unknown, emphasizing the critical role of vaccination in preventing measles.

The outbreak has already led to 50 hospitalizations and one confirmed death—a child in Texas who was unvaccinated. Another death under investigation in New Mexico further underscores the severity of the situation. The CDC has issued a measles advisory, urging travelers and healthcare professionals to remain vigilant. The agency also emphasizes the importance of ensuring full vaccination before travel and monitoring for symptoms upon return. Measles is highly contagious, and its spread is not limited to the U.S. Globally, the World Health Organization (WHO) and UNICEF reported over 127,000 measles cases in Europe in 2024—a number that has doubled since 2023 and represents the highest in nearly three decades. Worldwide, nearly 360,000 cases were reported in 2024, with more than half requiring hospitalization and 38 deaths in Europe alone.

Why Measles is Spreading: The Role of Vaccination and Immunity

Experts attribute the rapid spread of measles to its high contagiousness and declining vaccination rates in some communities. Measles is considered one of the most contagious diseases in the world—it can spread through the air or by direct contact with contaminated surfaces. Individuals with measles can transmit the virus up to four days before symptoms appear and up to 10 days after. This makes it challenging to contain outbreaks, especially in areas with low vaccination rates.

The CDC reports that 95% of measles cases in the U.S. are among unvaccinated individuals or those with unknown vaccination status. Fully vaccinated individuals are protected from severe illness and are unlikely to spread the disease. However, unvaccinated or immunocompromised individuals remain at significant risk. Pediatricians and infectious disease experts stress that measles is preventable only through vaccination. Unlike other illnesses, there are no alternative prevention methods—vitamin A, for example, cannot prevent measles but may help reduce the severity of symptoms in those already infected.

Dr. Danelle Fisher, a pediatrician, warns that if measles were to spread unchecked, it could rapidly circulate worldwide, similar to how COVID-19 spread before vaccines became available. However, she notes that vaccinations have played a crucial role in limiting the current outbreak’s spread. Dr. Fisher and other experts urge parents to ensure their children receive the recommended two doses of the measles, mumps, and rubella (MMR) vaccine. Adults who are unvaccinated or uncertain about their vaccination status are also encouraged to get immunized.

Protecting the Vulnerable: The Importance of Community Immunity

Measles outbreaks not only affect unvaccinated individuals but also pose a significant risk to those who cannot be vaccinated due to medical conditions, such as compromised immune systems or ongoing treatments. These individuals rely on community immunity, also known as herd immunity, to reduce their chances of exposure. When a large percentage of the population is vaccinated, it creates a “cocoon” of protection that makes it harder for the virus to spread.

Dr. William Schaffner, an infectious disease specialist, explains that individuals who are immunocompromised or have weakened immune systems are at a higher risk of severe complications from measles. These complications can include ear infections, pneumonia, and even long-term effects such as the loss of immune memory, which can leave individuals vulnerable to other infections they may have previously overcome. By ensuring high vaccination rates, communities can protect not only themselves but also those who are most vulnerable.

Preventive Measures Beyond Vaccination

While vaccination remains the most effective way to prevent measles, experts recommend additional precautions to reduce the risk of infection, especially for unvaccinated individuals. Dr. Fisher advises unvaccinated people to avoid nonessential travel, particularly on planes, trains, or other forms of mass transportation, where the risk of exposure is higher. She also suggests reducing contact with large groups of people, especially in settings like schools, healthcare facilities, or public gatherings.

For everyone, regardless of vaccination status, being mindful of symptoms such as coughs, rashes, or high fevers is crucial. Dr. Fisher encourages individuals to be cautious around anyone exhibiting these symptoms, as measles can spread quickly in crowded or poorly ventilated spaces. Even everyday activities, such as grocery shopping, can pose a risk as the outbreak grows. Staying informed about local cases and taking preventive measures can help reduce the spread of the virus.

The History of Measles and the Power of Vaccines

Before the widespread use of the measles vaccine in the mid-1950s, the disease caused over 3 million illnesses annually in the U.S., resulting in 48,000 hospitalizations and 500 deaths each year. The introduction of the vaccine marked a turning point in controlling the disease, but complacency and misinformation about vaccines have led to declining immunization rates in some areas. This has allowed measles to reemerge as a public health concern.

The CDC recommends that children receive two doses of the MMR vaccine—the first dose between 12 and 15 months of age, and the second between 4 and 6 years of age. Vaccination not only protects individuals but also prevents the spread of measles in communities. Dr. Anne Liu, a pediatric immunologist, emphasizes that measles is a preventable illness and urges families to prioritize vaccination. She also highlights the importance of raising awareness about the long-term consequences of measles, such as immune memory loss, which can leave individuals vulnerable to other infections.

A Call to Action: Staying Informed and Promoting Vaccination

The resurgence of measles in the U.S. and globally serves as a stark reminder of the importance of vaccination and community immunity. As the number of cases continues to rise, experts urge the public to remain vigilant and take proactive steps to protect themselves and others. Parents are encouraged to ensure their children are fully vaccinated, and unvaccinated adults are advised to consult their healthcare providers about receiving the MMR vaccine.

Community efforts to promote vaccination and combat misinformation are equally important. Dr. Schaffner suggests that individuals who know friends or family members who are hesitant to vaccinate their children should approach the topic with empathy and encourage them to speak with healthcare professionals. By fostering a sense of shared responsibility, communities can work together to prevent measles and other preventable diseases.

In conclusion, the growing measles outbreak is a wake-up call for individuals and communities to prioritize vaccination and take preventive measures. Measles is a highly contagious and potentially deadly disease, but it is also entirely preventable with the MMR vaccine. By staying informed, promoting vaccination, and protecting the most vulnerable, we can collectively reduce the impact of this outbreak and prevent future ones.