Measles, a highly contagious virus, is making a comeback in various parts of the world, including the U.S., Canada, Mexico, South America, and Europe. In 2025, North and South America saw a significant increase in measles cases, with rates 11 times higher than the previous year. In Europe, measles rates have reached a 25-year high.
In the United States, health authorities have reported 935 cases of measles affecting 30 states as of May 2, 2025. This surge is a stark comparison to the 285 cases reported in 2024. Canada is also experiencing a large measles outbreak, with over 1,000 cases reported.
The rise in measles cases has prompted concerns among experts, including Rebecca Schein, a specialist in pediatric infectious diseases. She explains that the spike in measles cases domestically and internationally could have significant implications for a disease that was declared eliminated in the U.S. in 2000.
From 2000 to 2010, the U.S. reported fewer than 100 measles cases annually. However, since 2010, isolated outbreaks have occurred, mainly in unvaccinated communities, with approximately 200 to 300 cases reported each year. The most significant outbreak in recent years occurred in 2019, with 1,274 cases primarily in the New York City metropolitan area and parts of New Jersey.
While measles cases declined during the COVID-19 pandemic from 2020 to 2023, they have since returned to pre-pandemic levels in 2024 and continue to rise in 2025. The current surge in cases is primarily attributed to an epidemic in Texas, with 702 confirmed cases reported as of May 6.
The World Health Organization has declared both North and South America to be at high risk for measles. In Canada, there have been 1,177 reported cases, with 951 linked to an outbreak that began in New Brunswick in October 2024. Mexico has reported 421 confirmed cases of measles, with additional cases under investigation. South America is also experiencing small measles outbreaks, with countries like Belize, Brazil, and Argentina reporting cases.
In Europe, measles cases rose tenfold in 2024, reaching 35,212 cases, according to the European Centre for Disease Prevention and Control.
Measles was eliminated in the U.S. in 2000 through successful vaccination programs. However, the recent resurgence of measles is a cause for concern. Measles is highly contagious, with one infected person able to spread the virus to 12 to 18 others. Vaccination is crucial in preventing measles, with the MMR vaccine providing protection against measles, mumps, and rubella.
To achieve herd immunity and protect the community, 95% of the population must be vaccinated. However, vaccination rates have been declining globally, posing a significant challenge in controlling the spread of measles. The decrease in vaccination rates, especially during the COVID-19 pandemic, has contributed to the rise in measles cases in the U.S. and other countries.
The resurgence of measles underscores the importance of vaccination programs and public health initiatives in combating infectious diseases. As measles cases continue to rise, health authorities and experts emphasize the importance of vaccination to prevent the spread of this highly contagious virus. In the wake of rising measles cases, infectious disease experts are expressing concern that the once-controlled infection may be on the verge of becoming endemic once again. Endemic infections are those that are consistently present within a particular region, much like the common cold and COVID-19 in the United States.
Measles outbreaks are defined as higher-than-normal cases in a specific area, with an outbreak declared when there are more than three cases in a county or local region. Should these cases spread beyond the local area, it escalates to an epidemic, and if the epidemic crosses international borders, it becomes a pandemic.
The recent measles outbreak in Texas, which began in January 2025, quickly escalated from an outbreak in six counties to an epidemic spanning 29 counties and totaling 702 cases by May 6. A study conducted in 2022 using a computer algorithm predicted the trajectory of measles cases in the US due to a drop in vaccination rates during the pandemic.
The study suggested that if children who missed vaccinations during the pandemic do not receive catch-up vaccines and vaccine hesitancy persists, approximately 15 million US children (21%) could be vulnerable to measles over the next five years. This number falls short of what is needed to prevent measles outbreaks.
A more recent study published in April 2025 further reinforced the likelihood of measles becoming endemic in the US again, projecting 850,000 cases over the next 25 years if vaccination rates remain stagnant. However, if vaccination rates decline further, the number of cases could surge to 11 million over the same period.
To reverse this alarming trend, a consistent increase in community vaccination rates is imperative. The April 2025 study suggested that boosting community vaccination rates by just 5% could significantly curb the rise in measles cases over the next 25 years. Another epidemiological model highlighted the importance of early intervention in outbreaks with the support of local health departments, emphasizing the need for at least 85% of the population to be vaccinated to contain measles outbreaks.
Ultimately, addressing the resurgence of measles requires sustained access to free and accessible childhood vaccinations and the restoration of public trust in measles vaccines. It is crucial to prioritize vaccination efforts and public health measures to prevent measles from regaining its endemic status in the US.
This article was written by Rebecca Schein, Assistant Professor of Infectious Disease Pediatrics at Michigan State University, and is republished from The Conversation under a Creative Commons license. The COVID-19 pandemic has brought about unprecedented changes to the way we live, work, and interact with one another. As we continue to navigate through this challenging time, it is important to reflect on the impact that the pandemic has had on our society as a whole.
One of the most significant changes that has occurred as a result of the pandemic is the shift towards remote work. With many businesses forced to close their physical offices and transition to a work-from-home model, employees have had to adapt to a new way of working. This has presented both challenges and opportunities, as individuals have had to find ways to stay productive while also balancing the demands of their personal and professional lives.
The pandemic has also highlighted the importance of technology in our daily lives. From video conferencing platforms to online shopping services, technology has played a crucial role in helping us stay connected and informed during these difficult times. As we continue to rely on technology for work, school, and socializing, it is clear that digital tools will continue to shape the way we live and work in the future.
In addition to the changes in our work and technology use, the pandemic has also had a profound impact on our mental health. The stress and uncertainty of the situation have taken a toll on many individuals, leading to feelings of anxiety, depression, and isolation. It is more important than ever to prioritize self-care and seek support when needed to maintain our mental well-being during this challenging time.
Despite the challenges that the pandemic has brought, it has also shown the resilience and strength of our communities. From frontline workers risking their lives to keep us safe, to neighbors coming together to support one another, we have seen countless examples of kindness and compassion in the face of adversity. As we continue to navigate through this difficult time, it is important to remember the power of community and the importance of coming together to support one another.
In conclusion, the COVID-19 pandemic has brought about significant changes to our society, from the way we work and use technology to the impact on our mental health. As we continue to face these challenges, it is important to stay connected, prioritize self-care, and support one another as we work towards a brighter future. By coming together and showing compassion and resilience, we can overcome this difficult time and emerge stronger than ever before.
