Measles activity remains an ongoing public health concern throughout the United States, as outbreaks continue to occur. Nationally, the Centers for Disease Control and Prevention (CDC) has reported 2,281 confirmed measles cases in 2025 and 982 confirmed cases in 2026 (as of February 25, 2026)with most cases linked to outbreaks.
Measles is highly contagious and spreads through airborne transmission, placing infants too young to be fully vaccinated, pregnant people, and immunocompromised patients at increased risk. Early identification, immediate isolation, and strong vaccination practices remain central to limiting transmission in healthcare and community settings.
Epidemiology of the Current Outbreak:
- As of February 25, 2026, the CDC reported 982 confirmed measles cases in 2026, with 90% of cases being associated with outbreaks.
- In 2026, measles cases were reported in 24 jurisdictions, including Arizona, California, Colorado, Florida, Georgia, Idaho, Kentucky, Maine, Minnesota, Nebraska, New York City, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, South Dakota, Utah, Vermont, Virginia, Washington, and Wisconsin.
- The CDC reported 2,281 confirmed measles cases in 2025 among 45 jurisdictions, with 89% of cases related to outbreaks
Clinical Manifestations of Measles
According to the CDC, measles initially presents with a high fever (may exceed 104 degrees Fahrenheit), cough, runny nose, and conjunctivitis (red, watery eyes), symptoms that can be mistaken for common viral infections. Within 2-3 days, Koplik spots, which are tiny, bluish-white spots, may appear inside the mouth. Within 3-5 days, a characteristic maculopapular rash emerges, which consists of flat, red spots (macules) and small, raised bumps (papules). This rash typically begins on the face before progressing downward across the body.
While many individuals recover from measles, it can lead to severe complications, particularly in children under five years of age and immunocompromised individuals. Pneumonia, an infection of the lungs, is the leading cause of measles-related deaths in young children. Encephalitis, an infection that causes brain swelling, can result in permanent brain damage.
Additionally, a rare but fatal complication known as subacute sclerosing panencephalitis (SSPE) may develop 7 to 10 years after the initial infection, causing progressive neurological decline. These risks highlight the importance of vaccination, which remains the most effective preventive measure against measles.
Transmission Dynamics
Measles is a highly contagious viral infection that spreads through respiratory droplets; this occurs when an infected person coughs or sneezes and someone breathes the air previously exhaled by someone with measles. The virus can remain in the air and on surfaces for up to two hours, making it easily transmissible in shared spaces like schools and healthcare settings.
An individual with measles is infectious from four days before the rash appears to four days after its onset, allowing the virus to spread before symptoms manifest. Measles has a 90% transmission rate among unvaccinated individuals who come into contact with an infected person. Due to its fast transmission, maintaining high vaccination coverage is crucial to preventing outbreaks.
Vaccination: The Cornerstone of Prevention
The measles, mumps, and rubella (MMR) vaccine is recognized as the most effective method for preventing measles outbreaks. According to the CDC, a single dose provides approximately 93% protection. In comparison, administering two doses enhances immunity to around 97%, offering lifelong protection in most cases.
To mitigate widespread transmission, at least 95% of the population must be vaccinated to achieve herd immunity, thereby protecting individuals who cannot receive the vaccine, such as infants and those with immunocompromising conditions. However, recent data indicates that U.S. MMR vaccination rates have declined for children by age 24 months, falling below the critical threshold required for herd immunity.
This decline has contributed to increased outbreak vulnerability across multiple jurisdictions, particularly in communities with low vaccination coverage. Enhancing vaccination rates is imperative to curtailing the spread of this highly contagious disease and preventing unnecessary morbidity and mortality.
Who Should Consider an Additional MMR Dose (Booster Vaccination)
Most individuals who received the routine two-dose MMR series in childhood have durable immunity and do not require routine booster doses. However, adults and adolescents without documentation of two doses or without laboratory evidence of immunity should receive vaccination.
Groups commonly advised to ensure two documented MMR doses include healthcare personnel, students in post-secondary settings, international travelers, and women of childbearing age who lack evidence of immunity. Additionally, individuals vaccinated between 1963 and 1967 may have received an inactivated measles vaccine with lower effectiveness and should receive at least one dose of MMR if vaccination history is uncertain.
During outbreaks, public health authorities may recommend an additional MMR dose for specific exposed or higher-risk groups as part of targeted outbreak control measures. Healthcare professionals should assess immunization history, risk factors, and local public health guidance when counseling patients.
Impact of Declining Vaccination Rates
Vaccination rates have declined significantly since the COVID-19 pandemic, leading to a resurgence of vaccine-preventable diseases like measles. In Gaines County, Texas, the percentage of kindergartners claiming vaccine exemptions has more than doubled from 7.5% a decade ago to around 18% last school year. This rise reflects a national trend of falling childhood vaccination rates.
The consequences are severe. Measles cases have increased, resulting in more hospitalizations, complications, and deaths among unvaccinated individuals. The highly contagious nature of measles makes low vaccination coverage a serious public health threat. Without urgent action to restore immunization rates, communities could face preventable outbreaks, higher healthcare burdens, and increased mortality rates.
Misinformation remains a significant challenge for vaccination efforts, particularly the claim that the MMR vaccine is linked to autism. This misconception originated from a discredited study published in 1998, which has been thoroughly debunked by extensive research that demonstrates no connection between the MMR vaccine and autism.
Vitamin A: Important Safety Considerations (Avoiding Overdose)
Vitamin A is not a substitute for vaccination and does not prevent measles. The American Academy of Pediatrics (AAP) cautions that promoting vitamin A as a preventive measure can lead to delayed vaccination and unsafe dosing.
In clinical care, vitamin A may be used only under a clinician's supervision for select pediatric patients who are already ill (often in settings where deficiency is more likely). Outside of that context, high-dose supplementation can cause toxicityespecially in children. Signs and symptoms of vitamin A overdose may include nausea/vomiting, headache, fatigue, joint/bone pain, blurry vision, and skin/hair changes, with severe complications such as increased intracranial pressure, liver damage, coma, and (during pregnancy) risk of birth defects.
Public Health Interventions
The CDC emphasizes rapid case identification, immediate reporting, and coordinated outbreak response. Clinicians should promptly report suspected measles cases to local or state health departments and follow jurisdiction-specific guidance for testing, airborne isolation, and exposure management.
Core outbreak control measures include contact tracing to identify exposed individuals and determine the need for quarantine or post-exposure prophylaxis. Eligible contacts may receive the MMR vaccine within 72 hours of exposure or immune globulin within six days, depending on risk factors and immune status. Infected individuals should remain isolated for at least four days after rash onset to reduce transmission.
Healthcare settings should implement airborne precautions immediately when measles is suspected, including placement in a negative-pressure room when available. Staff should verify their own immunity status and ensure appropriate use of personal protective equipment.
Beyond acute outbreak response, strengthening routine immunization programs remains essential. Expanding vaccine access, reducing logistical barriers, and supporting community education efforts can help improve vaccination coverage and reduce the likelihood of future outbreaks. Policy discussions regarding exemption standards and immunization requirements continue to be part of broader public health strategies to maintain herd immunity.
Supporting Data on the Importance of Immunization
Measles was once a leading cause of childhood mortality, according to the CDC, with 400 to 500 deaths, 48,000 hospitalizations, and 1,000 cases of encephalitis occurring annually in the United States prior to the introduction of the vaccine in 1963.
The development and widespread administration of the measles vaccine resulted in a 99% reduction in cases across the United States, effectively eliminating endemic measles transmission by the year 2000.
On a global scale, vaccination efforts have been crucial in reducing measles mortality. Between 2000 and 2018, measles deaths decreased by 73%, from 535,600 to 142,300, due to expanded immunization programs. However, recent declines in vaccine coverage have led to a resurgence of measles cases, underscoring the importance of maintaining high immunization rates to prevent future outbreaks.
Conclusion
Current measles activity emphasizes the dangers of decreasing vaccination rates. The MMR vaccine is highly effective, providing 97% protection with two doses.
Healthcare professionals play a key role in addressing misinformation and facilitating the implementation of public health measures. Advocacy for immunization, support for relevant policies, and ensuring vaccine accessibility are important components of public health strategy. Building trust in vaccines is associated with the prevention of future outbreaks and may contribute to saving lives.
Understanding measles is crucial for healthcare professionals and the public alike. To further explore the history, transmission, symptoms, prevention, and management of measles, CEUfast offers a free course: Measles in a Modern World.
About the Author:
Nicole Ricketts-Murray is a registered nurse (RN) who has a passion for traveling and discovering new places. With 17 years of experience in the field of nursing and a multistate nursing license, she is a highly qualified professional. Apart from her professional expertise, she is also an avid writer and enjoys sharing her insights and experiences with others.
Nicole is an independent contributor to CEUfast's Nursing Blog Program. Please note that the views, thoughts, and opinions expressed in this blog post are solely of the independent contributor and do not necessarily represent those of CEUfast. This blog post is not medical advice. Always consult with your healthcare provider for any health-related questions or concerns.
If you want to learn more about CEUfast's Nursing Blog Program or would like to submit a blog post for consideration, please visit https://ceufast.com/blog/submissions.
