The United States is experiencing a concerning resurgence of measles, a highly contagious viral illness that public health officials had hoped to eliminate. As of , the Centers for Disease Control and Prevention (CDC) has reported 982 confirmed cases of measles nationwide for 2026, a significant increase compared to previous years. This rise is prompting renewed concern among healthcare professionals and a re-evaluation of vaccination strategies.
The current outbreak is not isolated. Data from the CDC indicates that cases are reported across 26 jurisdictions, including Arizona, California, Florida, Georgia, Illinois, Kentucky, Maine, Minnesota, Nebraska, New York City, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, South Dakota, Texas, Utah, Vermont, Virginia, Washington and Wisconsin. An additional 6 cases have been identified in international visitors to the U.S. Notably, 89 percent of confirmed cases – 870 out of 982 – are associated with ongoing outbreaks, with 73 originating in 2026 and 797 stemming from outbreaks that began in 2025.
To put this into perspective, in all of 2025, the U.S. Recorded a total of 2,281 confirmed measles cases across 45 jurisdictions, with 25 cases among international visitors. There were 49 outbreaks reported that year, and, similar to 2026, approximately 89 percent of cases were linked to these outbreaks.
The dramatic increase from 285 cases in 2024 to over 1,319 cases by , as reported in a recent publication in the International Journal of Surgery, underscores the fragility of herd immunity. Herd immunity occurs when a sufficiently high percentage of the population is immune to a disease – through vaccination or prior infection – making its spread unlikely. When vaccination rates decline, as has been observed in some communities, the risk of outbreaks increases.
Measles is exceptionally contagious. The reproduction number (R0) – a measure of how many people, on average, one infected person will infect in a completely susceptible population – for measles is between 12 and 18. This means that one person with measles can infect a large number of others. The virus is spread through respiratory droplets produced when an infected person coughs or sneezes.
While often perceived as a childhood illness, measles can lead to serious complications, including pneumonia. In rare cases, it can cause subacute sclerosing panencephalitis (SSPE), a fatal neurological condition that develops years after the initial infection. The resurgence of measles is raising concerns that healthcare providers may once again encounter these severe complications, which were less common during periods of high vaccination coverage.
The current situation highlights the importance of vaccination. The measles, mumps, and rubella (MMR) vaccine is highly effective in preventing measles. Two doses of the MMR vaccine are recommended for all children, with the first dose typically administered between 12 and 15 months of age and the second dose between 4 and 6 years of age. Vaccination is also recommended for adults who have not previously been vaccinated or who are unsure of their vaccination status.
The potential loss of measles elimination status in the U.S. Is a significant concern. Elimination means that the disease is no longer continuously transmitted within a defined geographic area. Maintaining elimination requires high vaccination coverage and robust surveillance systems to quickly identify and respond to any imported cases. Without a coordinated response, the U.S. Risks reversing decades of progress against vaccine-preventable diseases.
Public health officials are urging individuals to review their vaccination records and ensure they are up-to-date. They are also emphasizing the importance of staying home if you are feeling sick and contacting your healthcare provider if you suspect you may have measles. Symptoms of measles include fever, cough, runny nose, and a characteristic rash that typically appears 3 to 5 days after the onset of fever.
The CDC provides resources for communities experiencing measles outbreaks, including sample letters to inform the public and toolkits to help prepare for and respond to outbreaks. The current situation serves as a stark reminder of the ongoing threat posed by vaccine-preventable diseases and the critical role of vaccination in protecting public health.
