The number of confirmed measles cases in the United States reached 733 in the first weeks of 2026, according to the Centers for Disease Control and Prevention (CDC). This increase quadruples the annual average recorded since the elimination of the virus in the country and affects communities with low rates of child vaccination.
According to the most recent CDC report, measles infections are concentrated in more than twenty states, with a notable incidence in South Carolina, where more than 500 infections were reported. The federal agency attributes the spread to the decline in the coverage of the measles, mumps, and rubella (MMR) vaccine and the increase in outbreaks in sectors with insufficient immunization.
The context of this outbreak dates back to the sustained decrease in the vaccination rate in minors. According to the CDC, the national coverage of the MMR vaccine dropped from 95% in 2019 to less than 93% in 2025, below the recommended threshold to maintain herd immunity and prevent sustained circulation of the virus.
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How many measles cases have been confirmed in the United States in 2026?
The United States has confirmed 733 measles cases between January and the first days of February 2026, according to official data published by the CDC on its infectious disease portal. This figure represents a noticeable increase compared to the average of 180 annual cases that the country used to record since the year 2000, when the elimination of the endemic transmission of the virus was declared.








