Measles cases in US surpass 2,777 in 2019, driven by declining vaccination rates

The United States is experiencing a severe resurgence of measles, with confirmed cases reaching 2,777 in August 2026. Driven by declining kindergarten vaccination rates—which fell to 92.5% in the 2024-2025 school year—outbreaks have flared in Utah, South Carolina, and Texas. Approximately 94% of cases occur in unvaccinated individuals, and multiple deaths have been reported. Medical experts warn of severe complications, including permanent blindness from keratitis, prompting ophthalmologists to take an active role in early detection and outbreak prevention.

Measles resurgence in US

• ▪Approximately 94% of the 2,777 confirmed U.S. measles cases reported in August 2026 occurred among unvaccinated individuals.
• ▪Three measles-related deaths occurred in the United States in 2025, marking the first U.S. deaths from the disease since 1991.
• ▪The U.S. Centers for Disease Control and Prevention reported 2,777 confirmed measles cases on August 20, 2026, surpassing the previous year's total of 2,289 cases.
• ▪The Pennsylvania Department of Health reported two measles-related deaths in August 2026 and two in September 2026, all occurring in unvaccinated individuals.

Declining vaccination rates

• ▪National measles immunization coverage among U.S. kindergartners declined from 95.2% during the 2019-2020 school year to 92.5% in the 2024-2025 school year.
• ▪The World Health Organization and the U.S. Centers for Disease Control and Prevention state that overall immunity must be at least 95% to achieve herd immunity and prevent measles outbreaks.
• ▪An increasing number of parents are opting their children out of required school-entry vaccinations for nonmedical reasons, while school quarantines have faced backlash following COVID-19 restrictions.

Vaccine misinformation spread

• ▪The original 1998 claim linking the measles vaccine to autism was retracted due to falsified data, and subsequent studies involving millions of children have shown no evidence of neurological or autism-related problems.
• ▪Misleading claims have promoted vitamin A as a preventative substitute for measles vaccination, prompting the American Academy of Pediatrics and the CDC to issue alerts regarding the toxicity risks of high-dose vitamin A.

Geographic outbreak distribution

• ▪A Texas measles outbreak totaling 803 cases in 2025 began in a Mennonite community in Gaines County before spreading to surrounding West Texas counties.
• ▪Utah reported 704 laboratory-confirmed measles cases since the beginning of 2026 as of July 7, 2026, including 12 cases in pregnant women and 56 hospitalizations.
• ▪A South Carolina measles outbreak totaled nearly 1,000 cases between October 2025 and March 2026, with the majority of cases concentrated in Spartanburg County.

Ocular complications from measles

• ▪The American Academy of Pediatrics recommends two oral doses of vitamin A 24 hours apart for all children with measles, but studies show only about 30% of hospitalized children receive it.
• ▪Measles can cause ocular complications ranging from mild conjunctivitis to severe keratitis with corneal scarring, ulcers, retinopathy, and optic neuritis.
• ▪Measles infection depletes vitamin A stores, and concurrent vitamin A deficiency can compromise corneal structural integrity and rapidly lead to permanent blindness.

Ophthalmologist outbreak detection

• ▪Ophthalmology clinics must isolate suspected measles patients in private rooms, require N95 masks, leave exam rooms vacant for 2 hours, and notify exposed waiting room patients.
• ▪The American Academy of Ophthalmology issued a public advisory in February 2025 and a formal clinical statement in May 2026 to guide ophthalmologists on measles diagnosis, treatment, and prevention.
• ▪Ophthalmologists can identify potential measles cases early because conjunctivitis is one of the 'triple C' early markers of the disease, appearing 2 to 4 days before the rash alongside cough and coryza.

Debatable claims

• ▪Schools should enforce quarantines during measles outbreaks
• ▪States should eliminate nonmedical exemptions for school-entry vaccinations