At the moment, the Facilities for Illness Management and Prevention (CDC) confirmed 172 new measles circumstances for 2026, growing a skyrocketing outbreak to 588 infections up to now. And the most important outbreak within the nation, in South Carolina, which began in October, has grown by 58 circumstances in three days, reaching 847 circumstances.
Final 12 months, the CDC confirmed 2,267 circumstances, essentially the most since 1991. Projecting 588 circumstances a month for 2026 would imply greater than 7,000 whole circumstances, although the speed of sicknesses might ebb and stream because the 12 months progresses. Final 12 months, the nation topped 600 measles circumstances in early April.
The massive inflow is occurring at a time when a high CDC official expressed little concern that america is on monitor to lose the measles elimination standing it gained in 2000. Final week, Ralph Abraham, MD, the CDC’s principal deputy director, stated shedding elimination standing is the “price of doing enterprise” as he emphasised “private freedom” over vaccination, regardless of the large availability of a extremely efficient vaccine.
Abraham additionally wrongly tied elimination standing to worldwide journey, even though it solely has to do with regionally acquired circumstances.
CDC reviews first outbreaks that started in 2026
After confirming 49 outbreaks in 2025, the CDC right now famous the primary two of 2026, involving eight sufferers whole. The overwhelming majority of the 588 circumstances are tied to outbreaks that began in 2025 and proceed to develop this 12 months. The CDC defines an outbreak as three or extra associated infections.
Of the 588 circumstances this 12 months, 94% (550) are outbreak-related. And solely three are travel-related. The remaining 585 regionally acquired circumstances had been reported by 17 states.
Amongst sufferers, 27% are 5 years and youthful, and 85% are in these 19 years and youthful. The p.c of measles sufferers 20 and older has dropped from 30% in 2025 to 11% up to now this 12 months. Ninety-three p.c of case-patients had been unvaccinated or have an unknown vaccine standing.
Three p.c have been hospitalized, down from 11% in 2025.
The CDC notes that the measles, mumps, and rubella (MMR) vaccine could be very protected and efficient. MMR vaccination protection amongst US kindergartners, nonetheless, has dropped from 95.2% within the 2019-20 faculty 12 months to 92.5% within the 2024-25 faculty 12 months, leaving about 286,000 US kindergartners in danger this faculty 12 months.
The variety of public publicity websites signifies that measles is circulating in the neighborhood.
In its replace right now, the South Carolina Division of Public Well being (SCDPH) reported 847 measles circumstances in its outbreak, which is centered within the Upstate area, notably in Spartanburg County. That’s 58 greater than on January 27, when the outbreak formally surpassed the 2025 West Texas outbreak as the most important within the nation. Instances have surged in latest weeks (see the SCDPH graph at left).
The well being division stated, “The vast majority of circumstances are shut contacts of recognized circumstances. Nonetheless, the variety of public publicity websites signifies that measles is circulating in the neighborhood, growing the danger of publicity and the danger of an infection for many who should not immune on account of vaccination or pure an infection.”
The SCDPH stated the most recent publicity website is a Burger King in Roebuck, situated in Spartanburg County. Of the 847 circumstances, 813 (96%) have been in Spartanburg County.
As well as, Idaho now has 21 measles circumstances in 2025 and 2026, with seven of them in 2026, per an replace from the Idaho Division of Public Well being this week.
Report spotlights travel-related transmission
Colorado scientists emphasize getting the MMR vaccine after detailing an 11-case measles outbreak late final spring tied to a world traveler. The report additionally paperwork how readily the illness spreads on an airplane.
Reporting within the CDC’s Morbidity and Mortality Weekly Report, the researchers—from the CDC and Colorado state and native public well being departments—describe how a traveler who contracted measles in america traveled internationally, then returned to the nation whereas nonetheless contagious, immediately infecting no less than 9 different folks.
4 of the 11 sufferers had been hospitalized.
The CDC notified Colorado state well being officers on Could 20, 2025, of a measles case involving an unvaccinated, non-Colorado resident who had arrived in Denver, Colorado, on a world flight and traveled via Denver Worldwide Airport whereas infectious. The individual—the index affected person—had measles signs on the return journey to Denver.
Officers confirmed 9 extra measles circumstances in Colorado, all however one involving adults. 4 of the 9 secondary case-patients in Colorado had obtained two doses of the MMR vaccine.
The primary confirmed secondary case concerned an unvaccinated younger youngster sitting greater than two rows from the index affected person. Two different circumstances concerned totally vaccinated adults seated inside two rows of the index affected person. A fourth flight-related case occurred in a vaccinated one that was seated 5 rows from the index affected person, illustrating how properly the virus travels via the air.
Two measles, mumps, and rubella (MMR) vaccine doses are 97% efficient in stopping measles.
5 extra circumstances had been tied to publicity to the index affected person at Denver Worldwide on Could 13 or 14. The report notes that “different jurisdictions” (ie, not Colorado) reported seven extra circumstances tied to this outbreak. The ultimate case was labeled as “tertiary,” which means a case arising from contact with one of many secondary case-patients.
The research authors word, “Measles is a extremely contagious vaccine-preventable illness. Two measles, mumps, and rubella (MMR) vaccine doses are 97% efficient in stopping measles.”
They add, “Throughout this investigation, testing of urine specimens enhanced case discovering, particularly amongst vaccinated individuals, who might need skilled milder signs and probably obtained a unfavorable measles IgM check outcome.” Two sufferers who obtained unfavorable polymerase chain response check outcomes from nasal swabs examined optimistic through urine sampling.