Measles surge puts US schools on alert as vaccination coverage slips below key threshold

With confirmed cases at their highest level in decades and kindergarten MMR coverage below 95%, schools are being urged to check immunisation records and prepare for outbreaks.

The United States is facing its worst measles year in more than three decades, and schools are being urged to prepare as outbreaks continue to climb. The Centers for Disease Control and Prevention says confirmed cases have now surged well past last year’s total, while vaccination coverage among kindergartners has slipped below the level public health experts say is needed to keep the virus from spreading easily. In practical terms, that means school leaders are being asked to know who is protected, who is not, and how they will respond if a case appears in the building.

Measles is exceptionally contagious, and there is no antiviral medicine that treats it directly. Dr. James Campbell, interim head of paediatric infectious disease at the University of Maryland School of Medicine, told Education Week that younger children are most vulnerable to severe illness, and that even otherwise healthy pupils can end up with complications such as ear infections or hospital treatment for dehydration. William Moss, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health, said the scale of current outbreaks is unusual and resembles the national surge seen in the late 1980s and early 1990s, before school-entry vaccine rules helped drive measles to elimination in the United States in 2000.

The latest CDC figures show 4,410 confirmed cases nationwide as of Oct. 16, a sharp rise from the 2,289 recorded in all of 2025. The agency also reports that 92.4% of kindergarten pupils completed their MMR series in the last school year, down from 95.2% in 2019-20. That may sound close, but public health specialists say the difference is decisive: measles can spread rapidly unless roughly 95% of children are immune, because the virus can otherwise move through classrooms, staff rooms and households with remarkable speed. The CDC says about 280,000 kindergarten pupils did not have records showing they had completed the series.

The outbreak has hit some communities far harder than others. Pennsylvania has been the epicentre, with more than 1,000 confirmed cases and five measles-associated deaths reported by the state, while New York has declared a disaster emergency as infections continue in low-immunisation counties. In Pennsylvania, health officials say children account for roughly a third of cases, but adults make up a large share as well, underscoring that schools cannot focus only on pupils. Unvaccinated staff members can also bring the virus into classrooms or pass it on once it arrives.

That is why experts say preparation now matters more than panic later. Schools are advised to keep up-to-date records showing which students are fully vaccinated, partially vaccinated or unvaccinated, and to move quickly if exposure is reported. An unvaccinated child who receives an MMR jab within 72 hours of exposure may avoid the 21-day quarantine that otherwise follows. Campbell and Moss also urge schools to check staff records, review whether adults on site are immune, and have a clear plan for isolation, notification and coordination with health departments if a nurse suspects measles. Moss said the safest course is to isolate the child, alert public health officials and warn the hospital before the family arrives, to reduce the risk of spreading the virus in a crowded emergency room.

Some districts are already treating that level of readiness as routine. In Springfield, Ohio, school nurses keep records on which pupils are fully immunised, partially immunised or unvaccinated, allowing staff to identify exposed students quickly if a case is reported. District nurse Bronwyn Patterson said local health guidance gives exposed unvaccinated students 72 hours to get protected before exclusion rules apply. But she also noted the limits of school planning: students move through buses, corridors, sports, clubs and family networks every day, and no district can track every contact. For her, the bigger lesson is that measles control depends on community coverage, not just school procedure. “It’s not a matter of if, it’s when,” she said, “and how prepared are we.”