Public health officials are monitoring measles transmission as U.S. students return to school for the 2026-27 academic year. The return to class coincides with data showing the highest number of measles cases in recent U.S. history and a record-high rate of vaccine exemptions among kindergarteners.
The Centers for Disease Control and Prevention (CDC) released data this week showing that nonmedical vaccine exemptions for kindergarteners reached 4.2 percent during the 2025-26 school year. Lori Freeman, CEO of the National Association of County and City Health Officials, stated that current trends suggest measles transmission will continue unless public concerns regarding immunization are addressed.
The Trump administration has recently introduced changes to federal immunization guidance. Earlier this month, President Trump signed an executive order directing that the measles, mumps, and rubella (MMR) vaccine be split into individual doses for each disease. Currently, the MMR vaccine is typically administered as a single combined shot.
Following the executive order, officials in several states, including California, New York, Virginia, and Pennsylvania, announced they would maintain existing vaccine guidance. Additionally, acting on the order is currently considered unfeasible because no manufacturers in the United States currently produce monovalent vaccines that target measles, mumps, or rubella individually.
For families, the concrete day-to-day change involves a potential shift from two combined MMR vaccine appointments to six separate appointments if the administration's order were implemented. However, because U.S. manufacturers do not currently produce these individual vaccines, parents and healthcare providers currently lack the supply to follow the new federal directive. Public health officials indicate that the immediate impact for students in areas with low coverage will be a continued risk of measles transmission within the classroom environment as the new school year begins in August.
The knock-on effects include a growing policy divide between federal and state governments. By choosing to retain preexisting guidance, states like New York and California are effectively setting independent standards that conflict with the executive order. The long-term impact on the vaccine market remains unclear, as any shift toward monovalent doses would require a significant change in U.S. manufacturing capabilities. Currently, most U.S. public schools are scheduled to have started their academic years by the end of August 2026, while the administration's efforts to rewrite long-held vaccine policies continue.
In other health developments, the Food and Drug Administration (FDA) approved a new blood test from Roche for diagnosing Alzheimer’s disease on Sunday. The Elecsys Phospho-Tau test is the fourth such diagnostic tool to receive FDA approval in less than two years. Additionally, the Florida Department of Health reported a third death from the bacteria Vibrio vulnificus as of August 15, with 17 confirmed cases across 12 counties.