US experiencing largest measles outbreak since 2000 – 5 essential reads on the risks, what to do and what’s coming next

Measles is one of the most contagious diseases in the world. The measles outbreak in South Carolina reached 876 cases on Feb. 3, 2026. That number surpasses the 2025 outbreak in Texas and hits the unfortunate milestone of being the largest outbreak in the U.S. since 2000, when the disease was declared eliminated here. The outbreak is exposing the breadth of dangers the disease can pose. South Carolina’s state epidemiologist revealed on Feb. 4 that cases of brain swelling, a rare complication of the disease, had emerged in some infected children. Some signs suggest that this particular outbreak may be starting to wane. But many public health scholars worry that the resurgence of measles across the U.S. and worldwide, driven by a drop in vaccination rates, may signal a coming wave of other vaccine-preventable diseases. Measles is one of the most contagious human diseases on the planet – much more contagious than more familiar infectious illnesses such as flu, COVID-19 and chickenpox. At least 800 of the reported cases in South Carolina occurred in people who weren’t vaccinated. Beyond immediate symptoms, measles can cause long-term consequences including subacute sclerosing panencephalitis (SSPE), a fatal brain condition that can emerge years after infection. The U.S. is predicted to lose its measles elimination status in 2026, following the U.K. and Canada, due to declining vaccination rates and public trust.