A fast-moving measles outbreak in South Carolina reached a grim milestone recently: It is now the biggest outbreak in the U.S. in a quarter century.

It’s the latest public health record to be broken as vaccine hesitancy and increasingly permissive state laws — both now intensified by Health and Human Services Secretary Robert F. Kennedy Jr. — create more and larger pockets of disease vulnerability in the U.S.

Last year, a measles outbreak in Texas led to 762 infections and the first deaths from the disease in the U.S. in a decade. Nationwide, cases hit a 34-year high. The U.S.’s measles-free status, established in 2000, is likely to fall next — a fate that will be determined in April when a team from the Pan American Health Organization, the regional office for the World Health Organization, meets.