Vaccine skepticism is proving infectious. As refusing a COVID-19 shot becomes a badge of honor for some, lawmakers are beginning to revisit existing vaccine mandates, with politicians from Florida to Montana questioning long accepted immunization requirements against diseases like polio and measles. Coupled with a precipitous drop in childhood vaccination rates during the pandemic—which first plummeted as locked-down kids skipped healthcare visits, according to the Centers for Disease Control and Prevention (CDC)—vaccine skepticism could allow previously well-managed viruses and diseases to start reappearing.