It was once thought to be wiped out — but measles, the world’s most contagious disease, is back with a vengeance.

Eight new cases in South Carolina this week have pushed the state’s total to 33, putting health officials on red alert. Mobile vaccination units are racing across communities, offering free MMR shots to stop the spread before it reaches millions more. “We’re seeing numbers we haven’t seen in over 30 years,” one doctor warned.

Nationwide, over 1,600 cases have been confirmed this year — most in children and teens who were never vaccinated. The last time America saw an outbreak this large was in 1992. Experts say the virus spreads faster than almost any other disease: one infected person can pass it to 18 others.

Once nearly eradicated, measles has resurged as vaccination rates have slipped below the safe 95% mark — a result of rising skepticism and pandemic disruptions. Doctors call it a “heartbreaking setback” for modern medicine.

Symptoms start like a common cold — fever, cough, runny nose — before erupting into a rash that can be deadly for the young and vulnerable.

As one health expert put it: “We beat this once. We can do it again — but only if we choose science over fear.”