The country’s largest measles outbreak is happening in Central Ohio — with no signs of slowing down.

• Of the 117 nationwide cases reported as of Dec. 22, 70% were in Franklin County.

Why it matters: Until this outbreak, our area hadn’t confirmed a measles case in 20 years.

• The highly contagious respiratory disease was declared eliminated in the U.S. in 2000, but dipping vaccine rates during the pandemic have revived it among unvaccinated pockets.

Threat level: The CDC and WHO said last month that measles is “an imminent threat in every region of the world,” Axios’ Jacob Knuston reports.

• Symptoms include a high fever, cough, runny nose and watery eyes, with a signature rash appearing three to five days later.
• Serious complications such as pneumonia and encephalitis are possible.

By the numbers: Of the 82 local cases confirmed as of Thursday, none were fully vaccinated and 39% were hospitalized.

• All are kids younger than 18.
• 28% are under 1 year old, meaning they’re too young to be vaccinated and were relying on herd immunity for protection.

State of play: Measles likely arrived in Columbus after four unvaccinated travelers separately went to measles-endemic countries from June to October, Columbus Public Health commissioner Mysheika Roberts tells Axios.

• The CDC was here for the two weeks after Thanksgiving and is offering support.

Of note: The two-dose measles vaccine is 97% effective.