Oklahoma State Department of Health reports 15 cases of Measles, including in vaccinated person

The Oklahoma State Department of Health has updated it's Measles case count to 15, with one reported case in a vaccinated person.

As of Tuesday, 12 cases are confirmed and 3 are ruled probable.

A probable case means a person is showing symptoms while waiting for a test confirmation.

In the latest update from OSDH, the department says it reported its first Measles case in a vaccinated person in 2025.

"It takes the body about 14 days after vaccination to develop immunity to measles, so people aren’t considered vaccinated until that 14-day period has passed," OSDH said. "The vaccine must be given at least 35 days before symptom onset to account for the 21-day incubation and 14-day period required to develop immunity post-vaccine."

To view the department's update on Measles, click here.