lizations, although doctors say the actual number of illnesses is likely much higher. The outbreak's epicenter remains in Lancaster County, but is spreading across the state.

The Pennsylvania Department of Health did not immediately respond to a request for comment on the CDC aid.

The CDC team has previously sent teams to other states with large clusters of measles illnesses: Kansas, New Mexico, South Carolina, Texas, Virginia and Wisconsin. Such deployments are usually short -term, about one to three weeks. They're meant to help mobilize and streamline outbreak containment efforts.

In addition to the deployment, the CDC is releasing nearly $4 million to aid the measles response efforts in Pennsylvania.