While measles symptoms typically resolve in a few weeks, the virus can cause pneumonia, making it difficult for patients, especially children, to get oxygen into their lungs. It may also lead to brain swelling, which can cause lasting damage, including blindness, deafness and intellectual disabilities.

The number of measles cases in the United States has surpassed 2019's wave of infections, according to Centers for Disease Control and Prevention data.

The U.S. has hit an unwelcome milestone in measles cases this year. The CDC is reporting 1,288 cases across the country. The disease was declared eliminated 25 years ago.