Measles cases in the U.S. are at their highest in more than three decades. The U.S. Centers for Disease Control and Prevention says the U.S. has 1,288 cases since the beginning of the year.

Measles cases in the United States have reached their highest number in more than 30 years, according to new federal data published Wednesday.

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.