Two unvaccinated people have died from measles in Pennsylvania, the state health department said Tuesday.

“My deepest sympathies are with the loved ones who are facing this unimaginable loss,” Dr. Debra Bogen, the state’s secretary of health, said in a statement. “Because measles was largely eliminated in the Commonwealth for more than three decades, people are not familiar with this disease and don’t fully understand the potential severity of the illness.”

These deaths were the first measles-related deaths in Pennsylvania in 35 years.

In late July, the number of confirmed measles cases in the U.S. surpassed the total reported for all last year, according to data from the Centers for Disease Control and Prevention.

Last year’s total of 2,289 was previously the highest number of recorded measles cases in more than 30 years, CDC data shows. However, the 2,777 total now marks the highest number of cases recorded since 1991.

“We want to ensure every Pennsylvanian has the information they need to protect themselves, their loved ones and their communities,” Bogen’s statement continued. “As a physician, I want to make sure that people understand that the MMR vaccine is safe and provides the best protection we have against measles.”

The CDC currently recommends that people receive two vaccine doses, the first at ages 12 to 15 months and the second between 4 and 6 years old. One dose is 93% effective, and two doses are 97% effective.

“Vaccination remains the best defense against measles infection,” the CDC said in a statement. “Measles does not have a specific antiviral treatment. Supportive care, including vitamin A administration under the direction of a physician, may be appropriate.”