Two unvaccinated individuals have died from measles in Pennsylvania, the state Department of Health announced Tuesday. These are the first measles-related deaths in the state in 35 years and the first reported in the U.S. this year.

"My deepest sympathies are with the loved ones who are facing this unimaginable loss," said Dr. Debra Bogen, Pennsylvania's Secretary of Health. "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."

The Centers for Disease Control and Prevention (CDC) recommends two doses of the measles, mumps, and rubella (MMR) vaccine. The first dose is recommended between 12 and 15 months of age, and the second between 4 and 6 years of age. According to the CDC, one dose of the MMR vaccine is 93% effective, while two doses are 97% effective.

In late July, the total number of confirmed measles cases in the U.S. surpassed the count for all of last year. Last year saw 2,289 reported cases, the highest in more than 30 years. The current year's total of 2,777 cases marks the highest number recorded since 1991.