Pennsylvania confirmed two deaths related to measles on Tuesday, marking the first such losses in the Commonwealth of Pennsylvania in 35 years. Both individuals were from Lancaster County and were unvaccinated, according to the Pennsylvania Department of Health.

The deaths come as measles cases rise across the state. The department has confirmed 393 cases in 28 counties so far in 2026.

Health officials described vaccination as the best way to prevent measles infection. The measles, mumps and rubella vaccine, known as the MMR vaccine, is administered in two doses and can provide 97% lifetime protection, according to officials.

Pennsylvania Secretary of Health Dr. Debra Bogen shared her "deepest sympathies" with the "loved ones who are facing this unimaginable loss." She also warned that many people may not recognize the potential severity of measles because the disease was largely eliminated in the state for more than three decades.

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"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," Bogen said in a statement. "We want to ensure that every Pennsylvanian has the information they need to protect themselves, their loved ones and their communities."

Bogen also emphasized the protection offered by vaccination. "As a physician, I want to make sure that people understand the MMR vaccine is safe and provides the best protection we have against measles."

Measles is a highly contagious virus that can be fatal in one to three patients per 1,000 cases, according to data cited in the report. Nearly 20% of people who contract measles are hospitalized, while the virus can also cause pneumonia and brain swelling.

The virus spreads when an infected person breathes, coughs or sneezes, releasing respiratory droplets. It can remain infectious in the air and on surfaces for as long as two hours after the infected person has left the area.

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Early symptoms include fever, cough, a runny nose and red, watery eyes. A rash generally appears a few days later, beginning on the head before spreading down across the rest of the body.

Symptoms may begin seven to 21 days after exposure. People who believe they have been exposed should contact a healthcare provider, according to the report.

Dr. Jesse Goodman, a former FDA chief scientist in Washington, D.C., called the MMR vaccine "extremely safe and highly effective." He said it has prevented measles deaths around the world and rejected claims connecting the vaccine to chronic illness.

"The vaccine prevents millions of measles deaths worldwide annually, including hundreds that used to occur in the U.S.," Goodman told Fox News Digital. "There is no evidence that MMR vaccine causes any chronic illnesses, including autism."

Dr. Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security in Baltimore, Maryland, said Pennsylvania's 35 year period without a measles death "wasn't luck." He credited vaccination with protecting a generation of families from seeing the damage the virus can cause to a child's lungs or brain.

Dr. Marc Siegel, Fox News senior medical analyst, also stressed the highly contagious nature of measles amid elevated case counts across the United States. "Measles is so contagious that up to 90% of susceptible people who are exposed to an infected person will become infected," he told Fox News Digital.

Siegel said a 95% vaccine coverage rate is needed to ensure herd immunity. He described that threshold as a mathematical estimate based on how contagious a disease is and how effectively immunity from vaccination or a prior infection prevents transmission.

According to Siegel, vaccination with two doses is almost 100% effective, while natural immunity after measles infection is generally lifelong. He said community protection is particularly important for people who cannot receive a live virus vaccine because they are immunocompromised or pregnant.