Two people who were not vaccinated against measles have died of the virus in Pennsylvania, health officials said.

The state has seen 393 cases of the highly contagious virus this year, as infections across the US have hit the highest point in 35 years.

Eighty-five percent of kindergarten-age students in Lancaster County, where the recent deaths occurred, are vaccinated against measles - well below the 95% rate needed for herd immunity to limit the spread and protect immunocompromised people.

Last year, two unvaccinated children in Texas died from a measles outbreak that infected over 1,000 people, primarily children.

"This is a serious and a growing problem across our country and in our commonwealth," Pennsylvania Governor Josh Shapiro said in a news conference on Tuesday. "This illness and death from measles is completely preventable."

He added that the mumps, measles and rubella (MMR) vaccine was the best tool to protect against illness and death.

Officials said they would not share any additional information on the identities of those who died, including if they were children, who have face a higher risk of death and complications from measles.

The US has seen 2,777 confirmed cases of measles in 2026, just seven months into the year, up from last year's high of 2,289.

The rising number of cases comes as vaccine hesitancy in the US has increased in recent years, leading to lower immunisation rates. The US recommends two shots to children between ages one and six, which is 97% effective in protecting against the illness.

Earlier this month, President Donald Trump signed an executive order that calls for fewer childhood vaccinations and recommends splitting the MMR vaccine into three separate shots. Public health experts worry the order will cause confusion about an already safe and effective vaccine and prove costly.

The executive order came after Health Secretary Robert F Kennedy Jr took a number of steps to remake US vaccine policies over the past year, including the childhood vaccination schedule. Many of the changes were blocked by a federal judge earlier this year.

A vaccine skeptic, Kennedy has shared mixed messaging on the MMR vaccine, at times endorsing it and other times sharing unproven claims about its safety.

Speaking on Tuesday, Shapiro said he spoke with Kennedy over the phone that morning and that he had offered to send staff from the US Centers for Disease Control and Prevention (CDC). Shapiro said he was "very blunt" with Kennedy about vaccinations.

"I made very clear that his actions and the rhetoric that's coming from this administration are having a negative impact on communities across America... that there's real life consequences to spreading misinformation," Shapiro said.

The US is on track to lose its status of having eliminated measles, which will be determined by a panel in November. Canada lost its status last year.