Health Secretary Robert F. Kennedy Jr. has sparked controversy by posting anti-vaccine content on social media following the deaths of two people from measles in Pennsylvania, including a newborn. These are the first measles fatalities in the state in 35 years and the first in the U.S. in 2026, amid a nationwide surge with nearly 2,800 cases—the highest since 1991.

Kennedy used his personal X account to criticize the MMR vaccine and shared a link to a conspiracy site, also attacking Governor Josh Shapiro. He later used his official account to suggest the deaths were fabricated, citing a tweet from a local official. Critics see this as a return to his long-standing opposition to vaccines, undermining public health efforts during a serious outbreak.