In the wake of news on Tuesday that two people in Pennsylvania died from measles, Health Secretary Robert F. Kennedy Jr. has been posting a slew of anti-vaccine rhetoric and misinformation on social media—marking a resurgence of his old ways as a fervent opponent of lifesaving immunizations.

The deaths are the first measles-linked fatalities in Pennsylvania in 35 years and are the first US  measles deaths reported in 2026. They occurred amid an explosive outbreak in the state that has reached nearly 400 confirmed cases, as well as an ongoing nationwide surge for the vaccine-preventable disease. The US has tallied nearly 2,800 cases so far this year, the highest total since 1991.

Pennsylvania health officials initially declined to provide details about the deaths, only reporting that they were in unvaccinated people from Lancaster County. However, news broke Wednesday that one of the deaths occurred in a newborn baby. That heart-wrenching news was swiftly entangled in the anti-vaccine misinformation Kennedy was spewing online.

On Tuesday, as news of the two deaths was breaking, Kennedy took to his personal X account to rail against the measles, mumps, and rubella (MMR) vaccine and posted a link to The HighWire, a hardline anti-vaccine and conspiracy site run by Del Bigtree, a prominent anti-vaccine propagandist and Kennedy ally.

Kennedy’s post also assailed Pennsylvania Governor Josh Shapiro, who has criticized Kennedy’s anti-vaccine rhetoric and activism. Kennedy went on to blame national declines in vaccination rates on the Biden administration.

On Wednesday, as news broke that one of the deaths in Pennsylvania was in a newborn, Kennedy turned to his official X account as US health secretary to allege that “the deaths may even have been altogether fabricated by one of the Governor’s hopeful staffers.” He cited a tweet from Josh Parsons, a Republican commissioner of Lancaster County, who claimed there had been “zero measles deaths” reported in the county. The claims appear to be another old play from the anti-vaccine handbook.