Snopes confirms that Kennedy’s assertion linking fetal tissue to the MMR vaccine is incorrect, as misinformation fuels vaccine hesitancy during a significant measles outbreak in the US.
Robert F. Kennedy Jr.’s claim that the MMR vaccine contains fetal tissue is false, according to Snopes, which said the health secretary repeated a long-running falsehood in August 2026 while answering criticism from Pennsylvania Governor Josh Shapiro. The fact-checking site said Kennedy pointed to the rubella component of the shot and cited the WI-38 cell line, but that does not mean the finished vaccine contains material from an abortion.
The rubella strain used in the vaccine was developed in cells originally taken from lung tissue from a legally aborted three-month-old female embryo in Sweden in the early 1960s. But, as Snopes and the University of Nebraska Medical Centre explained, those cells are used as a growth medium during production and are removed during purification, leaving no fetal tissue in the final product. FactCheck.org has made the same point in earlier vaccine fact checks, noting that cell lines derived decades ago are not the same thing as fetal tissue in a vial.
The claim matters because measles has surged again. The Centres for Disease Control and Prevention said the United States was experiencing its worst measles outbreak since 1991, with 2,777 cases reported from the start of 2026 through August 20 and three deaths recorded in 2025. Harvard Medical School has said measles typically requires about 95% immunisation coverage to prevent spread, but coverage has slipped in recent years, including in parts of West Texas where the outbreak began.
Health experts say misinformation has been a major driver of vaccine fear, and Kennedy has repeatedly amplified such claims. The Guardian reported in 2025 that his comments about “aborted fetus debris” in the MMR vaccine alarmed public health experts, who warned that misleading statements can further weaken confidence in immunisation programmes. The MMR shot remains a two-dose vaccine, and Harvard Medical School said most people infected in the current outbreak were unvaccinated, of unknown vaccination status or had received only one dose.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
