Maurice Hilleman's daughter provided the virus that became the lasting mumps vaccine

During the early 1960s, Merck virologist Maurice Hilleman swabbed his daughter Jeryl Lynn’s throat after she developed swollen cheeks from mumps. He brought the sample to his lab and weakened the virus by growing it in successive generations of chicken embryo cells, producing a strain that lost its ability to cause illness in humans while still provoking immunity. This Jeryl Lynn strain passed human safety tests, leading to its approval by the FDA in 1967 and its incorporation into the national immunization program.

Hilleman's younger daughter, Kirsten Jeanne, received the investigational vaccine in 1966, illustrating the family’s direct involvement. The original virus seed stock, stored in stainless-steel canisters, has been preserved and transferred to newer containers to maintain potency for billions of doses. The vaccine remains a cornerstone of mumps prevention in the United States.