Upon doing some research about vaccinations for Stewie, Lois and Peter became part of the anti-vaxxer movement on Sunday night's Family Guy. In typical, misguided, Peter fashion, he destroyed all the vaccines by blowing up the hospitals, Joker style. This resulted in an outbreak of measles in the town, and a quarantine for Quahog and its residents. Even Peter ended up getting waylaid by the disease.
Stewie decided that he wasn't going to just sit around the house and wait to get infected, so he attempted to take the bridge out of town, but ended up in a precarious situation. At the last second, actor, and, as he was quick to point out, two time Oscar winner, Sean Penn, literally flew in to save the day. He taught Lois a lesson about the importance and significance of vaccinations, even though she seemed somewhat less than thrilled to hear it.