After her son was diagnosed with autism, Jenny McCarthy became a vocal advocate of alternative methods for treating the developmental disorder, as well as petitioning against the use of vaccines on children.

Her activism led to a public conflict when actress Amanda Peet referred to parents who refuse to vaccinate their kids as "parasites", attempting to debunk "myths" of vaccinations with the Every Child By Two organization. McCarthy has rebuked Peet by saying “I look at (Peet) now and say to myself, 'That was me before I had autism in my life,’ and until she walks in our shoes, she really has no idea."