On Tuesday, Robert F. Kennedy Jr., an environmental activist and vaccine skeptic, took to Instagram to reveal that he and the 37-year-old actress teamed up to speak out against a proposed California bill that would limit medical exemptions from vaccinations without approval from a state public health officer.

"Please say thank you to the courageous @jessicabiel for a busy and productive day at the California State House," Kennedy wrote alongside pics of him and Biel speaking to people and participating in meetings.

Following Kennedy's post, speculation surrounding Biel's vaccine stance quickly circulated. But, on Wednesday morning, the actress took to Instagram to clarify her beliefs.