Photo: Jessica Biel/Instagram

Jessica Biel

There is no scientific link between vaccines and autism, according to the Centers for Disease Control.

On Tuesday, Kennedy Jr., 65,shared a slideshow of photosof himself and Biel, 37, posing alongside activists and legislators.

“Please say thank you to the courageous @jessicabiel for a busy and productive day at the California State House,” Kennedy Jr. wrote of the actress, who is married to singerJustin Timberlake, 38. The couple share 4-year-old sonSilas Randall.

Biel and Kennedy Jr. lobbied againstSB 276, a California state bill that would limit medical exemptions from vaccinations without approval from a state public health officer.

Jessica Biel.

Jessica Biel

The bill would require “the State Public Health Officer or the public health’s officer’s designee to approve or deny a medical exemption request, upon determining that the request provides sufficient medical evidence that the immunization is contraindicated or that a specific precaution regarding a particular immunization exists, based on guidelines of the federal Centers for Disease Control and Prevention (CDC),” the bill states.

When asked to describe Biel’s involvement, Kennedy Jr. explained toThe Daily Beastthe actress is “for safe vaccines and for medical freedom.”

“She has friends who have been vaccine-injured who would be forced to leave the state,” he claimed.

Jessica Biel

Jessica Biel and Robert F. Kennedy Jr.

Jessica Biel

Multiple large studies have confirmed that vaccines are safe and do not cause autism, but anti-vaxxers and religious groups have rallied against vaccinesas misinformation spreads online. Over the last year, there has been a30 percent increase in measles cases worldwideanddeadly outbreaksin areas with large amounts of unvaccinated children. In the U.S.,the number of measles cases in 2019is now up to 1,022, as of June 6, the most in over 25 years. Though measles was considered eradicated in 2000 with the advent of the measles vaccine, the U.S. may lose that status if the outbreak continues.

In January, the World Health Organization namedvaccine hesitancy— the “reluctance or refusal to vaccinate despite the availability” — asone of the top threats to global health in 2019.

Kennedy Jr. has been a controversial figure in the anti-vaxxer movement after making claims that vaccines can cause autism, ADHD, ADD and speech delay,The Daily Beastreported in February.

In 2015, a source toldInTouch Weeklythat Biel “feels that vaccination could cause complications.” However, she has never publicly stated her position on vaccinating children against diseases.

A representative for Biel did not respond to PEOPLE’s request for comment.

source: people.com