Amanda Peet talked on Access Hollywood about her pro-vaccination stance. Credit: C Flanigan/Getty Images

Peet's pro! Amanda Peet has not been shy about advocating for parents to vaccinate their children. The mother of three, 43, recently appeared on Access Hollywood to talk about her activism and why the topic is especially close to her heart. 

"I think I'm just a concerned mom, and now that I have a newborn who's too young to be vaccinated, it really hit home for me," the actress, who welcomed son Henry in December, said of the ongoing controversy surrounding vaccinations. "I think we've just kind of lost our sense of neighborliness. Even if it's not your child, your neighbor could have an infant at home or somebody whose immunity is compromised. Shouldn't we all be in this together?"

Many parents have been up in arms due to the recent outbreak of measles, which they feel is a direct result of those not willing to vaccinate their children. 

"It's really scary," Peet said. "What's it going to take before we all get in this together? Are we going to see infant mortality rates? Because that would be infuriating and so tragic."

The Togetherness star works with the pro-vaccination organization Every Child By Two, and said she's witnessed the opposition firsthand. 

"I got tons of hate mail because I started working for Every Child By Two a couple years ago at the height of the vaccine controversy," she continued. "It's hard to communicate science."