There's new information on the recent measles outbreak.
Infections are spreading, with 68 cases of measles in seven states and Mexico.
Forty-eight of those cases are linked to Disneyland in southern California.
The Centers for Disease Control and Prevention says there were more than 600 cases of measles reported last year, a record high.
It's skyrocketed because there are parents who refuse to vaccinate their children.
Elizabeth Cohen reports.
"Parents need to know what is being injected into their child," says actress Jenny McCarthy, mother of an autistic child.
Call it the "Jenny effect."
"Without a doubt in my mind, I believe vaccinations, vaccinations triggered Evan's autism," McCarthy says.
Almost a decade ago, actress Jenny McCarthy became the spokeswoman for the anti-vaccination movement, a movement that's only grown stronger, finding support among well-educated communities, despite since science showing over and over there's no link between autism and vaccines.
In California, for example, a study out this week shows low rates of vaccination in San Francisco and Marin County, both wealthy areas.
In southern California, affluent areas in Los Angeles have had immunization rates that rival South Sudan's.
"When parents choose to not vaccinate, other parents around them may have similar ideas. So what you get are pockets, groups of people who think the same," says Dr. William Schaffner, an infectious disease expert. "And so now you have a cluster of children who are susceptible, all kind of living and playing together going to similar schools, houses of worship and the like, so if that bad germ gets into the group, then woosh, all of the sudden you'll have an epidemic."
So why don't parents believe the scientists?
Some of them are convinced the government is working with the pharmaceutical industry and just wants to sell the vaccines.
I'm more willing to take the chance of her getting one these rare viruses or diseases, or give the side effects of these vaccines, which a lot of times is autism"
"I do not see that there is ever an acceptable time to inject a known toxic, a known poison, a heavy metal into the body of a 6 pound and up child to help save their life, through a vaccine. No poison is safe. No poison can be given to a child and it's ok."
The supposed link between autism and vaccines was championed by British scientist Andrew Wakefield.
But his paper was discredited and redacted from the British Medical Journal in 2011.
"The study is not a lie," Wakefield says. "The findings that we made have been replicated in five countries around the world."
"Sir, that's not true," says CNN host Anderson Cooper. "You have, you have been offered the chance to replicate your study, and you have never taken, taken anybody up on that. You have had plenty of opportunity to replicate your study."
"Just accused me of giving you a falsehood," Wakefield replied. "I'm telling you that this work has been replicated in five countries around the world."
That was not true, but even so, many parents still believe Wakefield was right, still believe the government is lying to Americans, and still refuse to vaccinate their children no matter what.