The measles outbreak is continuing to spread in the United States with over 110 cases present in at least 16 states. 

Some parents who refuse to get their kids vaccinated have come up with another plan: hosting measles parties.

This morning on "Fox and Friends," Elisabeth Hasselbeck said that parents are bringing their kids who haven't been vaccinated around those who are infected in order to "build up their immunity."

Dr. Philippa Cheetham explained that the idea of measles parties came from chicken pox parties that began in the 1980s. She said that parents at that time wanted "to mix children who had chicken pox, with children who did not have chicken pox to try and increase exposure as a way of building up natural immunity." 

"Unfortunately, we are seeing a resurgence of this with measles, because parents are very concerned with the risks of vaccination," Cheetham noted. "Particularly this link with autism, which is being completely discredited. We must emphasize that vaccination is safe and effective." 

Watch the video above.

UPDATE: California health officials have cautioned parents not to host so-called measles parties.

The L.A. Times reported:

Marin County Public Health Officer Matt Willis said that although his office has received no reports of such parties, officials have fielded several calls from parents asking about the benefits of "natural immunity," or the idea that immunity gained from contracting a disease is superior to immunity conferred through vaccination. That concept is ill-advised and dangerous, he said.

Measles is a serious illness that can cause brain swelling, long-term neurological effects and even death, Willis said. Plus, he added, there is no evidence that immunity gained through becoming sick with measles is any better than vaccine-imparted immunity.

"Any parents who are considering this, they should have a look at a child who’s really sick with measles, and I think they’d change their minds."