Anti-vaxxer parents living in tony communities like Santa Monica and Beverly Hills are rejecting vaccinations for their children resulting in a disturbing spike in diseases such as whooping cough and measles.

Parents are filling out vaccination exemption forms called a “personal belief exemption,” (PBE) which allows children to forgo important vaccinations. The Atlantic reported that in some schools up to 70 percent of parents have filed these PBEs, reflecting a vaccination rate as low as that of Chad or South Sudan.

Where in the South Sudan parents have trouble getting their children vaccinated because of an ongoing civil war, in Santa Monica and Beverly Hills parents are voluntarily rejecting the vaccines following alternative lifestyle guidelines propagated by the rich and famous such as Westside vaccine decliner Alanis Morissette and Jenny McCarthy.

Many parents are driven by the concept that they want only natural things for their children and avoid medications that aren’t strictly natural, reports Gary Baum in the Hollywood reporter. Yet, Baum points out that , vaccines are natural–they’re derived from the naturally-occurring pathogen itself.

The Hollywood Reporter investigation found that wealthy Westside kids — particularly those attending exclusive, entertainment-industry-favored child care centers, preschools and kindergartens — are far more likely to get sick (and potentially infect their siblings and playmates) than other kids in L.A.

Unfortunately, the increase in PBEs has dropped immunization level in some communities that a resurgence of diseases like whooping cough, otherwise known as pertussis has increased and measles cases have also hit a high in California this year, reported the Los Angeles Times.

According to the U.S. Centers for Disease Control, the number of domestic measles cases is at a 20-year high. About half of the cases in California involve unvaccinated patients.