( CNN ) -- The re-emergence of some vaccine-preventable diseases has prompted the California legislature to consider a bill that would make it more difficult for parents to opt out of vaccinating their kids . The legislation would require that parents get counseling from a doctor before opting out of immunizations for their children . Last year , the United States saw its highest number of reported measles cases in 15 years , even though the disease was eliminated from the country in 2000 , according to the Centers for Disease Control and Prevention . One theory behind this rise , according to Dr. Richard Pan , the state assemblyman who introduced the bill , is that the recent trend away from immunizing children . That 's why he wants to make it more difficult to bypass vaccine requirements in his state . Jillian Edwards , a 27-year-old mother of two , is one of a number of parents who are not at all , or only partially , immunizing their kids . `` In the first year of their life , the kids get like 15 shots , which is so much for such a tiny body , '' Edwards said . `` I think it was more the likelihood of them catching the disease versus the likelihood of them having a bad reaction . '' Dr. Steven Nishibayashi says that 's a common sentiment among many parents when it comes time to immunize their kids -- even though it 's not backed by science . `` Most of the fears about immunizations are not well founded , '' he said . Nishibayashi has been a pediatrician for 32 years . He said one of the most damaging works ever published about vaccines was a 1998 article in the medical journal The Lancet . It was written by the now-infamous Dr. Andrew Wakefield , who argued that there was a link between the measles , mumps and rubella vaccines , and autism . Nishibayashi said , however , that no one knows what causes autism . Even with people refusing vaccines , or delaying them , or spacing them out , autism rates continue to rise , he said . Some scientists say that this is simply a function of more awareness , better diagnosis and a broadening of the definition of what constitutes the disorder . The Lancet retracted the Wakefield article in 2004 and Wakefield lost his medical license ( Wakefield is now suing the British Medical Journal and one of its authors for defamation ) . But the damage had already been done . Many doctors believe parents ' fears about vaccines -- brought on by the Wakefield article and other non-scientific information -- has lead to a resurgence of diseases like measles and Pertussis or Whooping Cough . In 2010 , 10 children died in from Whooping Cough in California . The outbreak lead to a requirement that at age 10 , before entering the seventh grade , kids must have a Pertussis booster shot . Nishibayashi said the result was that the following year there were no deaths from Pertussis . The World Health Organization is hopeful that legislation like the bill in California will turn the tide of parents opting out of vaccinations . The anti-vaccine movement is not helping the fight against measles in Europe . There were 37,000 cases of measles reported last year in all of Europe , compared to 222 cases in the United States . `` I would say that you have a very active , if not the most active , anti-vaccination lobby globally in the U.S. , '' said Robb Butler with the WHO . `` That certainly does n't help , if I can be completely honest and open about this . '' Nishibayashi said there is plenty of good and accurate science that shows there is no definitive link between vaccines and other problems like autism . The problem , said Nishibayashi , is that because vaccines are generally administered around the time that autism is first diagnosed in children -- the first two years of life -- there is no way to prove to an absolute statistical certainty that the two are n't related . `` That 's where all this sort of quackery comes about , '' said Nishibayashi . The bill in the California legislature requiring medical counseling has passed the assembly and is headed for the Senate . Pan , author of the bill , says it looks like it will come up for a full Senate vote , and may pass before school resumes in the fall .
Bill would require counseling before parents can opt out of vaccinations for kids . Comment: World Health Organization expert says U.S. has one of the largest anti-vaccination voices .