SACRAMENTO, Calif. (KABC) -- There is a new push underway to toughen California's immunization law.A state lawmaker has introduced a bill that would ban anti-vaccine parents from doctor-shopping for medical exemptions.Under California law, every child in California must receive mandatory vaccinations unless they have a medical exemption.But Sacramento Sen. Richard Pan, who is a doctor, said the number of unvaccinated children in California is spiking.He blames crooked doctors.Senate Bill 276 would prohibit doctors from giving vaccine exemptions .Instead, parents who want to petition to let their children attend school without vaccines would have to ask the California Department of Public Health.