Though still a small minority, a growing number of California parents are choosing not to vaccinate their children, fearing what they believe are dangerous side effects. 

The phenomenon is frustrating public health experts, who believe the anti-vaccination movement is in part responsible for the reemergence of diseases like measles and whooping cough. 

It's an issue Southern California Public Radio's Rebecca Plevin has been looking into and she shares more. 

Related: More California parents opting out of vaccinating their kids