At his six-month check up, Jacob Thompson received a combination shot that included the recommended childhood vaccinations against diphtheria, tetanus and pertussis, or DTaP, all deemed safe and effective in clinical trials. Later that day, Jacob began to seize.  Doctors hoped the seizure was a one-time reaction. It wasn't. In the following months as the seizures continued, doctors diagnosed Jacob with a rare and severe form of epilepsy. His parents, John and Huali, became increasingly