Most of the doctors in this book have a MD or higher (allopathic) education and some are natural practitioner doctors. Many have qualifications from both sides of medicine.
Not all doctors agree that vaccines are safe and effective and this book only includes a small selection of doctors that have gone public with their opinion.
Sure there is a benefit to keeping quiet about this 600lb gorilla in the room of modern medicine, but is money going to keep you warm when your family finds out that you were warned by other doctors and kept injecting little babies with known toxins anyway?
While doctors can't say they are 'against' vaccines outright without backlash, all the doctors in this book have publicly challenged the dogma of vaccination in attempts to reveal the real risks to others. Often these doctors are professionally castigated and they lose everything; careers, partners, houses and sometimes their very life.
These doctors are doing the morally correct thing by informing us of the dangers of vaccines in a medical world drowning in pharmaceutical vaccine money. These doctors used their brain when fronted with the evidence that vaccinations cause harm. They followed the evidence trail and those crumbs are fat and glaringly obvious for those with eyes to see.