After an uptick in lawsuits in the 1980s, the vaccine manufacturers essentially held the government hostage and threatened to stop making vaccines unless the government took on responsibility for vaccine injury lawsuits. The National Childhood Vaccine Injury Act of 1986 was then enacted which made the taxpayers liable for injuries caused by vaccines and not the manufacturers.

This removal of liability has created the incentive to turn out new vaccines with very little testing, as the companies don't have to worry about financial hardships for injuring people, which in turn has shaped the situation that we find ourselves in today. [Full article]