So what do you suggest?
We abandon vaccines altogether? To the best of my knowledge all medical proceedures have a risk of side effects, and at the end of the day, if the benefit far outweighs the risk.
If there is no possible way to know something, there is no reason they should be held responsible for their actions. I'm no lawyer, but to the best of my knowledge, the liability of a company depends on them exercising sound judgment.
I would much rather have doctors decided which vaccines I need to take than, well any politician, parent, or myself.
Imagine the public outrage if a company developed a vaccination against AIDS/HIV, but found out that 0.00001% of those who take the vaccine developed a deadly side effect - and as such they decided to hold it back.
We can't have it both ways - the human body and nature is filled with ambiguity, and unless we offer protection to side effects which had no reasonable way of determining, the incentive to release a vaccine or treatment would be next to nothing.