What proof is there that the swine flu vaccine is safe?

I'm just going to explain what a vaccine is. A virus's goal is to replicate itself. It does this by injecting it's DNA into a red blood cell by a small cell called a phage. The DNA changes the red blood cell, and ultimately the cell will create more of the phages carrying DNA. A vaccine is basically just the injector of the DNA (the phage), but without the DNA. This way, your body can create antibodies for the phages without getting the actual illness. Typically, there are some people who will get "sick" because their body is taking the usual reaction to having invaders in the body. However, your mother isn't really getting swine flu. If she ever does get exposed to swine flu, she will already have antibodies prepared to fight them. The only time it would hurt you is if you were given the vaccine when you were already sick, or your immune system was already compromised significantly, or if the vaccine is faulty.