It doesn't do anything to your RNA, that's not how it works. If you have the instruction manual for how to build a car, and I add a new page for how to put a rear spoiler on it, the instructions don't become how to build an airplane. The instruction manual is your DNA, the new page is Pfizer's RNA. The danger from this vaccine comes from how the body will react to the new protein produced by the new RNA. They want to create an immune response to the new protein, but there is the possibility that the response gets out of control, resulting in dangerous inflammation all over your body, worst case scenario in your brain. This vaccine simply has not been tested long enough or widely enough to prove to me that the risk of a dangerous immune response is negligible.