It is normal to associate a bad experience to something you do not quite understand. But, let me explain as best I can. A dead virus inside the bloodstream does not cause migraines. A vaccination is the injection of a saline solution - part water with a little salt in it to match the salt content of your blood - and the physical body of a virus that had been grown in the lab, then killed, then put into the solution, then injected into your blood stream. A dead virus does not live, nor does it magically come back to life. Your body CAN react to it, such as an allergic reaction to it, but that shows in the form of high temperatures and flu-like symptoms, or skin rashes as the body tries to get rid of the body of the virus. Seizures are the brain having electrical issues, much like too much electrical overload at once. Migraines are commonly started with blood not flowing through the brain fully because of a blood artery through the neck being pinched, or in your spinal cord, a blood artery in your backbone or spinal cord is being pinched. The numbness in your hands and feet is a strong indication you have had a pinched artery that decreased or diminished blood flow to your hands or feet, and then to your head later on, causing the migraine when your brain had not enough blood flow in it. The sources are usually a pinched blood artery in one of your backbones, usually where the neckbones intersect at the shoulders. I have a large bosom, and the strain of carrying their weight causes my shoulders to hunch and can pinch my artery to my hands, feet and brain, and I get numbness in my hands and feet and migraines if I sleep on my back wrong. Migraines can also be caused by a neck strain, perhaps from a sports injury, being in a minor car accident such as a "fender-kisser" where someone hit your car from behind, or even a bad dive into a swimming pool when learning to swim. Now, your sister having skin issues would have surely been a an allergic reaction to the foreign object, however small, inside her body. However, some 15 years later, you and her have been exposed to billions of bacteria and viruses, but also, your body cells and blood have recycled and replicated and filtered out your blood completely about 3 times, so the dead virus may not be to blame all by itself, your sister may have developed allergies due to genetic factors. You probably do not know the full medical history of your family. It may be that she is not the only one who has skin allergies to certain allergens in your family, you just don't know enough about your family's medical history to know. It would be wise for both of you to take a blood allergy test to find out for sure what is causing these symptoms. As for your seizures, it has been found that seizures and epilepsy are connected to genetic sources, such as an an inability to process proteins, low blood sugar, or, if you have regular migraines, a cut off of blood flow to your brain. One virus in a vaccine may not have been the cause of this, you simply associate body pain and suffering to something you don't understand because of medical information about your own body you do not know. The best thing to do would be to make an appointment with your doctor, explain your history of migraines, ask for a blood test to find out your allergies you may have been unaware of, and then work with your doctor to learn how to eliminate allergens, find a mattress and pillow to improve your sleep, and body exercises to put blood flow back into your brain. The real goal is overall health, but it is best not to self-diagnose and self medicate. It is better to ask a health professional for the real cause, and then set up a health maintenance program to work on to overcome towards better health. Do make a doctor's appointment and good luck.