this is common. Older folks do not have a great immune system. Your immune system is like a bunch of soldiers, ready to attack an intruder. IN comes the virus and they go to war. Causing headaches, fevers, etc.The better the immune system the more side effects.t is odd thou,the mother of my next door neighbor is like 85 years old and she didn't feel anything,fresh like a Rose...seems the side effects vary from person to person.