What is The Most Effective Self Defense Method?
Crime rates all over the world drop during Winter and at least part of that probably has to do with people getting the flu. Having the flu is the closest thing you can get to actually having super powers. You have the ability to projectile vomit disease and spray virus juice everywhere with a simple sneeze. You are basically a walking biohazard and that makes criminals take warning.
No one wants to try and mug someone who is oozing deadly virus soaked bacteria from every facial orifice. Most criminals don't bother getting flu shots because that's something only wholesome people who care about others do, so that means they're even more vulnerable to a biological warfare defense than the average person. They may be criminal scum, but they do know what it's like to have Influenza and no one wants to deal with that. When you're a criminal you need to be out on the streets doing crimes every night. You can't be curled up in bed sipping NyQuil and shivering in your favorite blanket hallucinating and wishing you were dead.
The flu is the penultimate equalizer just second to death itself and because of that, having the flu is just about as good of a self defense method as having a loaded gun. Everything has a silver lining and the silver lining of getting the flu is no one's going to mug you as long as you plan to spit and cough right in their face while it's happening.