If you dig deep enough I'm sure you will find that almost every bug in history would have had someone hurt or killed from it.
I also know that some of the chemical defenses use to protect ourselves are deemed acceptable because they harm you to a lesser extent but they still harm you. It quickly turns into a game of numbers and percentages where you are likely to contract something and it will hurt you.
Now I've decided to take the fit and healthy option, if I look after my body I'm less likely to be seriously effect by the next bug that comes around the corner, I can't rely on the fact that some pill will protect me alone! But I'm not doing this because I'm paranoid about it just I know that my body works and functions better after good food and exercise.
Giving up smoking, crap food and getting some regular exercise is the best defense and we all know it, so stop kidding yourself and putting it off.
If we all were a bit fitter and healthier we wouldn't worry so much about the next bug coming around the corner.
Also FEAR is the strongest emotion, the media uses it all the time to make us take notice. I hate being manipulated so I chose not to watch or read news sources that use fear.