I've never had a bad reaction to a flu shot nor has anyone that I've personally ever known to get them. There are far more people who get it and have no side effects than the ones who do, and it will protect you from H1N1. I think there's a higher likelihood that you would catch the flu than have a bad reaction to the vaccine. With that being said, though, it's of course up to your decision. There is a risk of side effects, but it's likely minimal. Everything has side effects. If you do choose to not get the vaccine, know that I got H1N1 when it was a pandemic a few years ago and the death rate from it was higher, and I made it through, even with a cruddy immune system. For every person that gets the flu and is hospitalized/passes away, there are thousands upon thousands more people who recover just fine, but you won't hear about them in the news.