Several folks here at my office got it and had sore arms for days. One called in sick for a day. I always got adverse reactions from the flu shot and decided a decade or so ago that I wasn't getting one anymore. I did get the flu about five years ago, but my doctor told me it wasn't the strain in the flu shot, so it wouldn't have done me any good anyway. Feeling crappy for a couple days every year versus maybe getting sick once in a decade isn't worth it to me. If it was 100% effective, I'd consider it, but most years, it's a long way off that.