I get them every year and have done so for quite some time without any subsequent ill effects. Maybe forty years ago they used live viruses but now they are killed viruses. If you got sick after taking a flu shot then I suspect you were already infected with something. Sure it only protects you against a few strains that scientists try to predict are the most prevalent. Just because you got one flu during the year doesn't necessarily mean the flu shot did not work. Maybe you would have gotten two. It is hard to prove a negative.
