What are the negative effects of a flu shot?

Several: Generally any reaction is possible with flu or any immunization. You can still get the flu , or get headache bodyaches. You could get a site infection from the injection. Some people have strange reactions. I like to think positively and hope that we prevent you from getting flu. There is a long list of things on the flu websites i would probably check that out.

Potential side effec: Flu shot side effects may include: slight swelling, redness or pain at vaccination site. If headache, nausea, fever or muscular pain occur they usually resolve within one to two days. You won't get the flu from a flu shot because the virus either contains inactivated virus or doesn't have virus particles in it. Severe side effects are rare.