Why are vaccines more painful than a normal yearly shot like the flu shot?

Flu shots r vaccines: Some vaccines hurt. They are an essential part of preventive medicine and do far more good than the pain or other potential side effects that they may cause. Site of injection, technique, density or composition of the vaccine may make some more painful than others. topical anesthetics or applying cold sprays to the area may help.

I'm not sure what: vaccines you are referring to. One vaccine that patients often say hurts more than the others is Gardasil. The Flu vaccine actually does often cause pain, as does a tetanus vaccine. The soreness is from the body's immune response to the vaccine, which means it is starting to work. Some of the pain is also from the needlestick, itself, especially those vaccines which go into the muscle.