genetic material together. This detergent pulls the fat out like a grease stain, leaving free virus bits behind—they’re less likely to cause side effects than the whole virus.
Gelatin
All gelatin is made from animal collagen; this version, which keeps vaccine components stable during storage and shipping, comes from pig parts.
People who are allergic to Jell-O, marshmallows, or gummy bears (made with pig- or cow-derived gelatin) could have an anaphylactic reaction to the shot, but those are rare overall: just one per million doses.
Thimerosal
Some people (wrongly) think this preservative makes vaccines dangerous. Actually, it makes multidose vials safer, keeping them free of bacteria and fungi even after repeated needle insertions.
Your body breaks it down into thiosalicylate and ethylmercury—that’s different from the methylmercury in seafood, which can build up in your body. This form is usually gone within weeks.
Side Effects from the flu shot
Traces of Octoxinol-10 has been found in flu shots as well. It is commonly used as a vaginal spermicide.
People who have gotten the flu shot have reported symptoms ranging from:
- tenderness, redness, and swelling of the skin around the injection site
- fever
- fatigue
- headache
Contact your doctor or go to an emergency room right away if you have any of these more serious side effects, which may indicate an allergic reaction:
- trouble breathing or wheezing
- swelling of the eyes or lips
- hives
- weakness
- fast heartbeat
- dizziness