A Most common reactions seen after getting vaccines

  • No reaction at all.
  • Fever for 2-3 days the height of the fever may vary from low grade to high. Treat the fever with the appropriate dose of fever reducing medication. Your child should feel better in about 30 minutes.
  • Fussiness for 2-3 days.
  • Redness at the site of injection for 2-3 days.
  • Lump/knot under the site of the injection that can be present for weeks to months, you can place a cool compress on the area or do nothing at all. Either way it will go away on its own.
  • MMR and Varicella vaccines can give a fever or rash or both 1-2 weeks AFTER the date of the injection The rash after the MMR vaccine looks like small red bumps that may cover your child from head to toe, but are most common on the torso. The rash should not bother your child, is not contagious, and will self-resolve in about 1 week. The rash after the varicella vaccine can look like mild chicken pox (a few clear fluid bumps on a red base). Because the rash is so mild, it should not bother your child.
  • DTaP (especially seen at the 18 month and 4 year visit) can cause the whole side of the thigh (18 month) or the whole side of the arm (4 year) to become red, swollen and hot. This usually bothers the parents more than the child. If your child is happy, no need to do anything. You can use pain reliever for any pain they may have and Benadryl or topical 1% hydrocortisone for any itching. This usually goes away in 2-3 days.


Call our office if: Fever for >72 hours Inconsolable despite giving pain relievers (Tylenol/Motrin).