Miscellaneous > Fever, Infections and Crying > Immunization Reactions

Immunization Reactions

Symptom Definition

  • You believe your child is having a reaction to an immunization
  • Reactions to DTP (Diphtheria, Tetanus, Pertussis), MMR (Measles, Mumps, Rubella), polio, Hemophilus influenzae type b, Hepatitis B, influenza, chickenpox (varicella) and pneumococcus vaccines are covered
  • Most reactions at the injection site occur within 2 days and most general reactions or fever within 7 days
  • Severe allergic reactions are very rare, but can occur with any vaccine

Call 911 Now (your child may need an ambulance) If

  • Difficulty with breathing or swallowing
  • Limp, weak or not moving
  • Unresponsive or difficult to awaken

Call Your Doctor Now (night or day) If

  • Your child looks or acts very sick
  • Age less than 12 weeks with fever > 100.4°F (38°C) rectally (Exception: occurs within 48 hours after DTP shot)
  • Fever > 104°F
  • Crying continuously for > 3 hours
  • Redness or red streak around the injection site bigger than 1 inch
  • Redness around the injection site persists > 48 hours (2 days)

Call Your Doctor Within 24 Hours (between 9 and 4) If

  • You think your child needs to be seen
  • Fever present > 3 days
  • Pain, tenderness, or swelling at the injection site persists > 3 days
  • Measles vaccine rash (onset day 7 to 10) persists > 3 days

Call Your Doctor During Weekday Office Hours If

  • You have other questions or concerns

Parent Care at Home If

  • Normal immunization reaction and you don't think your child needs to be seen

Home Care Advice for Immunization Reactions

  1. Local Reaction to the Injection (All vaccines except oral polio):
    • Pain: For initial pain or tenderness at the injection site
      • Apply ice to the area for 20 minutes once.
      • Give acetaminophen or ibuprofen by mouth
    • Fever: For fevers > 102°F (39°C), give acetaminophen (ok to use ibuprofen if > 6 months old)
    • Call Your Doctor If
      • Fever lasts > 3 days.
      • Pain lasts > 3 days.
      • Injection site starts to look infected.
      • Your child becomes worse or develops any of the "Call Your Doctor" symptoms
  2. For DTaP, DTP or DT Reactions: The following harmless reactions to DTP can occur: (Fever and other general reactions are less common with the newer DTaP)
    • Pain, tenderness, swelling or redness at the injection site lasts for 24 to 48 hours (in 51% of children).
    • Fever lasts for 24 to 48 hours (in 47% of children).
    • Mild drowsiness (32%), fretfulness (53%) or poor appetite (21%) for 24 to 48 hours also occurs.
  3. Measles Vaccine Reactions:
    • The measles vaccine can result in a fever (10% of children), and rash (5% of children) about 7 to 10 days following the injection. The fever is usually between 101 and 103°F (38.4° and 39.5°C) and lasts 2 or 3 days. The mild pink rash is mainly on the trunk and lasts 2 or 3 days. No treatment is necessary. Your child is not contagious.
  4. Call Your Doctor If
    • Rash becomes very itchy.
    • Rash changes to purple spots.
    • Rash lasts > 3 days.
  5. Mumps or Rubella Vaccine:
    • There are no reactions except for an occasional sore injection site.
  6. Polio Vaccine:
    • There are no serious reactions to oral polio vaccine. Polio vaccine by injection occasionally causes some muscle soreness.
  7. Hib Vaccine (Hemophilus influenzae Type b Vaccine):
    • No serious reactions reported.
    • Sore injection site or mild fever only occurs in 1.5% of children
  8. Hepatitis B Virus Vaccine (HBV):
    • No serious reactions reported.
    • Sore injection site occurs in 30% of children and mild fever in 3% of children.
    • Because fever from the vaccine is rare, any infant < 3 mo with a fever following the vaccine should be examined
  9. Influenza Virus Vaccine:
    • Pain, tenderness or swelling at the injection site occurs within 6 to 8 hours in 10% of children.
    • Fever 101 to 103°F (38.4° to 39.5°C) occurs in 18% of children. Fevers mainly occur in young children.
  10. Chickenpox Vaccine:
    • Pain or swelling at the injection site for 1 to 2 days (in 19% of children)
    • Fever lasting 1 to 3 days begins 17 to 28 days after the vaccine (in 14%) Give acetaminophen or ibuprofen for fever > 102°F (39°C). Never give aspirin for fever, pain or within 6 weeks of receiving the vaccine (Reason: risk of Reye's syndrome - a rare but serious brain disease)
    • Chickenpox-like vaccine rash (usually 2 lesions) at the injection site (in 3%)
    • Chickenpox-like vaccine rash (usually 5 lesions) scattered over the body (in 4%)
    • This mild rash begins 5 to 26 days after the vaccine and usually lasts a few days.
    • Children with these vaccine rashes can go to day care or school. (Reason: for practical purposes, vaccine rashes are not contagious) EXCEPTION: avoid school if widespread, weepy lesions (Reason: probably actual chickenpox).
    • Precaution: if vaccine rash contains fluid, cover it with clothing or Band-Aid.
  11. Pneumococcus Vaccine:
    • Pain, tenderness, swelling OR redness at the injection site in 15-30%
    • Mild fever < 102°F (39°C) in 15% for 1-2 days
    • No serious reactions