Immunization Reactions  

This Care Guide Covers:

  • You think your child is having a reaction to a recent immunization (vaccine)
  • Types of Reactions: Reactions at the shot site (such as pain, swelling, redness) and general reactions (such as a fever or being fussy)
  • Reactions to these vaccines are covered:
  • Chickenpox (varicella)
  • DTaP (Diphtheria, Tetanus, Pertussis)
  • Hemophilus influenzae type b
  • Hepatitis A
  • Hepatitis B
  • Human Papilloma virus
  • Influenza
  • MMR (Measles, Mumps, Rubella)
  • Meningococcal
  • Polio
  • Pneumococcal and
  • Rotavirus

When to Call Your Doctor

Call 911 Now (your child may need an ambulance) If
  • Trouble breathing or swallowing
  • Not moving or very weak
  • Can't wake up
  • You think your child has a life-threatening emergency
Call Your Doctor Now (night or day) If
  • Your child looks or acts very sick
  • Hard to wake up
  • Age under 12 weeks old with fever. (Caution: Do NOT give your baby any fever medicine before being seen.)
  • Fever over 104° F (40° C)
  • High-pitched crying lasts more than 1 hour
  • Crying nonstop lasts more than 3 hours
  • You think your child needs to be seen urgently
Call Your Doctor Within 24 Hours (between 9 am and 4 pm) If
  • You think your child needs to be seen, but not urgently
  • Redness or red streak starts more than 48 hours (2 days) after the shot
  • Redness around the shot becomes larger than 3 inches (7.5 cm)
  • Fever lasts more than 3 days
  • Fever returns after gone for more than 24 hours
  • Measles vaccine rash (starts day 6 to 12 after shot) lasts more than 4 days
Call Your Doctor During Weekday Office Hours If
  • You have other questions or concerns
  • Redness or red streak around shot is larger than 1 inch (2.5 cm)
  • Redness, swelling or pain is getting worse after 3 days
  • Fussiness from vaccine lasts more than 3 days
Parent Care at Home If
  • Normal immunization reaction
Causes & Health Information

Symptoms

  • Shot sites can have swelling, redness and pain. Most often, these symptoms start within 24 hours of the shot. They most often last 2 to 3 days. With the DTaP vaccine, they can last up to 7 days.
  • Fever with most vaccines begins within 24 hours and lasts 1 to 2 days.
  • With the MMR and chickenpox shots, fever and rash can occur. These symptoms start later. They usually begin between 1 and 4 weeks.
  • Severe allergic reactions are very rare, but can occur with any vaccine. They start within 2 hours.
CARE ADVICE FOR IMMUNIZATION REACTIONS

Treatment for Common Immunization Reactions
  1. What You Should Know:
    • Immunizations (vaccines) protect your child against serious diseases.
    • All of these reactions mean the vaccine is working.
    • Your child's body is making new antibodies to protect against the real disease.
    • Most of these symptoms will only last 2 or 3 days.
    • There is no need to see your child's doctor for normal reactions.
    • Medicine is only needed if your child has pain. Also, use a fever medicine for fever over 102° F (39 ° C).
    • Here is some care advice that should help.
  2. Reaction at Shot Site:
    • Cold Pack: For pain at the shot site, use a cold pack. You can also use put ice in a wet washcloth on the sore shot site. Use for 20 minutes as needed.
    • Pain Medicine: To help with the pain, give acetaminophen (such as Tylenol) or ibuprofen. Use as needed. See Dose Table.
    • Hives at the Shot Site: If itchy, can put on 1% hydrocortisone cream. No prescription is needed. Use twice daily as needed.
  3. Fever:
    • Fever with most vaccines begins within 12 hours and lasts 2 to 3 days. This is normal, harmless and possibly helpful.
    • For fevers above 102° F (39° C), give acetaminophen. If over 6 months old, can give ibuprofen. See Dose Tables.
    • For all fevers: Give extra fluids. Do not use too many clothes or blankets on your child.
  4. General Reaction:
    • All vaccines can cause mild fussiness, crying and restless sleep. This is usually due to a sore shot site.
    • Some children sleep more than usual. A decreased appetite and activity level are also common.
    • These symptoms are normal. They do not need any treatment.
    • They will usually go away in 24-48 hours.
  5. Call Your Doctor If:
    • Redness larger than 1 inch (2.5 cm) for first 3 DTaP shots or any other shot
    • Redness larger than 2 inches (5 cm) with 4th DTaP
    • Redness larger than 3 inches (7.5 cm) with 5th DTaP
    • Pain, swelling or redness gets worse after 3 days (or lasts more than 7 days)
    • Fever starts after 2 days (or lasts more than 3 days)
    • Your child becomes worse
Specific Immunization Reactions
  1. Chickenpox Vaccine:
    • Pain or swelling at the shot site for 1 to 2 days. (20% of children)
    • Mild fever lasting 1 to 3 days begins 17 to 28 days after the shot (15%). Give acetaminophen or ibuprofen for fever over 102° F (39°C).
    • Never give aspirin for fever, pain or within 6 weeks of getting the shot. Reason: Risk of Reye syndrome, a rare but serious brain disease.
    • Chickenpox-like rash (usually 2 red bumps) at the shot site (3%)
    • Chickenpox-like rash (usually 5 red bumps) scattered over the body (4%)
    • This mild rash begins 5 to 26 days after the shot. Most often, it lasts a few days.
    • Children with these rashes can go to child care or school. (Reason: For practical purposes, vaccine rashes are not spread to others)
    • EXCEPTION: Do not go to school if red bumps drain fluid and are widespread. Reason: can be actual chickenpox.
    • Caution: If vaccine rash contains fluid, cover it with clothing or a Band-Aid.
  2. DTaP or DT Vaccine:
    • The following harmless reactions to DTaP can occur:
    • Pain, tenderness, swelling and redness at the shot site is the main side effect. This happens in 25% of children. It lasts for 3 to 7 days.
    • Fever (in 25% of children) and lasts for 24 to 48 hours
    • Mild drowsiness (30%), fretfulness (30%) or poor appetite (10%) and lasts for 24 to 48 hours.
    • Large swelling over 4 inches (10 cm) arm can follow the later doses of DTaP. The area of redness is smaller. This usually occurs with the 4th or 5th dose. It occurs in 5% of children. Most children can still move the leg or arm normally. The area of redness is smaller.
    • The large thigh or upper arm swelling goes away without treatment by day 3 (60%) to day 7 (90%).
    • This is not an allergy. Future DTaP vaccines are safe to give.
  3. Hemophilus Influenza Type B Vaccine (Hib):
    • No serious reactions reported.
    • Sore injection site or mild fever only occurs in 2% of children.
  4. Hepatitis A Vaccine:
    • No serious reactions reported.
    • Sore injection occurs in 20% of children.
    • Loss of appetite occurs in 10% of children.
    • Headache occurs in 5% of children.
    • Most often, no fever is present.
    • If these symptoms occur, they most often last 1-2 days.
  5. Hepatitis B Virus Vaccine (HBV):
    • No serious reactions reported.
    • Sore shot site occurs in 30% of children and mild fever in 3% of children.
    • Fever from the vaccine is rare. Any baby under 2 months with a fever after this shot should be examined.
  6. Influenza Virus Vaccine:
    • Pain, tenderness or swelling at the injection site occurs within 6 to 8 hours. This happens in 10% of children.
    • Mild fever under 103° F (39.5° C) occurs in 20% of children. Fevers mainly occur in young children.
    • Nasal Influenza Vaccine: Congested or runny nose, mild fever.
  7. Measles Vaccine:
    • The measles shot can cause a fever (10% of children) and rash (5% of children). This occurs about 6 to 12 days after the shot.
    • Mild fever under 103° F (39.5°C) in 10% and lasts 2 or 3 days.
    • The mild pink rash is mainly on the trunk and lasts 2 or 3 days.
    • No treatment is needed. The rash cannot be spread to others. Your child can go to child care or to school with the rash.
    • Call Your Doctor If:
      • Rash changes to blood-colored spots
      • Rash lasts more than 3 days
  8. Meningococcal Vaccine:
    • No serious reactions.
    • Sore shot site for 1 to 2 days occurs in 50%. Limited use of the arm occurs in 15% of children.
    • Mild fever occurs in 5%, headache in 40% and joint pain in 20%
    • The vaccine never causes meningitis.
  9. Mumps or Rubella Vaccine:
    • There are no serious reactions.
    • Sometimes, a sore shot site can occur.
  10. Papillomavirus Vaccine:
    • No serious reactions.
    • Sore injection site for few days in 80%.
    • Mild redness and swelling at the shot site (in 25%).
    • Fever over 100.4° F (38.0° C) in 10% and fever over 102° F (39° C) in 2%.
    • Headache in 30%.
  11. Pneumococcal Vaccine:
    • No serious reactions.
    • Pain, tenderness, swelling OR redness at the injection site in 20%.
    • Mild fever under 102° F (39° C) in 15% for 1-2 days.
  12. Polio Vaccine:
    • Polio vaccine given by shot sometimes causes some muscle soreness.
    • Polio vaccine given by mouth is no longer used in the U.S.
  13. Rotavirus Vaccine:
    • No serious reactions to this vaccine given by mouth.
    • Mild diarrhea or vomiting for 1 to 2 days in 3%.
    • No fever.

And remember, contact your doctor if your child develops any of the "Call Your Doctor" symptoms.
DOWNLOAD THE APP

This free app has a symptom checker,
dosage tables for common medications,
home health advice and more.

Apple version of the MD 4KIDS app
Android version of the MD 4KIDS app

Disclaimer: This information is not intended be a substitute for professional medical advice. It is provided for educational purposes only. You assume full responsibility for how you choose to use this information.


Author and Senior Reviewer: Barton D. Schmitt, M.D.

Last Reviewed: 9/1/2012

Last Revised: 12/15/2012

Content Set: Child Symptom Checker

Copyright 1994-2012 Barton D. Schmitt, M.D.