Immunization Reactions

Disponible En Espanol

Care at Home

  • 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.
  • 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.
  • 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.
  • 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
  • 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.
  • 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.
  • HEMOPHILUS INFLUENZA TYPE B VACCINE (HIB): * No serious reactions reported. * Sore injection site or mild fever only occurs in 2% of children.
  • 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.
  • 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.
  • 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.
  • 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
  • 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.
  • MUMPS OR RUBELLA VACCINE: * There are no serious reactions. * Sometimes, a sore shot site can occur.
  • 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.
  • 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.
  • ROTAVIRUS VACCINE: * No serious reactions to this vaccine given by mouth. * Mild diarrhea or vomiting for 1 to 2 days in 3%. * No fever.
  • 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%.
  • 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.


The information contained in these topics is not intended nor implied to 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.

Always seek the advice of your physician or other qualified healthcare provider before starting any new treatment or discontinuing an existing treatment. Talk with your healthcare provider about any questions you may have regarding a medical condition. Nothing contained in these topics is intended to be used for medical diagnosis or treatment.

  • Not a Substitute - The information and materials in Pediatric HouseCalls Symptom Checker should not be used as a substitute for the care and knowledge that your physician can provide to you.
  • Supplement - The information and materials presented here in Pediatric HouseCalls Symptom Checker are meant to supplement the information that you obtain from your physician. If there is a disagreement between the information presented herein and what your physician has told you -- it is more likely that your physician is correct. He or she has the benefit of knowing your child's medical problems.
  • Limitations - You should recognize that the information and materials presented here in Pediatric HouseCalls Symptom Checker have the following limitations, in comparison to being examined by your own physician:
    • You can have a conversation with your child's doctor.
    • Your child's doctor can perform a physical examination and any necessary tests.
    • Your child could have an underlying medical problem that requires a physician to detect.
    • If your child is taking medications, they could influence how he experiences various symptoms.

If you think that your child is having a medical emergency, call 911 or the number for the local emergency ambulance service NOW!

And when in doubt, call your child's doctor NOW or go to the closest emergency department.

The search for nearby emergency and urgent care facilities is based upon Google search parameters. You will get results based on how facilities manage their website information.

By using this website, you accept the information provided herein "AS IS." Neither publishers nor the providers of the information contained herein will have any liability to you arising out of your use of the information contained herein or make any expressed or implied warranty regarding the accuracy, content, completeness, reliability, or efficacy of the information contained within this website.