Symptom definition:

See also

Immunization project Education efforts Information for parents Immunization resources Information for providers Reactions Reasons to immunize Vaccine safety

• You believe your child is having a reaction to an immunization
• Reactions to DTaP (Diphtheria, Tetanus, Pertussis), MMR (Measles, Mumps, Rubella), polio, Hemophilus influenzae type b, Hepatitis B, influenza, chickenpox (varicella) and pneumococcus vaccines are covered below
• 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 above 100.4°F (38°C) rectally. Exception: occurs within 24 hours after DTaP shot
• Fever above 104°F
• High-pitched, unusual crying for more than 1 hour
• Crying continuously for more than 3 hours
• Redness or red streak around the injection site bigger than 1 inch
• Redness around the injection site persists for more than 48 hours (2 days)

Call your doctor within 24 hours (during regular office hours) if:

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

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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 (e.g. Tylenol ®) or ibuprofen by mouth.
• Fever: For fevers above 100.4°F (38°C) rectally, give acetaminophen (e.g. Tylenol ®) or ibuprofen (e.g. Advil ®). It is okay to use ibuprofen if child is older than 6 months.
• Call Your Doctor If fever lasts more than 3 days; pain lasts more than 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 in 51percent of children lasts for 24 to 48 hours
• Fever in 47 percent of children lasts for 24 to 48 hours
• Mild drowsiness (32 percent), fretfulness (53 percent) or poor appetite (21 percent) lasts for 24 to 48 hours

3. Measles vaccine reactions:

• The measles vaccine can cause a fever (10 percent of children), and rash (5 percent 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.
• Call your doctor if rash becomes very itchy; rash changes to purple spots; rash lasts more than 3 days.

4. Mumps or rubella vaccine:

• There are no reactions except for an occasional sore injection site

5. Polio vaccine:

•  There are no serious reactions to oral polio vaccine. Polio vaccine by injection occasionally causes some muscle soreness

6. Hib vaccine (Hemophilus influenzae type b vaccine):

• No serious reactions reported
• Sore injection site or mild fever only occurs in 1.5 percent of children.

7. Hepatitis B virus vaccine (HBV):

• No serious reactions reported.
• Sore injection site occurs in 30 percent of children and mild fever in 3 percent of children.
• Because fever from the vaccine is rare, any infant less than 3 months with a fever following the vaccine should be examined.

8. Influenza virus vaccine:

• Pain, tenderness or swelling at the injection site occurs within 6 to 8 hours in 10 percent of children.
• Fever 101° to 103°F (38.4° to 39.5°C) occurs in 18 percent of children. Fevers mainly occur in young children.

9. Chickenpox vaccine:

• Pain or swelling at the injection site for 1 to 2 days (in 19 percent of children).
• Fever lasting 1 to 3 days begins 17 to 28 days after the vaccine (in 14 percent). Give acetaminophen (e.g. Tylenol®) or ibuprofen (Advil®) for fever above 100.4°F (38°C) rectally. 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 percent). Chickenpox-like vaccine rash (usually 5 lesions) scattered over the body (in 4 percent). 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®.

10. Pneumococcus vaccine:

• Pain, tenderness, swelling OR redness at the injection site in 15-30 percent. · Mild fever below 102°F (39°C) in 15 percent for 1-2 days · No serious reactions

Source: Parent Care for Pediatric Symptoms. Barton D. Schmitt, MD, FAAP. Copyright © 2000.