Effectiveness

• The Hib vaccine produces an immune response quite effectively: After two or three doses, 95 to 100 percent of infants are protected from Hib disease.
  
  

Very Low Risk

• Hib vaccine is very safe; most Hib vaccine recipients experience no problems. It is extremely rare for Hib vaccine to cause serious harm.
  
  

Who Should not get Hib Vaccine?

• Certain people should not get Hib vaccine, including those who have had a life-threatening allergic reaction after getting Hib vaccine previously, and children younger than 6 weeks.
  
  

Minor Reactions

• Typical mild side-effects of Hib vaccination can include redness, warmth, or swelling at the injection site, or a fever more than 101 degrees F. These problems should resolve after 2 to 3 days.
  
  

Moderate to Severe Reactions

• As with any medication, vaccines can potentially cause serious problems. These can include severe allergic reactions. Watch for hives, paleness, weakness, fast heartbeat, dizziness, hoarseness or wheezing, or difficulty breathing. If you notice these signs in someone within a few hours after a Hib vaccination, call a doctor immediately.