A vaccine, like any medicine, is capable of causing serious problems, such as severe allergic reactions. The risk of Hib vaccine causing serious harm or death is extremely small.

Most people who get Hib vaccine do not have any problems with it.

Mild Problems

• Redness, warmth, or swelling where the shot was given (up to 1/4 of children)
  
• Fever over 101°F (up to 1 out of 20 children)
  

If these problems happen, they usually start within a day of vaccination.
They may last 2-3 days.