Haemophilus Influenzae Type B Vaccine

Your child needs to be given a vaccine called haemophilus influenzae (say: he-MOF-uh-luhs in-floo-EN-zuh) type B vaccine. This information sheet explains what haemophilus influenzae type B vaccine does, how it is given, and what side effects or problems your child may have when he or she takes this medicine.

What is haemophilus influenzae?

Haemophilus influenzae type B (Hib) vaccine is given to children under 5 years old to protect them against certain serious infections, such as meningitis and pneumonia. Haemophilus influenzae type B vaccine causes the body to make antibodies against a certain bacteria or germ called Haemophilus influenzae type B.

Hib vaccine will protect 90 out of 100 children against serious Haemophilus influenzae infections. If a person who has received the vaccine is infected, the infection may be milder.

This vaccine does not protect against the flu.

You may hear Haemophilus influenzae type B vaccine called Hib vaccine, or by its brand names Act-HIB, PedvaxHIB, or Pentacel. Hib vaccine comes in an injection form. Sometimes, Hib vaccine is combined with other vaccines in a single injection. 

Before giving haemophilus influenzae to your child

Tell your doctor if your child has any of the following conditions:

  • serious allergic reaction to Hib vaccine
  • blood clotting problems

Talk with your doctor or pharmacist if your child has any of the following conditions. This medicine may not be right for your child if he/she:

  • Hib vaccination should be postponed and your child should get the vaccine another day. If your child has a cold, mild diarrhea (watery bowel movements), or mild fever, your child can get the Hib vaccine as scheduled.
  • is immunocompromised (body’s natural immunity is weakened) or if your child is getting immunosuppressants (medicines that lower the body’s natural immunity, such as cancer treatment or anti-rejection medications after an organ transplant)
    Your child will not make enough antibodies against the germ haemophilus influenzae if given the vaccine. Your child may get the Hib vaccine before the transplant/treatment or after treatment. Your doctor will tell you when your child get can this vaccine. 
  •  At such a young age, your child may not make enough antibodies to protect against Hib disease.

How will your child get haemophilus influenzae?

  • Hib vaccine is a liquid that is given by the doctor or nurse by a needle into the thigh (upper leg). If your child is older, Hib vaccine may be given as a needle in the upper arm.
  • Your child will get this needle at the doctor’s office or in the hospital.
  • Your child will get a series of 2 or 3 injections (depending upon the vaccine used) several months apart and then a booster shot usually around 1 year later. 
  • Usually, Hib vaccine is given at the same time as other vaccines [such as diphtheria, pertussis (whooping cough), tetanus, and polio].
  • After your child gets Hib vaccine or any other vaccine, your doctor will write down when your child got the vaccine in the yellow Immunization Record card. Keep this card safe. 

For more information about when this and other vaccines should be given, see "Immunization Schedule."

What should you do if your child misses a dose of haemophilus influenzae?

  • Your child should get the next injection as soon as possible. Please speak to your doctor or nurse. Your child does not usually need to restart the series of injections.

How long does haemophilus influenzae take to work?

Usually three injections are needed before your child is fully protected against haemophilus influenzae. 

What are the possible side effects of haemophilus influenzae?

Your child may have some of these side effects when he or she is given the Hib vaccine. Check with your child's doctor if your child continues to have any of these side effects and they do not go away or they bother your child:

  • redness, swelling, or tenderness at the injection site
  • small painless lump at the injection site
  • slight fever: high temperature up to 40°C (104°F)
  • drowsiness or loss of interest
  • irritability or fussiness
  • loss of appetite/does not want to eat

Call your child's doctor right away or take your child to the Emergency Department if your child has any of these side effects:

  • seizures
  • high fever over 40°C (104°F)
  • any sign of an allergic reaction including: rash, severe problems breathing, or changes in heart rate

What safety measures should you take when your child is using haemophilus influenzae?

To help reduce pain or discomfort, you can do the following:

  • Apply a cool, damp cloth to the site of injection to ease the pain.
  • If your child is older than 3 months, you may also apply EMLA cream or patch to the site of injection before your child gets the Hib vaccine.
  • To use EMLA, apply the cream or patch at least 1 hour before the appointment. For the cream, use an amount about the size of a credit card and cover with an air-tight dressing. Be careful not to use more cream than needed. 
  • If your child is experiencing severe discomfort after the injection, you may give acetaminophen (Tylenol or Tempra).

Check with your child’s doctor or pharmacist before giving your child any other medicines (prescription, non-prescription, herbal, or natural products).

If your child develops a fever, you may give acetaminophen (Tylenol or Tempra). Do not give acetylsalicylic acid​ (ASA or Aspirin) to your child. 

What other important information should you know about haemophilus influenzae?

Keep a list of all medications your child is on and show the list to the doctor or pharmacist.

Keep medicine out of your child’s sight and reach and locked up in a safe place. If your child takes too much medicine, call the Ontario Poison Centre at one of these numbers. These calls are free.

  • Call 416-813-5900 if you live in Toronto.
  • Call 1-800-268-9017 if you live somewhere else in Ontario.
  • If you live outside of Ontario, call your local Poison Information Centre

Disclaimer: The information in this Family Med-aid is accurate at the time of printing. It provides a summary of information about haemophilus influenzae type B vaccine and does not contain all possible information about this medicine. Not all side effects are listed. If you have any questions or want more information about haemophilus influenzae type B vaccine, speak to your healthcare provider.

Jennifer Drynan-Arsenault, BSc, RPh, ACPR