SIDE EFFECTS: Pain/redness/swelling at the injection site, fever, irritability, increased crying, loss of appetite, and increased sleeping may occur. Less common side effects may include bruising at the injection site, vomiting, runny nose, stuffy nose, cold symptoms, cough, and diarrhea. If any of these effects persist or worsen, tell your infant's doctor or pharmacist promptly.

Remember that your child's doctor has prescribed this medication because he or she has judged that the benefit to your infant is greater than the risk of side effects. Many infants using this medication do not have serious side effects. Report all side effects to the doctor before your infant receives the next injection.

Tell your infant's doctor immediately if any of these unlikely but serious side effects occur: unusually fast/irregular heartbeat, fainting.

Tell your infant's doctor immediately if any of these rare but very serious side effects occur: inability to make muscles of the legs/arms/face work (paralysis), seizures, easy bruising/bleeding, mental/mood changes (e.g., unusual behavior, severe drowsiness, stiff neck, closing eyes/turning away from bright light).

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice your infant having any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

Contact your doctor for medical advice about side effects. The following numbers do not provide medical advice, but in the US, you may report side effects to the Vaccine Adverse Event Reporting System (VAERS) at 1-800-822-7967. In Canada, you may report side effects to Health Canada at 1-866-234-2345.

Read the Comvax (haemophilus b conjugate and hepatitis b vaccine) Side Effects Center for a complete guide to possible side effects »

PRECAUTIONS: Before using this medication, tell the doctor or pharmacist if your child is allergic to it; or to yeast or latex; or if your child have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell the doctor or pharmacist your infant's medical history, especially of: bleeding problems (e.g., hemophilia, low platelets, anticoagulant treatment), current illness with fever.

If your child has decreased immune function from other medications (see also Drug Interactions) or other illness (e.g., HIV, leukemia, lymphoma, other cancer), the child's body may not make enough antibodies to protect them from Haemophilus influenza b or hepatitis B infection. Antibody levels should be checked after the vaccine series.