Comvax Side Effects Center
Medical Editor: John P. Cunha, DO, FACOEP
Comvax [Haemophilus b Conjugate (Meningococcal Protein Conjugate) and Hepatitis B (Recombinant) Vaccine] is an immunization used to help prevent Haemophilus B (a type of influenza) and Hepatitis B (a viral disease) in children. This vaccine works by exposing your child to a small dose of the bacteria or virus, which causes the body to develop immunity to the disease. This vaccine will not treat an active infection. This medication is available in generic form. Common side effects include pain/redness/swelling at the injection site, fever, irritability, increased crying, loss of appetite, and increased sleeping. Less common side effects may include bruising at the injection site, vomiting, runny nose, stuffy nose, cold symptoms, cough, and diarrhea.
Comvax is a 3-dose combination series that aligns with routine doctor visits at 2, 4, and 12 to 15 months of age. Comvax may interact with steroids, medicines to treat or prevent organ transplant rejection, or medications to treat psoriasis, rheumatoid arthritis, or other autoimmune disorders. Tell your doctor all medications and supplements you use and all vaccines your child recently received. This vaccine is not for use in adults, therefore it is unlikely to be used during pregnancy or while breastfeeding; consult your doctor.
Our Comvax [Haemophilus b Conjugate (Meningococcal Protein Conjugate) and Hepatitis B (Recombinant) Vaccine] Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What is Patient Information in Detail?
Easy-to-read and understand detailed drug information and pill images for the patient or caregiver from Cerner Multum.
Comvax in Detail - Patient Information: Side Effects
Your child should not receive a booster vaccine if he or she had a life-threatening allergic reaction after the first shot.
Keep track of any and all side effects your child has after receiving this vaccine. When the child receives a booster dose, you will need to tell the doctor if the previous shots caused any side effects.
Becoming infected with haemophilus B or hepatitis A is much more dangerous to your child's health than receiving the vaccine to protect against these diseases. Like any medicine, this vaccine can cause side effects, but the risk of serious side effects is extremely low.
Get emergency medical help if your child has any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if the child has any of these serious side effects:
- extreme drowsiness, fainting;
- fussiness, irritability, crying for an hour or longer;
- seizure (black-out or convulsions); or
- high fever.
Less serious side effects include:
- redness, pain, tenderness, swelling, or a hard lump where the shot was given;
- diarrhea, loss of appetite, mild vomiting;
- mild fussiness or crying;
- joint pain, body aches; or
- mild fever.
This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.
Read the entire detailed patient monograph for Comvax (Haemophilus b Conjugate and Hepatitis B Vaccine) »
What is Patient Information Overview?
A concise overview of the drug for the patient or caregiver from First DataBank.
Comvax Overview - Patient Information: Side Effects
Infrequently, temporary symptoms such as fainting/dizziness/lightheadedness, vision changes, numbness/tingling, or seizure-like movements have happened after vaccine injections. Tell your health care provider right away if your child has any of these symptoms soon after receiving an injection. Sitting or lying down may relieve symptoms.
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.
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 entire patient information overview for Comvax (Haemophilus b Conjugate and Hepatitis B Vaccine)»
What is Prescribing information?
The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.
Comvax FDA Prescribing Information: Side Effects
In clinical trials involving the administration of 7918 doses of COMVAX (haemophilus b conjugate and hepatitis b vaccine) to 3561 healthy infants 6 weeks to 15 months of age, COMVAX (haemophilus b conjugate and hepatitis b vaccine) was generally well tolerated. In these studies, infants received COMVAX (haemophilus b conjugate and hepatitis b vaccine) with licensed pediatric vaccines (n=1745) or investigational vaccines (n=1816). Serious adverse experience data were available for all 3561 infants and non-serious adverse experience data were available for a subset of 1678 infants.
Pivotal Immunogenicity and Safety Study
In the pivotal, randomized, multicenter study, 882 infants were assigned in a 3:1 ratio to receive either COMVAX (haemophilus b conjugate and hepatitis b vaccine) or PedvaxHIB plus RECOMBIVAX HB at separate injection sites at 2, 4, and 12-15 months of age. Children may have also received routine pediatric immunizations. The children were monitored daily for five days after each injection for injection-site and systemic adverse experiences. During this time, adverse experiences in infants who received COMVAX (haemophilus b conjugate and hepatitis b vaccine) were generally similar in type and frequency to those observed in infants who received PedvaxHIB plus RECOMBIVAX HB.
The most frequently cited events were mild, transient signs and symptoms of inflammation at the injection site (i.e., pain/soreness, erythema, and swelling/induration), somnolence, and irritability, all of which were prompted for on report cards filled out by parents of vaccinated children. Table 3 summarizes the frequencies of injection-site and systemic adverse experiences within five days of vaccination that were reported among ≥ 1.0% of children in this pivotal trial.
Table 3: Local Reactions and Systemic Complaints Within 5
Days After Injection Reported to Occur in ≥ 1.0%† of Children Given
a 3-Dose Course of COMVAX (haemophilus b conjugate and hepatitis b vaccine) Compared to These Events in Children Given Concomitant
Injections of PedvaxHIB and RECOMBIVAX HB
|Event||Injection 1‡||Injection 2‡||Injection 3|
|COMVAX (N=660) %|| PedvaxHIB and RECOMBIVAX HB***
| COMVAX (haemophilus b conjugate and hepatitis b vaccine)
| PedvaxHIB and RECOMBIVAX HB***
| COMVAX (haemophilus b conjugate and hepatitis b vaccine)
| PedvaxHIB and RECOMBIVAX HB***
|Injection Site Reactions|
|Erythema ( > 1 in.)*||22.4 (2.7)||25.8 (2.7)||25.7 (1.4)||23.5 (3.3)||27.2 (3.0)||24.4 (1.6)|
|Swelling/Induration ( > 1 in.)*||27.6 (3.0)||33.5 (4.1)||30.4 (2.9)||31.0 (3.8)||27.2 (3.2)||29.5 (4.1)|
|unusual, high pitched*||10.6||8.6||6.7||2.3||2.9||3.6|
|not otherwise specified||2.3||2.3||1.4||2.3||0.7||1.6|
|prolonged ( > 4 hrs.)*||2.4||2.3||0.8||1.4||0.2||0|
|Fever (°F, rectal equiv.)**|
|Upper respiratory infection||0.5||0.5||1.1||0.9||1.3||0.5|
|† Overall frequency of
each event listed above is ≥ 1% even though the frequency after a given
dose may be < 1%.
‡ Most children received DTP and OPV concomitantly with the first two doses of COMVAX (haemophilus b conjugate and hepatitis b vaccine) or PedvaxHIB and RECOMBIVAX HB.
* Events prompted for on Vaccination Report Card given to parents/guardians of vaccinees.
** N for injections 1, 2, and 3 equals 655, 639, and 588, respectively, for COMVAX (haemophilus b conjugate and hepatitis b vaccine) ; N for injections 1, 2, and 3 equals 218, 213, and 187, respectively, for PedvaxHIB and RECOMBIVAX HB.
*** Injection site reactions for PedvaxHIB and RECOMBIVAX HB based on occurrence with either of the monovalent components.
Infants Previously Vaccinated with Hepatitis B Vaccine
In a group of infants (N=126) given a three-dose course of COMVAX (haemophilus b conjugate and hepatitis b vaccine) after previously receiving a dose of Hepatitis B Vaccine (Recombinant) at or shortly after birth, the type, frequency, and severity of adverse experiences did not appear to be greater than those observed in infants in the pivotal study who did not receive hepatitis B vaccine at birth.
Infants 6 Weeks to 15 Months of Age
In clinical trials, 3285 doses of COMVAX (haemophilus b conjugate and hepatitis b vaccine) were administered to 1678 infants who were monitored for injection-site and systemic adverse experiences from Days 0 to 5 after each injection of vaccine. Of these, 855 infants had safety data following vaccination at approximately 2 months of age, 836 infants at approximately 4 months of age and 1573 infants at 12 to 15 months of age. The most frequently reported adverse experiences ( ≥ 1% of subjects for at least one injection), without regard to causality are listed in decreasing order of frequency within each body system:
Injection Site Reactions: Pain/tenderness/soreness, swelling/induration, erythema; Body as a Whole: Fever; Digestive System: Anorexia, diarrhea, vomiting; Nervous System/Psychiatric: Irritability, somnolence, crying; Respiratory System: Upper respiratory infection, rhinorrhea, cough, rhinitis; Skin: Rash; Special Senses: Otitis media.
As with any vaccine, there is the possibility that broad use of COMVAX (haemophilus b conjugate and hepatitis b vaccine) could reveal adverse experiences not observed in clinical trials. The following additional adverse reactions have been reported with the use of the marketed vaccine.
Potential Adverse Effects
In addition, a variety of adverse effects have been reported with marketed use of either PedvaxHIB or RECOMBIVAX HB in infants and children through 71 months of age. These adverse effects are listed below.
Sterile injection-site abscess; pain at the injection site
Elevation of liver enzymes
Increased erythrocyte sedimentation rate
Bell's Palsy; Guillain-Barré Syndrome
Agitation; somnolence; irritability
Conjunctivitis; visual disturbances
Adverse Event Reporting
Patients, parents and guardians should be instructed to report any serious adverse reactions to their health-care provider who in turn should report such events to the U.S. Department of Health and Human Services through the Vaccine Adverse Event Reporting System (VAERS), 1-800-822-7967. The health-care provider should inform the parent or guardian of the National Vaccine Injury Compensation Program (NVICP), 1-800-338-2382.
Read the entire FDA prescribing information for Comvax (Haemophilus b Conjugate and Hepatitis B Vaccine) »
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Report Problems to the Food and Drug Administration
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