[Haemophilus b Conjugate (Meningococcal Protein Conjugate) and Hepatitis B (Recombinant) Vaccine]
COMVAX [Haemophilus b Conjugate (Meningococcal Protein Conjugate) and Hepatitis B (Recombinant) Vaccine] is a sterile bivalent vaccine made of the antigenic components used in producing PedvaxHIB* [Haemophilus b Conjugate Vaccine (Meningococcal Protein Conjugate)] and RECOMBIVAX HB* [Hepatitis B Vaccine (Recombinant)]. These components are the Haemophilus influenzae type b capsular polysaccharide [polyribosylribitol phosphate (PRP)] that is covalently bound to an outer membrane protein complex (OMPC) of Neisseria meningitidis and hepatitis B surface antigen (HBsAg) from recombinant yeast cultures.
Haemophilus influenzae type b and Neisseria meningitidis serogroup B are grown in complex fermentation media. The primary ingredients of the phenol-inactivated fermentation medium for Haemophilus influenzae include an extract of yeast, nicotinamide adenine dinucleotide, hemin chloride, soy peptone, dextrose, and mineral salts and for Neisseria meningitidis include an extract of yeast, amino acids and mineral salts. The PRP is purified from the culture broth by purification procedures which include ethanol fractionation, enzyme digestion, phenol extraction and diafiltration. The OMPC from Neisseria meningitidis is purified by detergent extraction, ultracentrifugation, diafiltration and sterile filtration.
The PRP-OMPC conjugate is prepared by the chemical coupling of the highly purified PRP (polyribosylribitol phosphate) of Haemophilus influenzae type b (Haemophilus b, Ross strain) to an OMPC of the B11 strain of Neisseria meningitidis serogroup B. The coupling of the PRP to the OMPC is necessary for enhanced immunogenicity of the PRP. This coupling is confirmed by analysis of the components of the conjugate following chemical treatment which yields a unique amino acid. After conjugation, the aqueous bulk is then adsorbed onto an amorphous aluminum hydroxyphosphate sulfate adjuvant (previously referred to as aluminum hydroxide).
HBsAg is produced in recombinant yeast cells. A portion of the hepatitis B virus gene, coding for HBsAg, is cloned into yeast, and the vaccine for hepatitis B is produced from cultures of this recombinant yeast strain according to methods developed in the Merck Research Laboratories. The antigen is harvested and purified from fermentation cultures of a recombinant strain of the yeast Saccharomyces cerevisiae containing the gene for the adw subtype of HBsAg. The fermentation process involves growth of Saccharomyces cerevisiae on a complex fermentation medium which consists of an extract of yeast, soy peptone, dextrose, amino acids and mineral salts.
The HBsAg protein is released from the yeast cells by mechanical cell disruption and detergent extraction, and purified by a series of physical and chemical methods, which includes ion and hydrophobic chromatography, and diafiltration. The purified protein is treated in phosphate buffer with formaldehyde and then coprecipitated with alum (potassium aluminum sulfate) to form bulk vaccine adjuvanted with amorphous aluminum hydroxyphosphate sulfate. The vaccine contains no detectable yeast DNA, and 1% or less of the protein is of yeast origin.
The individual PRP-OMPC and HBsAg adjuvanted bulks are combined to produce COMVAX (haemophilus b conjugate and hepatitis b vaccine) . Each 0.5 mL dose of COMVAX (haemophilus b conjugate and hepatitis b vaccine) is formulated to contain 7.5 mcg PRP conjugated to approximately 125 mcg OMPC, 5 mcg HBsAg, approximately 225 mcg aluminum as amorphous aluminum hydroxyphosphate sulfate, and 35 mcg sodium borate (decahydrate) as a pH stabilizer, in 0.9% sodium chloride. The vaccine contains not more than 0.0004% (w/v) residual formaldehyde.
The potency of the PRP-OMPC component is measured by quantitating the polysaccharide concentration by an HPLC method. The potency of the HBsAg component is measured relative to a standard by an in vitro immunoassay.
The product contains no preservative.
COMVAX (haemophilus b conjugate and hepatitis b vaccine) is a sterile suspension for intramuscular injection.
What are the possible side effects of this vaccine (Comvax)?
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...
What are the precautions when taking haemophilus b conjugate and hepatitis b vaccine (Comvax)?
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...
Last reviewed on RxList: 3/4/2009
This monograph has been modified to include the generic and brand name in many instances.
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