Usage
This combination vaccine is prescribed for the prevention of diphtheria, tetanus, pertussis (whooping cough), hepatitis B, and Haemophilus influenzae type b (Hib) infections. It is intended for primary and booster vaccination in infants and young children. The individual components each target a specific pathogen.
Pharmacological Classification: Vaccine (combined). More specifically, it contains toxoids (inactivated toxins that induce immunity) for diphtheria and tetanus, inactivated pertussis antigens, hepatitis B surface antigen, and Hib capsular polysaccharide conjugated to tetanus toxoid.
Mechanism of Action: The vaccine stimulates an active immune response by mimicking a natural infection without causing the actual diseases. Each component of the vaccine triggers the production of specific antibodies against its target pathogen. These antibodies provide long-term protection against future infection. The aluminium hydroxide acts as an adjuvant, enhancing the immune response to the vaccine components.
Alternate Names
Several brand names exist depending upon the precise formulation (which may include additional antigens such as inactivated poliovirus or differ in the number of pertussis components). Examples include Hexaxim, Infanrix hexa, and Vaxelis.
How It Works
Pharmacodynamics: The vaccine components stimulate B lymphocytes to produce antibodies against diphtheria, tetanus, pertussis, hepatitis B, and Hib. These antibodies neutralize the toxins produced by diphtheria and tetanus bacteria, prevent the pertussis bacteria from adhering to the respiratory tract, and block the hepatitis B virus and Hib bacteria from infecting cells.
Pharmacokinetics: The toxoids and antigens are adsorbed onto aluminium hydroxide, which creates a depot at the injection site. The antigens are slowly released from this depot, allowing for a prolonged immune response. Antibody levels peak several weeks after vaccination. The exact pharmacokinetic parameters of each component can vary. Antibody levels can be measured to assess immune response.
Mode of Action: The vaccine components stimulate the humoral immune response by activating specific B cells through T cell-dependent and T cell-independent mechanisms. The aluminium hydroxide adjuvant promotes antigen presentation and uptake by antigen-presenting cells (APCs) like macrophages and dendritic cells, further amplifying the immune response. The specific mechanisms by which each antigen interacts with the immune system may differ.
Elimination: The vaccine components are gradually broken down and eliminated through normal physiological processes.
Dosage
Standard Dosage
Children:
The primary vaccination series generally consists of three doses of 0.5 mL, given at intervals of at least four weeks (e.g. at 2, 4, and 6 months of age, according to local recommendations). A booster dose is typically administered later (often between 15 and 18 months of age or at school entry). Different formulations of combined DTaP-HB-Hib (+/-IPV) vaccines are used in different jurisdictions and dosing may vary between these; always follow national guidelines.
Clinical Use Cases
The vaccine is specifically designed for primary and booster immunization of infants and children according to official immunization schedules and is not intended for other clinical settings.
Side Effects
Common Side Effects
- Pain, redness, and swelling at the injection site
- Fever
- Irritability
- Drowsiness
- Loss of appetite
Rare but Serious Side Effects
- Allergic reactions (e.g., anaphylaxis, hives, difficulty breathing)
- Seizures
- Hypotonic-hyporesponsive episode (HHE)
Contraindications
- Severe allergic reaction to a previous dose of the vaccine or any of its components
- Encephalopathy within 7 days of a previous dose of a pertussis-containing vaccine (for pertussis component only)
- Progressive neurological disorder (for pertussis component only)
Drug Interactions
Immunosuppressant medications or diseases may reduce the immune response to the vaccine. Consult the local guidelines and SmPC.
Pregnancy and Breastfeeding
This combined vaccine is not intended for use in pregnant or breastfeeding women.
Drug Profile Summary
- Mechanism of Action: Stimulates active immunity against diphtheria, tetanus, pertussis, hepatitis B, and Hib.
- Side Effects: Commonly injection site reactions, fever, irritability; rarely, serious allergic reactions or neurological events.
- Contraindications: Severe allergy to vaccine components, encephalopathy following previous pertussis vaccination, progressive neurological disorders.
- Drug Interactions: Immunosuppressants can reduce effectiveness.
- Pregnancy & Breastfeeding: Not recommended.
- Dosage: Three 0.5mL doses given at specified intervals in infancy; consult local guidelines.
Popular Combinations
This vaccine represents itself a combination of different antigens. Depending on the specific manufacturer, it may also include inactivated polio vaccine (IPV).
Precautions
- Postpone vaccination in individuals with moderate or severe acute illness.
- Monitor for allergic reactions.
- Pre-screening for bleeding disorders is advisable.
- Precautions specific to individual vaccine components should also be considered.
- Shaking the vial thoroughly before each dose is crucial to ensure uniform suspension of the vaccine components.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Aluminium Hydroxide + Diphtheria Toxoid + Hepatitis B Vaccine + Pertussis Toxoid + Tetanus Toxoid?
A: The primary series for infants typically includes three doses of 0.5 mL administered intramuscularly at intervals specified by national immunization schedules. Consult the Summary of Product Characteristics for the specific formulation.
Q2: Can this vaccine be given to premature infants?
A: Yes, premature infants can receive the vaccine according to the chronological age (from birth) following national immunization schedules.
Q3: What should I do if a dose is missed?
A: The missed dose should be given as soon as possible. It is not necessary to restart the entire series.
Q4: Can this vaccine be given with other vaccines?
A: Yes, it can generally be administered concurrently with other vaccines, but at different injection sites. Consult local immunization guidelines for specific recommendations.
Q5: What are the most common side effects?
A: Mild injection site reactions (pain, redness, swelling), fever, and irritability are common.
Q6: What are the contraindications to this vaccine?
A: Contraindications include a history of severe allergic reaction to any vaccine component, encephalopathy following a prior pertussis-containing vaccine, and progressive neurological disorders.
Q7: Is there a risk of developing autism from this vaccine?
A: No. Multiple studies have found no link between this vaccine and autism.
Q8: How long does the immunity from this vaccine last?
A: Protection from the vaccine wanes over time, therefore, booster doses are recommended to maintain immunity.
Q9. What is the route of administration for this vaccine?
A: Intramuscular (IM) administration, usually in the anterolateral thigh for infants and the deltoid muscle in older children.
