Usage
This combination vaccine is prescribed for the prevention of diphtheria, tetanus, pertussis (whooping cough), and Haemophilus influenzae type b (Hib) infections. These are serious diseases that can cause life-threatening complications, especially in infants and young children. It is also used as a booster for adolescents and adults to protect against these same conditions.
- Pharmacological Classification: Vaccine (combined toxoid and bacterial subunit vaccine)
- Mechanism of Action: The vaccine stimulates the body’s immune system to produce antibodies against the toxins produced by the diphtheria and tetanus bacteria, as well as against the pertussis bacteria and Hib capsular polysaccharide. These antibodies provide active immunity and protection against these diseases.
Alternate Names
This combination vaccine may be referred to by abbreviations such as DTaP-Hib or DTwP-Hib, depending on whether acellular or whole-cell pertussis vaccine is included. Different combinations may include inactivated poliovirus and Hepatitis B vaccines as well (e.g. DTaP-HB-IPV-Hib).
Some examples of Brand Names includes Pentacel, Quadracel, Infanrix hexa or Hexacima. It may have different brand names in various countries.
How It Works
-
Pharmacodynamics: The vaccine components stimulate B-lymphocytes to produce specific antibodies against the respective antigens. This induces adaptive humoral immunity, protecting against future infections by the targeted pathogens.
-
Pharmacokinetics: The vaccine is administered intramuscularly (IM). The toxoids and antigens are slowly released from the injection site. The immune response develops over several weeks after each dose in the primary series, with booster doses further strengthening immunity. Elimination of vaccine components occurs through normal physiological processes.
-
Mode of Action: The diphtheria and tetanus toxoids are inactivated toxins that retain their ability to stimulate an immune response without causing disease. The pertussis component can be either whole-cell or acellular, each containing different antigens of the Bordetella pertussis bacteria. The Hib component consists of the bacterial capsular polysaccharide conjugated to a protein carrier, usually tetanus toxoid.
-
Elimination Pathways: The vaccine components are processed and eliminated through the normal metabolic processes of the body.
Dosage
Standard Dosage
Adults:
A single dose (0.5 mL) of Tdap is recommended as a booster every 10 years, and if never received, one time. Women are recommended to receive Tdap with every pregnancy, preferably between 27 and 36 weeks’ gestation.
Children:
The primary series typically consists of three doses of 0.5 mL each, given at 2, 4, and 6 months of age. Booster doses are recommended at 15-18 months and 4-6 years. It is typically given as part of the DTaP vaccination series.
Special Cases:
- Elderly Patients: Standard adult dosing applies.
- Patients with Renal Impairment: No specific dose adjustments needed.
- Patients with Hepatic Dysfunction: No specific dose adjustments needed.
- Patients with Comorbid Conditions: Vaccination may be deferred during moderate or severe acute illness. Specific precautions are necessary for individuals with a history of severe allergic reaction to a prior dose or vaccine component, those with a history of seizures following DTaP, or those with immunodeficiencies.
Clinical Use Cases The described vaccine is not used in those clinical settings but for prevention of infectious diseases.
Dosage Adjustments Dose adjustments are typically not required for this vaccine, except in cases of precautions or contraindications.
Side Effects
Common Side Effects:
- Local reactions at the injection site (pain, redness, swelling)
- Low-grade fever
- Irritability or fussiness
- Drowsiness
- Loss of appetite
Rare but Serious Side Effects:
- High fever (over 103°F)
- Seizures
- Inconsolable crying for 3 hours or more
- Allergic reactions (skin rash, itching, hives, swelling of the face, lips, or tongue, breathing problems)
- Encephalopathy
Long-Term Effects: No long-term adverse effects have been associated with this vaccine.
Adverse Drug Reactions (ADR): Anaphylaxis (rare).
Contraindications
- Severe allergic reaction to a previous dose or a vaccine component.
- Encephalopathy within 7 days of a prior dose of pertussis-containing vaccine (not attributable to another cause).
- Moderate to severe acute illness.
Drug Interactions
Immunosuppressive therapies (e.g., corticosteroids, chemotherapy, anti-rejection drugs) may reduce the effectiveness of the vaccine.
Pregnancy and Breastfeeding
Tdap is recommended during pregnancy, preferably between 27 and 36 weeks gestation. The vaccine is considered safe during breastfeeding.
Drug Profile Summary
- Mechanism of Action: Stimulates active immunity against diphtheria, tetanus, pertussis, and Hib by inducing antibody production.
- Side Effects: Common: Local reactions, low-grade fever, irritability. Rare: High fever, seizures, allergic reactions, encephalopathy.
- Contraindications: Severe allergy to a previous dose or vaccine component, encephalopathy after a prior pertussis-containing vaccine, and moderate to severe acute illness.
- Drug Interactions: Immunosuppressants.
- Pregnancy & Breastfeeding: Safe and recommended during pregnancy (Tdap); safe during breastfeeding.
- Dosage: Children: 0.5 mL IM at 2, 4, and 6 months, with boosters at 15-18 months and 4-6 years. Adults: 0.5 mL Tdap every 10 years. Pregnant women: Tdap between 27 and 36 weeks gestation.
- Monitoring Parameters: Observe for any signs of allergic reaction or other adverse events after vaccination.
Popular Combinations
DTaP-Hib is often combined with Inactivated Poliovirus Vaccine (IPV) and Hepatitis B Vaccine (HepB) to create a hexavalent vaccine. This reduces the number of injections required.
Precautions
- Defer vaccination in individuals with moderate to severe acute illness.
- Exercise caution in those with a history of seizures, Guillain-Barré Syndrome (GBS), or other neurological disorders.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Diphtheria Toxoid + Haemophilus Type B Conjugate Vaccine + Pertussis Toxoid + Tetanus Toxoid in children?
A: The primary series for children consists of three doses of 0.5 mL, given intramuscularly at 2, 4, and 6 months of age. Booster doses are given at 15-18 months and 4-6 years.
Q2: Can pregnant women receive this vaccine?
A: Pregnant women should receive Tdap, which includes tetanus, diphtheria, and acellular pertussis, ideally between 27 and 36 weeks’ gestation, regardless of their prior Tdap vaccination history.
Q3: What are the most common side effects?
A: The most common side effects are mild and include soreness, redness, and swelling at the injection site, low-grade fever, irritability, drowsiness, and loss of appetite.
Q4: What are the contraindications to this vaccine?
A: Contraindications include a severe allergic reaction to a previous dose or component of the vaccine, encephalopathy within 7 days of a previous pertussis-containing vaccine, and a moderate to severe acute illness.
Q5: How is the vaccine administered?
A: The vaccine is administered intramuscularly, typically in the anterolateral thigh for infants and young children, and the deltoid muscle for older children and adults.
Q6: Are there any drug interactions I should be aware of?
A: Immunosuppressive drugs like corticosteroids may reduce the effectiveness of the vaccine.
Q7: Is the vaccine safe during breastfeeding?
A: Yes, the vaccine is considered safe for both the breastfeeding mother and the infant.
Q8: Why are booster doses necessary?
A: Booster doses are needed to maintain immunity because the protection provided by the initial doses can wane over time.
Q9: What should I do if my patient experiences a serious reaction to the vaccine?
A: Seek immediate medical attention. Report serious adverse events to the appropriate reporting system.
Q10: Can this vaccine be given with other vaccines?
A: Yes, it can often be given concurrently with other vaccines, but typically at different injection sites.
