Diphtheria / Pertussis / Tetanus

Approved Indications:

• Primary immunization against:
• Diphtheria
• Tetanus
• Pertussis (whooping cough)
• Booster immunization in children and adults:
• For continued protection after the primary DPT vaccine series
• Commonly given as DTaP (acellular pertussis) in children or Tdap in adolescents/adults
• Catch-up immunization:
• In individuals who are incompletely vaccinated or unvaccinated
• Includes specific recommendations for adolescents and adults, especially pregnant women and healthcare workers
• Maternal immunization:
• Tdap given during pregnancy (preferably between 27–36 weeks gestation) to provide passive immunity to the newborn against pertussis

Off-label / Clinically Accepted Uses:

• Outbreak control: Used in public health campaigns during pertussis outbreaks to limit disease transmission
• Post-exposure prophylaxis: Tetanus component may be used with or without tetanus immunoglobulin following injury

Route of Administration: Intramuscular (IM), preferably in the deltoid or anterolateral thigh

Routine Pediatric Immunization (DTaP):

• Primary series:
• 2 months
• 4 months
• 6 months
• First booster: 15–18 months
• Second booster: 4–6 years

Adolescent and Adult Immunization (Tdap):

• Single Tdap dose at age 11–12 years
• Td booster every 10 years thereafter
• Pregnancy: One Tdap dose during each pregnancy, ideally between 27–36 weeks gestation

Catch-up Schedules:

• Varies based on age and vaccination history
• Unvaccinated children/adults receive a series of 3 doses with minimum intervals of 4 weeks between doses 1 and 2, and 6 months between doses 2 and 3

Special Populations:

• Wound management (tetanus):
• Administer Td or Tdap in conjunction with tetanus immune globulin (TIG) if the patient is inadequately vaccinated or the wound is high-risk

Dose Volume:

• 0.5 mL per dose

The DPT vaccine is a combined immunization composed of inactivated bacterial toxins (toxoids) and inactivated pertussis components. The diphtheria and tetanus toxoids stimulate the immune system to produce neutralizing antibodies against the exotoxins of Corynebacterium diphtheriae and Clostridium tetani, respectively. The pertussis component, either whole-cell (DTwP) or acellular (DTaP), includes inactivated Bordetella pertussis antigens such as pertussis toxin, filamentous hemagglutinin, and pertactin. These antigens induce both humoral and cellular immunity, promoting immunologic memory that prevents infection or significantly reduces disease severity upon exposure.

Vaccines are biologic agents; traditional ADME pharmacokinetics do not apply. However:

• Onset of Immunity:
• Partial protection begins ~2 weeks after the first dose
• Full protective immunity requires completion of the primary series
• Duration of Protection:
• Varies by component
• Diphtheria and tetanus immunity lasts ~10 years
• Pertussis immunity wanes after ~4–6 years
• Booster requirement:
• Necessary to maintain immunity, especially for tetanus and pertussis

• Pregnancy:
• Tdap is safe and recommended during each pregnancy, ideally at 27–36 weeks gestation, to confer passive immunity to newborns
• No evidence of fetal harm
• Lactation:
• Safe during breastfeeding
• Does not affect milk production or pose risk to the infant

• Primary Class: Vaccine (Inactivated)
• Subtype: Toxoid and subunit vaccine
• DTaP: Diphtheria, tetanus toxoids, and acellular pertussis
• Tdap: Reduced diphtheria toxoid and acellular pertussis (for adolescents and adults)
• DTwP: Diphtheria, tetanus toxoids, and whole-cell pertussis (used in some developing countries)

• Known hypersensitivity to any component of the vaccine (e.g., aluminum, formaldehyde, latex)
• History of anaphylactic reaction to a previous DPT/DTaP/Tdap dose
• History of encephalopathy (e.g., coma, seizures, decreased consciousness) within 7 days of prior pertussis vaccine
• Progressive or unstable neurologic disorders (e.g., uncontrolled epilepsy) — defer until condition stabilizes

• High-risk groups:
• Infants with history of seizures or neurologic disorders should be monitored closely
• Adults with severe latex allergy (in latex-containing formulations)
• CNS adverse reactions:
• Rare cases of febrile seizures, hypotonic-hyporesponsive episodes
• Syncope risk:
• Adolescents may faint post-vaccination; observe for 15 minutes
• Guillain-Barré Syndrome (GBS):
• Rarely reported following tetanus-containing vaccines; evaluate risk-benefit in such patients
• Monitor for early signs of:
• Allergic reactions (e.g., urticaria, difficulty breathing)
• Persistent high fever, inconsolable crying (especially after DTaP in infants)

Common (≥10%):

• Local reactions: Pain, redness, swelling at injection site
• Systemic: Fever, fatigue, irritability (in infants), mild headache, malaise

Less Common:

• Nausea, vomiting, joint pain, chills

Serious and Rare:

• Anaphylaxis
• Seizures (febrile or afebrile)
• Hypotonic-hyporesponsive episodes
• High-pitched crying (>3 hours in infants)
• Guillain-Barré syndrome (very rare)

Onset: Side effects typically occur within 24–72 hours post-vaccination

• Immunosuppressants: May reduce vaccine efficacy; consider deferring routine vaccination during intense immunosuppression
• Live vaccines: Can be given concurrently with DPT at different sites using separate syringes
• Antipyretics (e.g., acetaminophen): Often used post-vaccination to manage fever but may slightly reduce immune response
• Blood products: No interaction as DPT is inactivated; not affected by immunoglobulin therapy

• WHO and CDC Guidelines: Tdap recommended during each pregnancy for maternal and neonatal pertussis protection
• Booster recommendations updated: Emphasis on adult Td booster every 10 years, with at least one dose being Tdap
• Shift toward acellular pertussis (DTaP, Tdap): In most countries due to lower adverse reaction rates compared to whole-cell formulations

• Temperature: Store at 2°C to 8°C (36°F to 46°F); do not freeze
• Protection: Keep in original packaging; protect from light
• Handling: Shake well before use to ensure uniform suspension
• Discard if frozen or if there are particulate matter or discoloration