diphtheria toxoid/tetanus toxoid (dT, Td)

Introduction

No longer available

Indications

• active immunity against diphtheria & tetanus

Contraindications

• patients receiving immunosupressive agents
• prior anaphylactic, allergic or systemic reactions
• hypersensitivity to diphtheria or tetanus toxoid

Caution:

• pregnancy is not a contraindication
• waiting until the 2nd trimester is prudent
• patients with a severe local reaction (Arthus-type) should not be given another routine or emergency dose for 10 years

pregnancy-category C

safety in lactation ?

Dosage

• Infants & children (6 weeks to 1 year):
  • 3 0.5 mL doses at least 4 weeks apart
  • give reinforcing dose 6-12 months after 3rd injection
• Children 1-6 years:
  • 2 0.5 mL doses at least 4 weeks apart
  • give reinforcing dose 6-12 months after 2nd injection
  • if final dose given after 7th birthday, use adult preparation
  • Kinrix is combination vaccine for children 4-6 years of age
• Adults & children > 7 years of age:
  • primary immunization
    • 2 0.5 mL doses at least 4-6 weeks apart
    • give reinforcing dose 6-12 months after 2nd injection
  • boosters every 10 years
  • 0.5 mL SC after penetrating wound if > 5 years since last booster
• elderly: a single booster after age 49

Injection: (pediatric use):

• diphtheria 6.6-15 Lf units & tetanus 5-10 Lf units/0.5 mL 5 mL vials

Injection: (adult use):

• diphtheria 1.5-2 Lf units & tetanus 5-10 Lf units/0.5 mL 5 mL vials

Pharmacokinetics

elimination: liver

Adverse effects

• common (> 10%)
  • fretfulness
  • drowsiness
• less common (1-10%)
  • anorexia, vomiting, persistent crying
• uncommon (< 1%)
  • transient fever, convulsions (rare), tenderness, swelling, redness, pain, Arthus-type hypersensitivity reaction, tachycardia, hypotension, urticaria, pruritus

Drug interactions

• immunosuppressive agents decreased response to the vaccine

Laboratory

• Corynebacterium diphtheriae IgG in serum
• Clostridium tetani toxoid IgG in serum Clostridium tetani toxoid IgE in serum

Mechanism of action

• stimulates immunity to diphtheria & tetanus by eliciting specific antibodies for bacterial toxins

Notes

• a single dose of Tdap should be given to adults age >= 10 years to replace the next diphtheria-tetanus toxoid dT booster
• TdaP is acceptable alternative to dT
• a regression model estimates without further booster vaccination, 95% of the population would remain protected against tetanus for up to 72 years & against diphtheria for up to 42 years

More general terms

• vaccine combination

Additional terms

• acellular pertussis vaccine/diphtheria toxoid/poliovirus vaccine inactivated/tetanus toxoid (Quadracel, DTaP-IPV, Kinrix)
• diphtheria
• tetanus
• tetanus toxoid