Pertussis Vaccine

Types Of Pertussis Vaccines

Whole-Cell Pertussis Vaccine

• Contains killed Bordetella pertussis bacilli.
• Adsorbed on insoluble aluminum salts acting as adjuvants.
• Vaccine efficacy ranges from 61% to 89%.
• Elicits Th1 and Th17 biased immune responses.
• Associated with longer-lasting immunity and documented herd effect.
• Immunity wanes over 6-12 years requiring periodic boosters.

Acellular Pertussis Vaccine

• Developed primarily due to reactogenicity concerns of whole-cell preparations.
• Formulated with purified antigens including inactivated pertussis toxin, filamentous hemagglutinin, pertactin, and fimbriae.
• Multicomponent vaccines containing three or more antigens show higher efficacy compared to one or two component vaccines.
• Elicits Th2 biased immune responses.
• Associated with two-thirds reduction in minor and major adverse effects.
• Exhibits shorter duration of protection with faster waning.
• Lacks documented herd immunity effect.

Immunization Schedule And Administration

Primary And Booster Immunization

• Administered as 0.5 mL dose via intramuscular route.
• Preferred anatomical site is anterolateral aspect of thigh.
• Three primary doses given at 6, 10, and 14 weeks.
• First booster administered at 15-18 months.
• Second booster given at 4-6 years.
• Standard pertussis vaccines contraindicated beyond 7 years due to increased reactogenicity.

Catch-Up Immunization

• Children below 7 years require three doses at 0, 1, and 6 months.
• Second childhood booster omitted if last dose given beyond 4 years.

Adolescent And Maternal Immunization

• Reduced antigen vaccine administered as single dose at 10-12 years.
• Pregnant women require single dose during each pregnancy.
• Optimal administration timing during pregnancy is 27-36 weeks gestation.
• Maternal immunization protects vulnerable neonates via transplacental antibodies.

Adverse Effects And Contraindications

Adverse Effects

• Minor reactions include local pain, swelling, redness, fever, and fussiness.
• Serious events include hyperpyrexia, persistent crying, hypotonic-hyporesponsive episodes, and seizures.
• Incidence of systemic reactions decreases with subsequent doses.
• Incidence of local reactions increases with subsequent doses.

Contraindications And Precautions

• Absolute contraindication includes anaphylaxis following previous dose, encephalopathy within 7 days of previous dose.
• Progressive neurologic disease considered relative contraindication.
• Hyperpyrexia or hypotonic-hyporesponsive episodes considered precautions, not absolute contraindications.

Comparative Analysis Of Pertussis Vaccines