An Overview of Diphtheria, Tetanus, and Pertussis Vaccines Manufactured by Sanofi Pasteur

I. Introduction

A. Diphtheria, Tetanus, and Pertussis: Etiology and Public Health Significance

Diphtheria, tetanus, and pertussis are serious infectious diseases that have historically imposed a significant burden on global public health. Understanding their etiology is crucial to appreciating the role of vaccination.

Diphtheria is an acute, toxin-mediated illness caused by toxigenic strains of the bacterium Corynebacterium diphtheriae. The bacterium typically colonizes the mucous membranes of the respiratory tract, leading to symptoms such as sore throat, fever, and the formation of a characteristic pseudomembrane, often in the pharynx or larynx. The primary virulence factor is diphtheria toxin, an exotoxin that inhibits protein synthesis in host cells, leading to tissue damage and potentially severe systemic complications, including myocarditis and neuropathy. Protection against diphtheria is primarily mediated by the presence of neutralizing antibodies against this toxin.[1] A serum diphtheria antitoxin level of

0.01 IU/mL is considered to confer some level of protection, while levels of ≥0.1 IU/mL are generally regarded as protective, and levels of 1.0 IU/mL are associated with long-term protection.[2]