Diphtheria – HealthyChildren.org

Diphtheria is a disease caused by Corynebacterium diphtheriae bacteria. The infection can be spread easily through sneezing and coughing. However, thanks to the widespread use of the vaccine against diphtheria (part of the combination diphtheria-tetanus-acellular pertussis [DTaP] vaccine), there are very few cases of diphtheria in the United States.

https://www.healthychildren.org/english/health-issues/vaccine-preventable-diseases/Pages/Diphtheria.aspx