What term describes the strength of a pathogen's ability to cause disease?

• A. Virulence
• B. Pathogenicity
• C. Immunogenicity
• D. Infectivity

Answer: (A)

Virulence describes the strength of a pathogen’s ability to cause disease, specifically how severe the illness can be once infection occurs. This differs from pathogenicity, which is the overall capacity to cause disease, regardless of how severe it is. Immunogenicity is the ability to trigger an immune response, and infectivity is the ability to establish infection. So virulence is the best term here because it captures how serious the disease can become.