The virulence factor for diphtheria is an exotoxin named diphtheria exotoxin.

Virulence is the degree of pathogenicity within a types of parasites. The factors of virulence are the colonization of a niche in the host, immunoevasion, immunosuppression, entry and exit of cells and obtaining nutrition from the host.

i DONT know it myself

The virulence factor list include capsules, fimbriae, outer membrane proteins, techoic acids, protein A, and m protein. Virulence factors are factors that allow pathogens to avoid host defense mechanisms and adversely affect the host.

There are infinitely many things that do not contribute to the virulence of a pathogen. Elvis does not contribute to the virulence of a pathogen.