Alternative definition : NCI-GLOSS: The ability of a microorganism to cause damage to its host.; CDISC-GLOSS: The ability of an infectious agent to cause severe disease, measured
as the proportion of persons with the disease who become severely ill or die. [Principles
of Epidemiology in Public Health Practice, Third Edition. An Introduction to Applied
Epidemiology and Biostatistics, Glossary, CDC 2014] See also morbidity, vaccine.;