Table 2.

Examples of weak and strong responses that can be associated with host damagea

EvaluationDescription of response
QuantitativeInsufficient number of immune effector cells and/or molecules to prevent host damageOverproduction of inflammatory mediators that result in tissue fibrosis or promote malignant transformation
Qualitative(i) Antibodies of specificities or isotype that do not mediate protection(i) Antigenic mimicry
(ii) Th2 responses instead of Th1 responses for pathogens that require Th1 responses for containmentb(ii) Eosinophilic inflammation in response to certain antigensc
(iii) Antibody-mediated enhancement of disease
  • a The appropriateness of weak and strong responses must be considered in the context of specific pathogens.

  • b Eosinophilic inflammatory responses may be useful for helminths but not certain fungi.

  • c Th2 responses are associated with strong antibody responses whereas Th1 responses are proinflammatory (15, 25). Th2 responses to pathogens that require strong cellular inflammatory responses for containment and eradication may result in chronic and progressive infections. However, it is noteworthy that this view may be an oversimplification of a very complex process (1).