Table 2. Advantages and limitations of mAbs to treat infectious diseases.

Advantages	Disadvantages
Highly specific activity against the precise causative pathogen	Not useful for early empiric therapy before the pathogen is identified
Low risk of off-target effects and no effect on the microbiome	Must know the precise targeted pathogen or its toxins
Rapid molecular techniques for pathogen identity now becoming available	Rapid techniques for pathogen identity can be expensive and not widely available
Efficacy not dependent on antibiotic susceptibility; useful for MDR pathogens and can complement antibiotic therapy	Immune escape mutants can occur; multiple mAbs to same pathogen could help but will add additional costs
Long plasma half-life (10–21 days) allows a single dose treatment to save costs	Rare allergies, should they occur, could cause prolonged symptoms
Can be engineered with specific immune-modulatory properties (sialylation of carbohydrate moieties on Fc region)	Has to be delivered by parenteral route, no oral step down treatments
Costs of mAb production are coming down	Still very expensive
Generally well tolerated with low incidence of side effects or drug interactions	Must consider the possibility of AME

AME refers to paradoxical reactions were low affinity antibodies block assess of other defense molecules such as complement components to bind and neutralize the microbial target (47). This is a well described phenomenon with some viral and fungal infections and could occur with other pathogens. MDR, multidrug-resistant; mAbs, monoclonal antibodies; Fc, crystallizable fragment of immunoglobulin; AME, antibody-mediated enhancement.