The limitations of hyperimmune sera from immunized animals and human donors, such as lot-to-lot variability, risk of pathogen transmission and immunological complications have paved way for mAb therapeutics in infectious diseases. These drugs specifically target viral or bacterial proteins, interfering with the lifecycle and/or eliciting an immune response. Antibodies can also be used to neutralize toxins in bacterial infections.

Palivizumab (Synagis®) is the first mAb approved for the prevention of the severe respiratory disease caused by respiratory syncytial virus in high risk populations. This mAb targets the F-protein, and inhibits virus replication and also reduces the frequency of the condition in infants. Ibalizumab (Trogarzo®) is another promising mAb, which was approved in 2018 for the treatment of multidrug-resistant HIV-1 infection. This blocks the viral entry into the host CD4+ T cells by binding onto the CD4 receptors and thus it plays a role as a post-attachment inhibitor. Also, anti-endotoxins directed against the lipid A of gram-negative bacteria have shown favorable outcomes in treating sepsis. Currently, several other promising mAbs are under development to prevent infectious diseases caused by Ebola virus, hepatitis B and C, herpes simplex virus, among others.