Antibodies are an effective part of the immune system. For bacterial infections, antibodies provide omnidirectional protection to host cells at almost every stage of the pathogenesis. Studies have found that an antibody-antibiotic conjugate (AAC), which combines the key properties of antibodies and antibiotics, has been shown to be effective against Staphylococcus aureus infection. Preclinical trials showed that AAC was much better in scavenging Staphylococcus aureus in infected mice than standard vancomycin (antibiotics). AAC has three components: the bactericidal antibiotic payload, the antibody that targets the delivery of the payload to the bacteria, and the linker that attaches the payload to the antibody. The three components in AAC are all playing pivotal roles in determining overall selectivity and specificity, degree of safety and mode of action.