Passive Antibody Administration (Immediate Immunity) as a Specific Defense Against Biological Weapons

Arturo Casadevall


Emerging Infectious Diseases. 2002;8(8) 

In This Article

Proposal for an Antibody-Based Defense Strategy

Stockpiling antibody-based reagents that can be rapidly administered to exposed populations would substantially reduce the threat of many biological agents by providing a means of conferring immediate immunity to susceptible persons. For persistent threats for which vaccines are available, this measure would provide additional time for immunization, as well as reducing the threat. Development of antibody-based therapies may reduce the attractiveness of biological warfare as a weapon of terror by providing antidotes to help neutralize the threat. An aggressor could attempt to defeat a passive antibody defense by engineering the agent to express antigenic changes, proteases, or antibody-binding proteins. However, in this arms race the advantage may favor the defender, since it is technologically easier to generate a new antibody effective against the changed agent than to engineer a pathogen or agent to enhance virulence. Antigenic changes by definition create new epitopes that can be targeted by other antibodies. Antibodies can also be engineered to resist proteolysis by altering the amino acid sequence to eliminate proteolytic sites. In fact, a neutralizing antibody preparation can likely be generated much faster than new biological agents can be developed. An example of the rapidity with which therapeutic antibodies can be developed comes from the 1905 epidemic of meningococcal meningitis in New York City, when Flexner generated an effective horse antiserum within months and used it to treat patients before the epidemic abated naturally.[94] Although this example is not applicable today, given regulations on the development of therapeutics, it provides a dramatic example of the concept that antibody therapies can be developed quickly. The development of antibody-based therapies relies on technology that can respond rapidly to new threats, whereas construction of new biological agents would almost certainly require considerable basic research and development. The same may not apply to new antimicrobial chemotherapy or vaccines, which often require substantially longer development times.


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