Recent progress in the development of anthrax vaccines.

Area of Science:

• Microbiology and Immunology
• Vaccine Development
• Biodefense

Background:

• Bacillus anthracis (B. anthracis) causes anthrax, a disease posing risks to both animals and humans.
• The potential use of B. anthracis as a biowarfare agent necessitates improved countermeasures.
• Current anthrax vaccines have limitations, including prolonged vaccination schedules and variable efficacy.

Purpose of the Study:

• To review recent advancements in anthrax prophylaxis and alternative countermeasures.
• To evaluate novel strategies for developing more effective anthrax vaccines and treatments.

Main Methods:

• Investigated various vaccine approaches, including those utilizing Protective Antigen (PA) and its domains.
• Explored alternative targets such as bacterial or plant-expressed PA, attenuated B. anthracis strains, spores, capsule, S-layer, and toxin components.
• Reviewed epitope-based vaccines, DNA vaccination, monoclonal antibodies, and therapeutic antibodies.

Main Results:

• Co-immunization with PA and domain I of lethal factor enhanced antibody responses.
• Epitope-based vaccines, specifically the loop neutralizing determinant, showed high protection (97%) upon challenge.
• DNA vaccination demonstrated promising, albeit variable, protection; monoclonal and therapeutic antibodies showed treatment applicability.

Conclusions:

• Significant progress has been made in developing alternative anthrax prophylaxis strategies.
• Novel immunogens, epitope-based vaccines, and antibody-based therapies offer promising avenues for improved anthrax prevention and treatment.
• Continued research is essential to overcome the limitations of existing anthrax countermeasures.