Vaccines against anthrax based on recombinant protective antigen: problems and solutions

Area of Science:

• Biodefense
• Vaccinology
• Microbiology

Background:

• Anthrax, caused by Bacillus anthracis, poses a significant biodefense threat due to spore resilience and aerosolization potential.
• Inhalation anthrax is a severe, often fatal disease with limited existing countermeasures.
• The need for advanced vaccines against anthrax is driven by the risk of deliberate aerosol dissemination.

Purpose of the Study:

• To review challenges and achievements in developing vaccines based on anthrax recombinant protective antigen (rPA).
• To identify causes of rPA instability and explore solutions for improved vaccine design.
• To examine novel rPA formulations and combinations with other anthrax antigens.

Main Methods:

• Comprehensive literature search of scientific databases focusing on rPA instability and vaccine development.
• Analysis of studies on rPA expression, formulation strategies, and adjuvant combinations.
• Review of expert opinions on the efficacy and safety of rPA-based vaccines.

Main Results:

• Recombinant protective antigen (rPA) is a key component for defense against Bacillus anthracis.
• Subunit rPA vaccines demonstrate a favorable safety and protective profile.
• PA instability, exacerbated by aluminum adjuvants, remains a significant challenge.

Conclusions:

• Addressing PA instability through new adjuvant compositions, dry formulations, and engineered rPA variants is critical.
• Development of next-generation anthrax vaccines requires substantial research and effort.
• Optimizing rPA-based vaccines is essential for effective biodefense against anthrax.