Evaluation of Immunogenicity and Efficacy of Anthrax Vaccine Adsorbed for Postexposure Prophylaxis
- 1 July 2013
- journal article
- clinical trial
- Published by American Society for Microbiology in Clinical and Vaccine Immunology
- Vol. 20 (7), 1016-1026
- https://doi.org/10.1128/cvi.00099-13
Abstract
Antimicrobials administered postexposure can reduce the incidence or progression of anthrax disease, but they do not protect against the disease resulting from the germination of spores that may remain in the body after cessation of the antimicrobial regimen. Such additional protection may be achieved by postexposure vaccination; however, no anthrax vaccine is licensed for postexposure prophylaxis (PEP). In a rabbit PEP study, animals were subjected to lethal challenge with aerosolized Bacillus anthracis spores and then were treated with levofloxacin with or without concomitant intramuscular (i.m.) vaccination with anthrax vaccine adsorbed (AVA) (BioThrax; Emergent BioDefense Operations Lansing LLC, Lansing, MI), administered twice, 1 week apart. A significant increase in survival rates was observed among vaccinated animals compared to those treated with antibiotic alone. In preexposure prophylaxis studies in rabbits and nonhuman primates (NHPs), animals received two i.m. vaccinations 1 month apart and were challenged with aerosolized anthrax spores at day 70. Prechallenge toxin-neutralizing antibody (TNA) titers correlated with animal survival postchallenge and provided the means for deriving an antibody titer associated with a specific probability of survival in animals. In a clinical immunogenicity study, 82% of the subjects met or exceeded the prechallenge TNA value that was associated with a 70% probability of survival in rabbits and 88% probability of survival in NHPs, which was estimated based on the results of animal preexposure prophylaxis studies. The animal data provide initial information on protective antibody levels for anthrax, as well as support previous findings regarding the ability of AVA to provide added protection to B. anthracis -infected animals compared to antimicrobial treatment alone.Keywords
This publication has 25 references indexed in Scilit:
- Anthrax Vaccine–Induced Antibodies Provide Cross-Species Prediction of Survival to Aerosol ChallengeScience Translational Medicine, 2012
- A Three-Dose Intramuscular Injection Schedule of Anthrax Vaccine Adsorbed Generates Sustained Humoral and Cellular Immune Responses to Protective Antigen and Provides Long-Term Protection against Inhalation Anthrax in Rhesus MacaquesClinical and Vaccine Immunology, 2012
- Recombinant Protective Antigen Anthrax Vaccine Improves Survival when Administered as a Postexposure Prophylaxis Countermeasure with Antibiotic in the New Zealand White Rabbit Model of Inhalation AnthraxClinical and Vaccine Immunology, 2012
- Anthrax Toxin Receptor Drives Protective Antigen Oligomerization and Stabilizes the Heptameric and Octameric Oligomer by a Similar MechanismPLOS ONE, 2010
- A Short Course of Antibiotic Treatment Is Effective in Preventing Death from Experimental Inhalational Anthrax after Discontinuing AntibioticsThe Journal of Infectious Diseases, 2009
- Interlaboratory Comparison of Results of an Anthrax Lethal Toxin Neutralization Assay for Assessment of Functional Antibodies in Multiple SpeciesClinical and Vaccine Immunology, 2008
- Pharmacokinetic Considerations and Efficacy of Levofloxacin in an Inhalational Anthrax (Postexposure) Rhesus Monkey ModelAntimicrobial Agents and Chemotherapy, 2006
- Duration of protection of rabbits after vaccination with Bacillus anthracis recombinant protective antigen vaccineVaccine, 2006
- Anthrax hijacks host receptorNature, 2004
- Observations on the prophylaxis of experimental pulmonary anthrax in the monkeyEpidemiology and Infection, 1956