Anthrax Overview

Anthrax is a life-threatening disease caused by Bacillus anthracis, a bacterium commonly found in soil worldwide.  While most often associated with disease in farm animals, anthrax also poses a rare, but significant, health threat to humans who come in contact with the bacteria or their spores.  Humans can become infected by handling products from infected animals or by inhaling spores from infected animal products such as wool. People also can become infected with anthrax by eating undercooked meat from infected animals.

Due to the high stability and infectivity of anthrax spores, Anthrax can also be used as a biological weapon, and historically was weaponized by multiple countries in the twentieth century.  The impact of anthrax was demonstrated in 2001 when anthrax-laced letters were deliberately sent via the U.S. postal system and caused 22 reported cases of anthrax infection. 

The Centers for Disease Control and Prevention (CDC) classifies agents with recognized bioterrorism potential into three priority areas (A, B and C). Anthrax is classified as a Category A agent. Category A agents are those that:

  • can be easily disseminated or transmitted from person to person
  • result in high mortality rates and have the potential for major public health impact
  • might cause public panic and social disruption
  • require special action for public health preparedness.

If untreated, anthrax in all forms can progress rapidly to systemic disease and death. The fatality rate for patients with appropriately treated cutaneous anthrax is usually less than 1 percent, but for inhalation or gastrointestinal disease it can exceed 50 percent.  If diagnosed early in the course of infection, treatment with appropriate antibiotics is effective, especially if combined with vaccination.  This combined therapy is especially useful in a post-exposure setting following inhalation of spores which can re-establish infection after completion of antibiotic therapy.  A vaccine is available to provide protection for people in the military and others at high risk of infection including laboratory workers, and workers who may enter or re-enter contaminated areas. The currently available vaccine is given in a series of three doses over six months, and two additional boosting doses over the next year.

Our Vaccine Candidate

With support from the National Institute of Allergy and Infectious Diseases (NIAID), Division of Microbiology and Infectious Diseases (DMID), PaxVax is developing an oral vaccine to help protect against anthrax. NIAID is funding current GMP production, pre-clinical studies and Phase I studies. An Investigational New Drug application was filed with the FDA and a Phase I clinical trial was initiated in October 2013.