An anthrax vaccine that may be effective in as few as two doses is moving forward in development with the assistance of the U.S. Department of Health and Human Services’ (HHS) Office of the Assistant Secretary for Preparedness and Response (ASPR).

Anthrax/CDC
Anthrax/CDC

The five-year, $198.7 million contract between ASPR’s Biomedical Advanced Research and Development Authority (BARDA) and Emergent BioSolutions, headquartered in Gaithersburg, Maryland, funds the remaining development activities required for the company to apply to the U.S. Food and Drug Administration (FDA) for the vaccine’s licensure. This work includes a Phase 3 clinical study to determine the effectiveness of the vaccine candidate NuThrax, as well as a Phase 2 study to evaluate the vaccine’s safety and whether it interacts with an antibiotic administered as part of the routine treatment following anthrax exposure.

The contract also includes a provision regarding purchasing vaccine, as well as options to purchase vaccine in the future, for the Strategic National Stockpile (SNS). Prior to FDA licensure, the stockpiled vaccine could be used after an anthrax attack if authorized for emergency use by FDA.

“Fifteen years ago this month, anthrax was used as a weapon of domestic terrorism in the U.S. and its use remains a threat today,” said Dr. Richard Hatchett, acting director of BARDA.

“BARDA is sponsoring the development of NuThrax to help better protect our nation from this threat. This vaccine could provide protection in fewer doses than the anthrax vaccine currently available, potentially producing better health outcomes if it was needed during a public health emergency.”

NuThrax, also known as “AV7909” is enhanced with the adjuvant CPG 7909 to stimulate the immune system. Using adjuvants in a vaccine can reduce the amount of vaccine antigen needed to stimulate an immune response. Antigen is the component of the vaccine that stimulates the person’s immune system to protect against a bacterium. Needing less antigen in each dose of vaccine means more doses of vaccine could be made available.

Studies conducted to date with NuThrax indicate that two doses, administered 14 days apart, appear sufficient to stimulate a protective immune response against anthrax.

NuThrax is a modified formulation of the licensed vaccine BioThrax, an anthrax vaccine manufactured by Emergent that requires three doses to protect against anthrax. BioThrax is stored in the SNS.

Early development of NuThrax was sponsored by the National Institutes of Health’s (NIH) National Institute of Allergy and Infectious Diseases (NIAID), the Department of Defense, and BARDA. This early work included manufacturing process development, critical non-clinical studies, and completion of phase 1 and 2 clinical studies. The successful transition of AV7909 from early development under NIAID into advanced development under BARDA resulted from more than eight years of collaboration on the vaccine’s development between the two HHS agencies.

BARDA is coordinating with the CDC’s SNS to ensure our national preparedness for anthrax with the licensed anthrax vaccine, BioThrax. As this next generation anthrax vaccine matures, BARDA will synergize future anthrax vaccine procurements with the SNS.