EBS is the company supplying the current and only Anthrax vaccine to BARDA. Here is what is said in the Seeking Alpha article:
Competition and animal rule
Also based in Maryland, PharmAthene (PIP) has two anthrax products that will most likely be sharing a warehouse with Emergent's BioThrax. SparVax is under development for both pre- and post-exposure applications. It successfully completed a Phase 2 study on product that was manufactured in the UK, but must repeat the study with US manufactured product to satisfy the FDA. Valortim is a human monoclonal antibody intended for post anthrax exposure being developed in partnership with Bristol-Myers Squibb (BMY).
Before you dump your shares, it is important to understand a rule well highlighted in a recent article here. In 2002, the FDA issued the "Animal Rule" which allowed the approval of certain biologicals based on animal efficacy studies alone. You can't expose patients receiving placebo or vaccine to anthrax when you're certain it will kill the placebo group. Animal studies will have to suffice.
Luckily for Emergent, the "Animal Rule" also insists a variety of products for a given toxic agent be stockpiled, just to be on the safe side. If PharmAthene's anthrax products win approval, as they should, government warehouses will be storing its products alongside Energent's.