Efficacy is not a concern at this point They wouldn't have start doing clinical testing if it wasn't showing efficacy, Shigamabs does bind to the toxins that E. Coli produces and it's independent of the E. Coli strains, it binds to the toxin of ANY strains.
The most important was to know if it was tolerated by humans and it is! The freaking placebo probably healed all by themselves which left us with no efficacy demonstration and it was expected due to small sample. I think those data will now attract more serious money as it is now quite a bit derisked. We'll see in the coming days. Next important step is the FDA's opinion and their OK and guidelines for the Phase III