In utilizing bacteriophages for medical therapy, there are a number of concerns that would need to be considered before a certain phage or phage cocktail is approved and used on live patients. Some of these concerns are concerns that can be tested and alleviated prior to the use in humans. If I were designing an approval protocol for phage therapies, the central test would be its ability to destroy the host bacteria without allowing for or causing the development of a resistant strain. With antibiotic resistant bacteria representing a cautionary tale against reckless unchecks therapy usage, I think it would be valuable to utilize bacteriophages that maintain their efficacy over time. This test ensures that the bacterial immune system can be overcome in a way that prevents or, at the very least, strongly mitigates, the possibility of a bacteriophage resistant bacteria developing in humans or in treatment centers, which are already working to tackle and control antibiotic resistance. The other concern I would like to see considered, though not necessarily tested against is the once-off nature of each individual therapy. When the immune system encounters, the bacteriophages, it will begin the generation of immune antibodies to the phages used to treat the infection. This prevents the use of the same phage drug with the same patient more than once. This means that a phage must either be able to completely clear the infection within a single run or two tight dosages or that a new phage or phage cocktail must be ready for a second dosage to clear any of the bacteria that weren’t cleared by the first one, for whatever reason. The human immune system is a complex system, and by introducing a second replicating, though not technically living, entity to treat a first, there is an immensely complex relationship playing out that needs to be studied and understood before irreparable changes are made. An approval process allows for that relationship to be understood for each individual treatment option before it is used.