IS THE AGE OF ANTIBIOTICS OVER? Phage therapy Even though phage therapy is unlikely to be used as a standalone treatment, using phage therapy in combination with antibiotics, especially when acting synergistically, can revitalise our efforts in tackling MDR infections including against pathogens in the critical priority category as shown in the case presented by Schooley et al (2017). Concerns about immunogenicity and the release of bacterial endotoxins outlined in Table 1 were proven to be erroneous in this case. However, future clinical trials must be appropriately designed to ensure these potential harmful side effects can be detected to protect patient safety. In fact, all of the disadvantages of phage therapy outlined in Table 1 were overcome. The strength of phage therapy is the ability to personalise cocktails to the specific infection of the patient and even the development of resistance can be overcome by adjusting the formulations over time and can be exploited to benefit treatment. The huge biodiversity of bacteriophages in the environment is another key strength because of the enormous source from which to isolate, store, screen and select of phage that are clinically relevant to the infection. A key challenge ahead is developing comprehensive regulatory frameworks both globally and in individual countries within which the isolation, characterisation, storage, industrial production and experimental use of bacteriophages can be monitored and evaluated to accelerate the process of reaching patients in clinics.