In recent years, there have been great advances in the field of phage research. Phages, as you might know, are ‘viruses’ that infect bacteria rather than animal or plant cells. Like viruses, they harness the genetic machinery of bacteria to reproduce and reinfect other cells. Unlike viruses, they can’t get you sick.
Since phages naturally prey upon bacteria, and typically infect specific bacterial species, they could presumably be used to treat infectious diseases like tuberculosis and tetanus. Phage therapy, though, is still a nascent field and much more research needs to be done before large-scale human testing can begin.
Still, phage therapy could offer a cheap and effective means of combatting disease. Since phages self-replicate, only a small sample would be needed to effectively manage a bacterial population. A study by Broxmeyer et al. (2002) showed that a small sample of phage-infected nonvirulent bacteria could be used as ‘Trojan horses’ to effectively deliver enough phage to eliminate cultures of tuberculosis. In addition, a study by Levin and Bull (2004) found that phage therapy for TB was highly effective when combined with multiple first-line antibiotics, and significantly decreased the rate of drug resistance.
For now, this is all a little sci-fi. In the future, though, phage therapy may emerge as a cheap and innovative way to combat unnecessary death by infection.