[rdedev]

The problem with phages is that our immune system can recognize them easily and flush them out of the body. It doesn't stick around long enough to do the work. It could work if the dose is massive or if the infection is localized to one specific area.

Btw this is what I learnt from reading a blog from someone who has worked with this stuff. I'm not a biologist and it's been a long time since I read that article so I can't seem to find it. So take the above stuff with a grain of salt

[krisoft]

> The problem with phages is that our immune system can recognize them easily and flush them out of the body.

The problem with phages is that they are finicky to administer. There is no "get this phage and it will kill all bacteria in and around you" treatment. They are specific. This of course has its own benefits too, but makes the process of administering harder.

With antibiotics the doctor comes to the conclusion that it is a bacterial infection. Then they write a prescription. And then you can buy the drug from any drug store. Antibiotics are largely shelf-stable and there is only a handful of different ones, so any drug store can keep all the major ones.

With phages the pipeline is more complicated.

You need to take a sample from the patient, you need to cultivate it, and then you need to check which phage or phage cocktail gets rid of that specific bacteria the best. That is a lot of lab work. Won't work at scale unless we automate it. And then there are questions like: How do they keep the phages healthy and happy? Are they working with a fixed selection of phages (a phage library if you will) or do they try phages based on the symptoms? Once they know which phage is the right one how does the patient get them? Can we stock them in our existing drug stores? Are they shelf-stable / can they be made shelf-stable? Which phages should the drug stores stock?

All of this can be of course answered and the problems ironed out. We put a man on the moon after all. We can do hard things if we want to. It is just a lot of faff.

[rdedev]

The reason I explained in my previous comment deals with the interaction between our body and the phage. A lot of drugs fail in this phase. What works in a cell culture need not work in the body. Even if you find the right phase for your infection it still might not work. All this might be solved with genetic engineering. But there a lot of work to do.

Also as an aside, physics is easier than biology. Once you figure out a solution that works, it always works in the future. The moon is not actively changing its orbit to survive. Bacteria or cancer for that matter always end up finding a way to overcome

[nextos]

This is not necessarily true. Our gut has trillions of bacteriophages. They are actually really useful as they keep bacterial populations under control.

Many bacteriophages are not immunogenic, i.e. our immune system will ignore them. Others are very immunogenic, and are actually used as vaccine platforms.

[rdedev]

Bacteriophages in the bloodstream is different from our gut. Our gut has a lot of bacteria too but the immune system rarely bothers with them till they start popping up outside the guy. We've coevolved with phages for a long time. So our immune system knows that they are mostly benign but don't like them hanging around the bloodstream and flush them out pretty quick