CAR-T is a developing treatment option for leukemia and lymphoma patients which utilizes a patients immune system to fight off cancer cells. It works drawing blood and extracting T-cells from a patient. The T-cells are then genetically modified to produce chimeric antigen receptors, or CARs, which will allow them to identify and attack the cancerous cells. Once T-cells are injected back into the body, they begin to multiply. The multiplication causes a violent reaction, but doctors have learned to control the shock. This technique creates a "living drug" which will live and continue to generate in patient's body.
This treatment has recently been approved by the FDA and has been showing promising results. There are a few problems, however. Firstly, the price is astronomical. Second, there is a high frequency of relapse in patients.
Scientists are attempting to solve both of these issues. To combat the massive price tag, a generic version of CAR-T cells are being tested. The generic cell can be mass produced, stored, and are not made from the cells of a patient. Removing the process of the unique CAR-T cells should drastically cut the price. To help fight the high relapse rate, scientists are experimenting with adding a second identifying CAR group to the T-cells. The second group will hopefully help the cells identify the cancer cells should the cancer reappear.
I am very eager to see if these techniques of modifying T-cells to fight disease can be applied to other diseases. I think it would be possible to create identification sites for, at least, bacterial infections. I think the main thing holding it back is cost and practicality. It is way easier and cheaper to give antibiotics than it is to create T-cells for less severe conditions.