I saw both of these articles in the news one right after the other, and I had to share them with you folks. Obviously both efforts are in their respective infancies (even if we keep seeing incessant media-fueled suggestions that we may be on the verge of a breakthrough any day now), but the thought of humanity achieving the ability to defeat a deadly disease that only appeared about thirty years ago along with another one almost as old as life itself is always worthy of mention. To both borrow and slightly massage a quote from Richard Dawkins, this is the kind of thing that happens when people are not satisfied with not knowing the answers.
Phase 1 Clinical Trial (SAV CT 01) of the first and only preventative HIV vaccine based on a genetically modified killed whole virus (SAV001-H) has been successfully completed with no adverse effects in all [HIV positive, symptom free] patients, Western and Sumagen Canada Inc. announced.
In addition to safety evaluation, HIV-1 specific antibody detections have been performed throughout the follow up period. The antibody against p24 capsid antigen increased as much as 64-fold in some vaccines and antibody against gp120 surface antigen increased up to eight-fold after vaccination. The increased antibody titers were maintained during the 52 week study period. The boost antibody production in HIV-positive volunteer vaccines is highly encouraging, since it forecasts a success of the Phase 2 human clinical trial, which will measure the immune responses.
So. Is that all clear?
Basically, this means that the killed whole-virus vaccine has the ability to boost the body’s immune response to two specific proteins present in the virus itself. First, there’s HIV’s “docking mechanism”, the gp120 surface protein. The surfaces of our CD4+ T-cells, which assist in our active immune response, have a special affinity for this protein, making it especially easy for HIV to bond with them. Then, there’s the coating surrounding the virus’s genetic material after “docking”, the p24 capsid. Think of it as the container for the virus’s genetic material. Check out the picture below, which shows the step by step process of HIV attacking a CD4+ T-cell (click on it to make it slightly larger).
You can see gp120 as those orange lumps in the first three panels, and p24 as the red conical shape in the virus itself. With any hope, increased response to these two protein signatures will prove effective in stopping the disease. Phase 2 and 3 clinical trials are now being planned due to the success of this study.
Most therapeutic cancer vaccines available today require doctors to first remove the patient’s immune cells from the body, then reprogram them and reintroduce them back into the body. The new approach, which was first reported to eliminate tumors in mice in Science Translational Medicine in 2009, instead uses a small disk-like sponge about the size of a fingernail that is made from FDA-approved polymers. The sponge is implanted under the skin, and is designed to recruit and reprogram a patient’s own immune cells “on site,” instructing them to travel through the body, home in on cancer cells, then kill them.
Half of the mice treated with this method went into complete regression after just two doses. (No word on the others.) This is a novel approach to cancer treatment in two ways: the method and technology incorporated into attacking the disease, and the collaborative way in which it was done. By integrating schools of various disciplines available in one central location, it decreased the amount of time needed to get to Phase 1 trials. This implant is also thought to hold potential treatments for other forms of cancer as well, but there’s not much detail as to what other forms of cancer would respond to this approach.
As I said before, it’s way too early to tell if these new discoveries have the key to finally winning the fight against HIV or cancer, but in the world of science even our failures bring us one step closer to success.