Scientists and researchers have been making great strides in the fight against HIV/AIDS in recent years. In addition to developing vaccines that have shown great promise, there have even been some treatments that have been shown to eliminate the virus altogether. And it seems that with this latest development, which was published in Nature earlier this month, there might be a treatment that can double as a cure.
Developed at the Vaccine and Gene Therapy Institute at the Oregon Health and Science University (OHSU), this new vaccine proved successful in about fifty percent of the clinical subjects that were tested, and may be able to cure patients who are currently on anti-retroviral drugs. If successful, this could mean that a preventative vaccine and cure could come in the same package, thus eliminating HIV altogether.
Currently, anti-retroviral drugs and HIV vaccine typically aim at improving the immune response of the patient in the long term. However, they are limited in that they can never completely clear the virus from the body. In fact, aside from a very few exceptional cases, researchers have long believed that HIV/AIDS could only be contained, but not completely cured.
The OHSU team, led by Dr. Louis Picker, has been working on its own vaccine for the past 10 years. In that time, their research has shown that an immune response can in fact go beyond containment and systematically wipe the virus out of the body. As with most early vaccine candidates, the study revolves around SIV – a more aggressive virus than HIV that can replicate up to 100 times faster and, unchecked, can cause AIDS in only two years.
Picker and his research team created the vaccine by working with cytomegalovirus (CMV), another virus which is itself persistent, but doesn’t cause disease. In their initial tests, the vaccine was found to generate an immunoresponse very similar to that generated by CMV, where T-cells that can search and destroy target cells were created and remained in the system, consistently targeting SIV-infected cells until the virus was cleared from the body.
For the sake of their clinical trials, simian subjects were used that were infected by the HIV virus. When treated with the team’s vaccine, half of the subjects initially showed signs of infection, but those signs gradually receded before disappearing completely. This sets it apart from other vaccines which also generate an immunoresponse, but one which fades over time.
According to Dr. Picker, it is the permanency of the T-cells that allows the immunoresponse to be consistent and slowly eradicate the virus, eventually eliminating it completely from the system. Says Dr. Picker of their trials and the possibilities for the vaccine:
The virus got in, it infected some cells, moved about in various parts of the body, but it was subsequently cleared, so that by two or three years later the monkeys looked like normal monkeys. There’s no evidence, even with the most sensitive tests, of the SIV virus still being there... We might be able to use this vaccine either to prevent infection or, potentially, even to apply it to individuals who are already infected and on anti-retroviral therapy. It may help to clear their infections so ultimately they can go off the drugs.
Currently, Picker and his the team are trying to understand why some of the vaccinated animals did not respond positively, in the hopes of further increasing the efficacy of the vaccine. Once these trials are complete, it could be just a hop, skip and a jump to getting FDA approval and making the vaccine/cure available to the open market.
Imagine, if you will, a world where HIV/AIDS is on the decline, and analysts begin predicting how long it will take before it is eradicated entirely. At this rate, such a world may be just a few years away. For those working in the field of medicine, and those of us who are around to witness it all, it’s an exciting time to be alive!
And be sure to enioy this video from OHSU where Dr. Picker speak about their vaccine and the efforts to end HIV: