Interest in Strategic Treatment Interruptions (STIs)—for boosting the immune response to HIV decreasing toxicity and cost, and improving adherence—has skyrocketed in recent months; buy long-term research on their pros and cons is sorely missing. Durban brought us a few captivating though inconclusive results. Anthony Fauci, MD director of the National Institute of Allergy and Infectious Diseases (NIAID), presented very preliminary data on two approaches to what he insisted on dubbing Structured Intermittent Therapy (SIT)—as if this epidemic needed another confusing acronym. In the first, HAART given in an eight-weeks-four-weeks-off-cycle resulted in lower viral rebound (which could indicate improvement in the immune response to HIV) during the time-off at the end of the second or third SIT cycle in six out of seven patients (got that?). In the seventh patient, it produced increasing viral loads. CD4 counts did not fall (or rise) during the four to nine months of follow-up. And the activity of cytotoxic T cells (immune cells that destroy infected cells) increased in patients, but showed no change in four others. In the second approach, drugs given to seven people on a one-week-on, one-week-off schedule resulted in no viral rebound in six, and only a single detectable spike in the seventh. NIAID’s research on SITs continues, but no further results are in.

On a darker note, Andrew McNeil, MD, at the University of California at Davis. Presented data showing that the increased viral load in seven people who discontinued therapy resulted in suppression of the so-called lymphoproliferative response of the HIV-specific CD4 cells. This means that these cells, important players in the immune responses to HIV, did not increase in number in response to the presence of the virus during the time off drugs. If this data is confirmed, it doesn’t bode well for the potential, of SITs, STIs or whatever you call them to promote the body’s natural control of the virus.

So, the take-home message from Durban was mixed: You may ultimately be able to take a vacation from the drugs and all of their nasty side effects—perhaps long enough to make affordable even in the developing world—without the risking your CD4s. But you may never be able to discontinue your meds for good.