Supervised treatment interruptions fail to control HIV...( ector of the Partners AIDS Research Cen...),Health

To test this hypothesis the researchers did an open-label trial of STIs; they published data from a six-month follow-up in the Nature paper. "The key finding was that we were able to get at least transient control of the virus in all eight persons studied, and in five of eight the viral load was less than 500 copies (very low!) at the time of publication," explains Walker. However, at that point they did not know how long the protective effects would last.

The first evidence that protection was not complete came two years later when Walker's team reported a case of superinfection; one of the patients in the original experiment was infected with a second strain of HIV, even though the first virus was still well controlled. "This paper was important because it indicated that the amount of immunity might be enough for the person's own virus, but might not protect against closely related viruses circulating in the population," says Walker.

The PLoS Medicine study adds more concern since it shows that although most people can indeed transiently control their own virus, they do so for only a limited amount of time. "We expanded the study to 14 persons, and now have about five years of follow-up on some of the patients," says Walker. "Although we were able to use early treatment and structured treatment interruption to boost immunity and have 11 of 14 patients control their virus, most of the persons ultimately 'broke through,' meaning that they had a recurrence of viremia." At the present time the researchers do not know what causes the loss of viral control.

Walker and colleagues conclude that treatment interruptions should probably be avoided outside the setting of controlled clinical trials, whereas Douek goes a step further: "The stud
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25-Oct-2004