The Scientist : NewsBlog Print: Vaccine, immunity no help in HIV
The Scientist: NewsBlog:
Vaccine, immunity no help in HIV
[Entry posted at 7th November 2007 09:42 PM GMT]

Initial analysis confirmed that an HIV vaccine from a halted trial does not prevent or quell infection, according to data presented today at the HIV Vaccine Trials Network meeting.

According to the press release from Merck, the investigational vaccine (V520) was not shown to be effective at preventing infection or reducing viral load in patients who became infected during the course of the trial. This analysis confirms the earlier findings on about half of the halted trial patients, released September 21.

Other preliminary analysis indicated that for patients with a pre-existing immunity to the vector carrying the HIV genes as a vaccine there were actually more cases of infection than with placebo.

Anthony Fauci, director of the National Institutes of Allergy and Infectious Disease, said in a statement that the data show no clear reason why the vaccine would not be effective and that these initial results were both "disappointing and puzzling."


 

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Not that puzzling
by Paul

[Comment posted 2007-11-09 06:11:10]
Am I the only one who is surprised at the surprise that has greeted the failure of this vaccine trial?

This evidence from monkey experiments was that this vaccine would not protect against infection but might help the immune system to keep viral levels low and prevent the onset of AIDS.

However five years ago (when human trials were already under way) tests on monkeys showed that the strategy used in this vaccine failed to protect monkeys against SIV and didn't give lasting protection to some monkeys infected with the considerably less virulent SHIV. This is thought to be because the immune reaction was simply not enough to blunt the viral onslaught. These results indicated that this vaccine strategy was very unlikely to be successsful in human trials.

"Monkey Puzzles" Science Vol.296 pp. 2325-2326 (2002)

In future perhaps it might be useful to test potential vaccines far more thoroughly in several different monkey models before proceeding to human trials.



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