VaxGen's
AidsVax: "shot works in blacks"
claim hung on one Chicago heroin abuser
The
failure of AidsVax to prevent infection
with HIV - in clinical trial results
published in 2003 - triggered an intense
debate about the controversial product
and its manufacturer, VaxGen Inc of
Brisbane, California. Mail to this
website, maintained by Brian Deer, shows that
existing material on a VaxGen-AidsVax
index is read by significant
numbers. This page seeks to further
inform the discussion
Below
is material from two slides released by
VaxGen Inc on February 24 as part the
company's initial results presentation
from the phase III AidsVax trial. Both
slides - but particularly the second,
relating to black, Asian
and other subjects -
suggest a sudden rise in the number of
infections towards the end of the trial
(in the first slide apparently after
the trial) among subjects who received
placebo.
Although
the vaccine showed no statistically
significant efficacy (<4%),
in the full cohort of 5,009
subjects, the company claimed that it
appeared to have astounding efficacy
among blacks (>78%),
Asians (>68%) and
"others" (not white or
Hispanic) (>46%), who
together totalled 498
subjects. If the numbers of infections
among these minorities were statistically
significant, as VaxGen claimed, why would
they temporally bunch in the placebo
group? Critics say that, among other
curiosities in these graphs, the bunching
is suggestive of some confounding factor.
It
was later revealed that three and
possibly four of the infections among
placebo recipients were black women who,
extraordinarily, contracted HIV from the
same man in Chicago - and that the
company's widely-publicised claim of
efficacy among blacks rested on this
wholly bizarre circumstance. The Chicago
trial site attended by the women
recruited one third of the trial's
females, and most were African-American.
The site's co-ordinator, Parrie Graham,
was reported as saying that the male was
involved in the local drug scene.
Discussion
of the company's claims, such as on the Yahoo message
board, further raised the
question of whether the category
"black/Asian/other" even
represented any credible association
between such ethnic classifications, or
whether it had been devised by VaxGen
purely for the purpose of presenting the
statistics in the most
commercially-favorable light.
Three
versions of AidsVax trial
results, released in February
and March 2003, are also available.
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