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BRIAN
DEER: THE VAXGEN EXPERIMENT Page 5
South
of VaxGen's offices, the next freeway exit gives
access to its powerhouse: Genentech. This is the
world's front-runner in medical biotechnology,
with seven licensed products, from human growth
hormones to a clot-buster, Activase. Twenty years
ago the company was all dreams and venture
capital; its few staff snipping and splicing
genes in a wasteland where shipyards had died.
Today, their ranks of Mercs and BMWs surround 26
buildings in biology's Silicon Valley.
Stopping
by from time to time are visitors from its
master, the druggernaut Hoffman-La Roche. With
twin headquarters in Basle and New Jersey, and
sales last year of SWf24.7bn (œ10.2bn), this
vitamins-to-Valium giant has the marketing muscle
should AidsVax come on stream. At its own labs,
Roche shuns the vaccine race, but with taxes
pledged to line-and-jab Africa and Asia
executives doodle in billions on the hope that
Francis pulls it off.
When
I flew to San Francisco to quiz Francis for this
story, Berman was ecstatic, in jeans and a check
shirt, over a new $1.4m vaccine facility. The
experiment produces a torrent of clinic samples;
each volunteer gives blood on 17 visits, and each
sample is split for tests. Giant freezers were
being installed to store bar-coded specimens.
There could be 400,000 in all. There's also a
$500,000 microbiology kit going in: DNA
sequencers, PCR machines, centrifuges and the
like. Soon he would direct 30 staff in 20 rooms.
He was like a seven-year-old on Christmas Day.
The
first thing that struck me was the push of the
spending, irrespective of scientific
achievements. Apart from all the investment so
far, Genentech had a 10,000-litre fermenting
tank, half full of New Jersey strain vaccine.
Nobody wanted that, worth $1m, flushed away, much
less the careers of its makers. The next thing I
noted was the standard of safety imposed on the
facility's construction. To handle a dangerous
pathogen in California, the brown-and-yellow
building, made from tipped-upright concrete
slabs, was stamped with certificates and permits
by the box load before the first plank was sawn.
It's both earthquake- and microbe-proof. And its
forests of copper pipes, air ducts and
bio-filters were tested to tolerances few
structures could endure.
But
while regulations make sure that the building is
safe, critics say that the product itself escapes
much rigorous scrutiny. With vaccines, any
problems often don't appear until mass-market
use, and such is the head of steam building up
behind Francis that sceptics think that if
AidsVax doesn't join the annals of useless shots,
it has the potential to join, say, a 1960s
measles vaccine that made the disease in those
infected worse.
What
worries some scientists is that because AidsVax
provokes antibodies to its own specific gp120
strains, there's a risk that it may actually
suppress the immune system's ability to combat
other strains. On this thinking (the principle is
sometimes called "deceptive
imprinting") even if the junkies were
protected against the New Jersey and Chiang Mai
strains, they might die more quickly if they get
infected with one of the countless other
mutations. "There's nothing new in
this," Dr Heinz Kohler, who has led
investigations at Kentucky University, said.
"It's just common sense."
At
Kansas University, researchers have found that
monkeys injected with gp120 and then a hybrid
kind of HIV had more of the virus in their blood
later on than infected animals which weren't
vaccinated. "The question is: will those
people who are vaccinated progress to Aids more
quickly if they become infected with HIV than
those who were not vaccinated at all?" Prof
McMichael at Oxford summarised. "We might
not know the answer for 10 years."
No
such problems were revealed in the preliminary
tests, but despite the importance of long-term
follow-up (recipients of the hepatitis B vaccine
that Francis worked on in the early 1980s have
been tracked for two decades), VaxGen no longer
monitors what has happened to the people who
received its product in the mid-1990s preliminary
tests. Francis argues that it makes more sense to
wait for the full-scale trial results.
This
apparent loss of data is surprising to some,
because history warns of the pitfalls of not
being thorough. In 1955, just one month after a
near-hysterical press conference in Michigan
launched polio vaccine, reports poured in to the
CDC of hundreds of children going down with the
disease, induced by the shots themselves.
President Dwight Eisenhower said that, because of
the "great pressure to bring this out",
scientists may have "short-cut a little
bit".
AidsVax
cannot give volunteers Aids, but there may be
something even more terrifying than the anxiety
that it might accelerate their disease if they
are later infected with HIV. Some scientists
think that, if it works at all, the product may
have a dangerous effect on the evolution of HIV.
Five years ago, Los Alamos scientists declared
that there was "no simple answer" as to
whether Aids could become contagious through
coughs and sneezes - and other researchers argue
that, in much the same way as a partial course of
antibiotics can promote resistant bacteria, so a
poorly-effective vaccine may promote more deadly
and infectious strains.
This
may sound like journalistic scare, but HIV's
best-understood RNA cousin is influenza virus,
which produces devastating mutations every 20 or
30 years. Hepatitis B virus, meanwhile, has
already produced mutant strains accepted as being
vaccine-induced. "When you use a vaccine,
you are introducing another selective
pressure," Dr Paul Ewald, professor of
biology at Amherst College, Massachusetts,
explained. "It could make the problem more
damaging, or less damaging, depending on the
antigen you use."
Researchers
told me that, compared with the potential risks
to volunteers, this doomsday scenario was
"unlikely". But with agencies standing
by to jab hundreds of millions of people, some
wondered if, for our species' safety,
"unlikely" was reassuring enough.
"My personal view," Dr Art Ammann,
president of the San Francisco-based Global
Strategy for HIV Prevention, and a former AidsVax
researcher, said, "is that we could face a
global nightmare."
*****
This
report is copyright, Brian Deer. Responses,
information and other feedback concerning this
resource on VaxGen and AidsVax and the
"world's first Aids vaccine" are
appreciated - via the briandeer.com homepage.
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