It was a promising idea. Our infection-fighting immune system
hates cold viruses. If we put HIV proteins into a cold virus
and inject the engineered mix as a vaccine, the immune system should
fight off HIV like it does a cold. A vaccine like this may not stop
someone from becoming infected with HIV, but it might at least stop or
delay the progression to AIDS.
After some successful experiments in primates, a massive HIV vaccine
trial—the STEP trial sponsored by Merck—was started in 2004
with 3,000 volunteers worldwide, including 119 gay men in Seattle. The
trial, like several others, was based out of the HIV vaccine trials
unit in Seattle at the Fred Hutchinson Cancer Research Center. “This
was the first vaccine to get this far in quite a while,” noted Hunter
Kincaid, one of the Seattle volunteers.
In a scheduled peek at the raw data earlier this fall, it became
obvious that the vaccine couldn’t protect anyone from getting HIV (as
expected) nor reduce viral loads in those infected—a surprise big
enough to halt the vaccine injections. A deeper look at the data
revealed something much worse. People who had been infected with a
version of this cold virus before starting the trial seemed to have a
higher risk of getting HIV than those who had not been
vaccinated—a shock to everyone involved.
Now, after the trial has been abruptly stopped, Kincaid sounds more
skeptical. “I propose a new rule in science,” he says. “If you want to
test a new vaccine, you have to inject it into yourself as well; maybe
then they will do more preliminary research.”
Meanwhile, nearly 800 people involved in the vaccine trials are now
more vulnerable to HIV infection. On November 13, the leaders of the
study decided to tell volunteers if they received the vaccine and are
more susceptible to acquiring the
HIV virus, or if they received
the placebo. Kincaid is still waiting for test results to see which
group he is in.
The news that the vaccine may have backfired was reported in a
November 8 New York Times article “In Tests, AIDS Vaccine
Seemed to Increase Risk.” The article described the results as a
”puzzling and potentially troubling development” in a test of “one of
the most promising experimental AIDS vaccines to have been tested on
people.” Dr. Larry Corey, one of the scientific leaders of the trial,
was quoted as saying: “We did a beautiful experiment, but it definitely
was a disappointment.”
Kincaid sounds bitter about that assessment: “Personally, I think
calling it a beautiful study is a bit insensitive to those of us who
volunteered our time for their ‘beautiful study’ and were instead put
at increased risk of HIV infection.”
Kincaid, now a graduate student in Chicago, but at the time an
employee at Fred Hutchinson Cancer Research Center, joined the trial in 2005 because “volunteering to help out in the
creation of an HIV vaccine was a big deal. You volunteer your efforts
where you can, and they were having trouble recruiting enough people.”
Kincaid, only in his early 20s, came out after drug therapy could
combat HIV.
He says that HIV “is less of a lived fear for
my
generation.”
Another volunteer, W. F.—a physician in his mid-40s who was in
the placebo test group—is from a generation with a different
perspective on HIV. W. F. can acutely recount what HIV infection was
like before effective drugs became available. “My partner was down to
around 50 T-cells before the protease inhibitors came out—they
saved his life.” So, W. F.’s reasons for volunteering were both
intimate and rational. “I considered it my duty to participate, both as
someone with a personal interest in the disease and a professional
obligation to help people. The premise of
the vaccine was
interesting to me and I thought it held promise.”
W. F.’s reaction to the failure is mixed, though. He believes the
screwup has implications for the next large-scale anti-HIV vaccine
trial. “The fact that this vaccine may increase vulnerability to HIV
infection will scare away thousands of potential volunteers from any
new study. Worse, it’ll make it very hard to get any vaccine study
approved by a review board at any academic hospital, at least until the
mechanism of this failure
is fully understood. That
will take
years.”
W. F. is guardedly hopeful that enough people will volunteer for the
next, much smaller pilot trials. “It will ultimately take a few hundred
people who have a loved one who’s been hurt or killed by the virus to
step up and, yes, take a chance with their lives. They will be a little
harder to find next time around, but I still think they’re out there.”
Even with the shockingly bad results, he remains happy he participated
in this trial: “I considered it a privilege to be included in this
study, and I’d sign up for another one in a second if they’d have
me.”
Dr. Karen Mark, clinic director for the Seattle site, stands by the
trials. ”No one wants to hear this experimental HIV vaccine may have
increased people’s risk of infection,” she acknowledges. ”But the
people I’ve spoken with in the community realize the importance of
developing an HIV vaccine. The study worked the way it was supposed to,
getting the answer as quickly as possible. We’re not closing up shop
here.” Dr. Mark points out the failed STEP trial continues to be of
use. The blood samples collected along the way can help unravel what
exactly went wrong with this vaccine. If nothing else, all local
participants in this study received extensive counseling on how to
avoid HIV infection.
Hunter is still waiting to find out if he received the vaccine, and
if his blood had evidence for a prior infection with this cold virus.
He has a call in, but the answer hasn’t yet arrived. 
