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The anthrax
vaccine: Government's shot in the dark
By Sanjay Bhatt,
Palm Beach Post Staff Writer
Sunday, December 30, 2001
The federal
government has embarked on an experiment on humans to discover whether a
vaccine can protect civilians against future anthrax attacks.
For scientists to
reach conclusions about the vaccine's effectiveness after an
attack, however, anthrax must bring down more people.
A significant
number of the 3,000 people who turned down the vaccine must fall ill or
die from the disease to prove inoculation is effective. Or if the 58
civilians who have received the vaccine so far contract the disease
anyway, officials will know it doesn't work.
The experiment is
the latest illustration of how the nation is learning as it goes in the
war on terrorism, despite official pronouncements soon after Sept. 11
that the government was prepared for bioterrorism.
Three months after
the anthrax attacks, the federal Centers for Disease Control and
Prevention in Atlanta cannot offer clear recommendations for disease
prevention to the general public, or even to the people exposed to the
disease -- a stark reality that came into focus on Dec. 15, when the
nation's top medical minds convened in Washington, D.C., to debate moving
forward with the experiment.
"When
occasions like this occur, as devastating as they are, not only is it the
duty of the Public Health Service to protect the public . . . it's also
our duty to take advantage of the opportunity to figure out how to handle
such an emergency better in the future," said Dr. Charles Helms,
speaking for an advisory committee that shapes federal recommendations on
all vaccines.
The emergency's
scope: This year, five people have died from inhalational anthrax and six
others are recovering from it -- 11 cases in a few months, compared with
18 U.S. cases reported during the previous 100 years. Another 11 people
who contracted the skin form of anthrax are fine.
Officials have
determined all but two of this year's cases were infected through
anthrax-laced mail, a ubiquitous weapon that inflicted far more fear than
fatalities: More than 10,000 Americans endured weeks of the gut-wrenching
antibiotic Cipro to kill a potential infection, and suspicious mail closed
the U.S. Supreme Court and Senate buildings for record spans.
From the 22 anthrax
cases, this much seems clear -- though nothing is certain yet:
• Spores mixed with
certain chemical powders can be dispersed widely from a sealed or open
envelope and float through the air like a gas.
• Those who
contracted inhalational anthrax in 2001 were older adults, ranging from
age 43 to 94.
• Early treatment
of the disease with antibiotics and supportive care vastly improves the
chances of survival.
If antibiotics can
save those potentially infected with anthrax, why experiment on humans
with a vaccine?
For one, putting
thousands of people on antibiotics for months isn't a practical solution
because some cannot tolerate the side effects. And such a massive
antibiotic assault could cause the lethal germ to become resistant to
medicine's own atomic bomb.
In addition,
antibiotics attack only the reproductive form of the anthrax germ, thus
preventing it from producing toxins and damaging organs. Prior to this
"vegetative" form, the germ is in its dormant "spore"
form and not affected by antibiotics.
"We've never
done this before," explained Dr. Larry Bush, the Atlantis infectious
disease specialist who sounded the alarm in October on the anthrax
outbreak. "Now they're off prophylaxis (antibiotics), so we'll find
out if it works."
The concern is that
spores could lay silent in the lungs for months and not germinate -- thus
escaping the antibiotics.
With this in mind,
the foremost experts assembled on Dec. 15 in the auditorium of the
prestigious National Academy of Sciences to discuss the benefits and
risks of offering the vaccine for the first time to civilians attacked
with anthrax.
Inadequate data
All eyes were on
Dr. Jeffrey Koplan, a public health superstar who'd helped conquer
smallpox and control HIV. The tall and trim director of the CDC was
entering his fourth year on the job in October when the anthrax outbreak
occurred.
Facing those seated
that December morning, Koplan recognized there was "inadequate
data" to recommend the vaccine to victims, but he undercut critics
with a blunt disclaimer.
"Rarely do we
have all the information we need when we have to make public health
decisions," he said. What became clear that day was how shallow our
experts' knowledge base was and how its foundations were constantly
shifting.
The prime reason:
Federal research on anthrax as a weapon essentially came to a halt in
1969 as part of a non-proliferation pact signed with the Soviet Union.
The latter cheated on a massive scale, the United States would learn more
than a decade later.
The 1991 discovery,
after the Persian Gulf War, that Iraqi dictator Saddam Hussein had
produced weapons-grade anthrax resurrected federal support for research.
Scientists at the
December meeting appeared to have more studies to show the vaccine
improved the chances of surviving inhalational anthrax -- or that the
benefits outweighed the risks.
The main benefit of
vaccination: training the body's immune system to recognize the germ's
lethal toxins and fight off an infection. The vaccine is licensed by the
U.S. Food and Drug Administration for use only before anthrax exposure.
The main risk:
exposing a diverse group of civilians, some with chronic illnesses, to a
vaccine that has been tested mainly in healthy soldiers. The rate of
allergic reactions and potentially more serious side effects could be
higher.
The decision on
whether the benefit outweighs the risk hinged on the likelihood that
anthrax spores survive in the body past the 60 days of antibiotics.
On this question,
scant animal research since the 1940s suggests that anthrax spores might
survive in the human lungs for long periods before being destroyed or
causing infection.
"We don't know
why it's cleared or how it's cleared, but we know its dormancy can be for
long periods of time," said Col. Art Friedlander of the U.S. Army
Medical Research Institute of Infectious Diseases.
In one of the early
monkey studies, 15 percent to 20 percent of the initial dose of spores
remained 42 days after exposure. At 75 days, 1 percent of the spores were
still present, and at the 100th day, trace amounts.
Dr. D.A. Henderson,
who now heads the U.S. Office of Public Health Preparedness, found in
studies of monkeys that if antibiotics were discontinued 20 days after
anthrax exposure, they died. Those monkeys that received penicillin and
vaccination after being exposed survived.
In a key 1966
study, viable spores were found in all "apparently healthy"
monkeys in the two-month period following exposure, said Dr. Greg Martin,
chief of infectious diseases at Walter Reed Army Medical Center in
Washington, D.C. One monkey that was taken off antibiotics died 98 days
after exposure.
"So all these
things were somewhat disconcerting to us, that possibly some of our
highly exposed people may develop inhalation anthrax down the line,"
Martin said.
While the monkey is
considered the best model for studying disease in humans, the studies are
not perfectly applicable because they were done using wet aerosols, not
the dry powders seen in letters sent to two senators and a news network
anchor.
"If that has
any effect on the time to germination, it probably prolongs it,"
Phil Russell of the U.S. Department of Health and Human Services said of
the dry powder.
On the other hand,
no more inhalational anthrax cases have been reported nationwide since
Nov. 21, despite the fact that large numbers of people exposed to the
germ didn't stick to their 60-day antibiotics regimen.
Also, no anthrax
cases were reported beyond 43 days after people were exposed in 1979 to a
cloud of anthrax spores from a Russian bioweapons factory, the largest
inhalational anthrax outbreak in history.
"Knowing that
there is probably not great risk of those individuals getting inhalation
anthrax, I probably would have a great deal of difficulty recommending to
an individual patient that they take the vaccine at this point,"
said Dr. Larry Siegel of the Washington, D.C., health department.
Then there's a U.S.
military study, done after the Gulf War, that offers mixed
interpretations.
Sixty monkeys were
exposed to low doses of anthrax. Some were given no treatment, others
various kinds of antibiotics only, and the rest antibiotics and two doses
of vaccine. The treatments, which included ciprofloxacin and doxycycline,
were stopped at 30 days.
None of the nine
monkeys that had taken doxycycline and vaccine succumbed to anthrax. But
five monkeys who received only antibiotics died six to 28 days after the
drugs were stopped. The differences between the vaccinated and
unvaccinated monkeys weren't statistically significant. But the disparity
clearly worried scientists at the meeting.
Three-and-a-half
months after the initial exposure, researchers sprayed the survivors and
some fresh monkeys with 50 times the average lethal anthrax dose. Only
the monkeys that had taken vaccine survived.
"One reason to
offer vaccine to the postal workers is that there is a continuing threat
of anthrax coming through the mail," Siegel said.
Diminished
public confidence
While the
government's experiment meets ethics guidelines for human trials, public
health officials knew the vaccine would be a tough sell because of
diminished public confidence in the CDC. The agency made several initial
assurances concerning anthrax that later proved wrong: It said that
spores couldn't infect people from inside an envelope. It also said that
blood tests would help pinpoint who was exposed.
Moreover, the
federal government has a history of conducting human trials on unknowing
participants, including radiation tests on people in the 1950s and the
Tuskegee Syphilis Study on black men from 1932 to 1972 in Macon County,
Ala.
The purpose of the
Tuskegee study, which was supervised by the CDC, was to see how the
syphilis germ destroys the body. In the late stages, the germ can cause
paralysis, gradual blindness and dementia. According to the Tuskegee
University's Center for Bioethics in Research & Health Care, the men
who enrolled in the study were never told they had the disease.
Government officials informed them they had "bad blood" and
that they would be treated at no cost. Instead, not only were they given
placebos, but they were systematically prevented from having penicillin
even after it was shown to be a quick and effective cure for syphilis in
the 1940s. For this, the poor, rural and uneducated men received hot
meals on the days scientists visited, free rides to the hospital
affiliated with Tuskegee Institute and $50 for burial insurance.
Now, some people
have doubts about what motivated the government's anthrax vaccine study.
"With the
Cipro we felt like lab rats," said J.D. Robinson, a reporter for
AMI's tabloid The Globe, who chose not to take the vaccine or any more antibiotics.
"They don't even know all the side effects of this vaccine."
Those like Robinson
who have stopped taking antibiotics will not be tracked by the CDC but
have been given emergency numbers to call if they fall sick. Those who
take the vaccine in three doses over a month will be monitored for two
years, CDC officials said.
It could take that
long for the jigsaw puzzle dumped on America in October to be put
together and understood.
Nagging
questions
Other unanswered
questions include whether a weaponized anthrax letter can contaminate
other pieces of mail during the sorting process to create a broader
threat to the public beyond its addressed recipient.
Cross-contamination
has emerged as the leading theory for how 94-year-old Ottilie Lundgren of
Oxford, Conn., became fatally infected. She was not a mail, government or
media worker, and investigators didn't find spores in her home.
Once tainted
letters are delivered, it's unclear what it takes to make the spores
airborne again. Lundgren reportedly tore her mail in half before throwing
it away, CDC officials say, and that act could have sent spores into the
air.
Another question is
how to identify those exposed before they become ill and diagnose them
correctly in the early stage. Nasal swabs can miss people who were
exposed, and blood tests done on Boca Raton's American Media Inc.
employees haven't made sense, officials say.
And the early stage
of the disease can be confused with the flu because no definitive tests
are available. That's why one infected postal worker in Washington, D.C.,
area was sent home from a hospital a day before he died.
While antibiotics
kill the anthrax germ, there is no approved treatment to counteract the
toxin produced by the germ. That's why those in the disease's late stage
seldom recover. Circulating toxin leaves damage in its wake. Blood
pressure drops rapidly. The organs become swollen and starved of oxygen.
Near the end of the
December meeting, someone also complained that "monkeys are in
extremely short supply." The nation's experts adjourned at 1:30 p.m.
that Saturday.
"I think this
is a perfect way to summarize our deliberations today," said Dr.
Julie Gerberding, a top CDC official. "We are listening and we are
learning."
Three days later,
the CDC announced it would offer the vaccine to those who handled
anthrax-positive letters, who worked in a place where someone contracted
the disease or who worked somewhere that was heavily contaminated.
Forty-eight hours later, 48 Capitol Hill staffers were the first victims
to receive the vaccine, prompting an outcry from Florida public health
officials, whose patients had stopped taking antibiotics before the
Congressional staff.
Six postal workers
from the Washington, D.C., sorting plant also chose to be inoculated. They
and other candidates in the Northeast will have until Jan. 7 to make a
final decision about taking the vaccine.
But the 1,000
people connected with American Media Inc.'s Boca Raton headquarters would
receive only a one-time offer. They had to take the first dose within two
weeks of discontinuing antibiotics for the vaccine to be effective, CDC
officials said. And they received the offer a week after the research
meeting -- the weekend before Christmas.
Health officials
expected some 200 people to come to a Delray Beach clinic for counseling,
but only 62 showed up. Thirty-eight opted to take 40 more days of
antibiotics.
Only four decided
to take the vaccine.
sanjay_bhatt@pbpost.com
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