FEATURE ARTICLE
The Growing Threat of Biological Weapons
The terrorist threat is very real, and it's about to get worse. Scientists should concern themselves before it's too late
Steven Block
Vaccination Woes
Anyone seeking to "improve" on wild-type anthrax might
begin by introducing antibiotic resistance in the form of a gene for
??-lactamase, which enzymatically destroys penicillin. Such a
transformation is rather straightforward, and similar to the kind of
thing done routinely today in molecular biology labs with
non-pathogenic organisms. Disease caused by a multi-drug- resistant
variant of anthrax would essentially be impossible to treat. Only
those with prior immunity, conferred by vaccination, would stand
much chance of survival.
Considerations such as this have helped to motivate the ongoing
campaign to vaccinate all 2.4 million U.S. active and reserve troops
against anthrax. The vaccination process, licensed by the Food and
Drug Administration (FDA), requires a six-dose regimen over an
18-month period. The modern vaccine is prepared from a cell-free
filtrate derived from an avirulent strain of B. anthracis.
By most accounts the current anthrax vaccine is as safe as, perhaps
safer than, typical vaccines, although every vaccine carries
residual risk. This is why the oral (Sabin) polio vaccine will soon
no longer be given to children in the U.S. Comprehensive vaccination
programs have reduced polio to such an extent that the risk
associated with receiving the oral dose, which leads to paralysis in
a minuscule fraction of cases, now outweighs the chance of getting
the disease itself.
Unfortunately, the U.S. military anthrax vaccination program has
been mired in controversy and scandal. Prior to the program, the
lone American company licensed by the FDA to produce anthrax vaccine
in the U.S. was the state-owned Michigan Biologics Products
Institute, and it was in danger of losing its license after
inspections raised questions about potency and sterility of the
vaccine. The troubled institute was bought out by Bioport, a company
apparently created solely to take over its assets and land the
lucrative government contract for the military. The most visible
corporate director of Bioport is Admiral William Crowe, former
chairman of the Joint Chiefs of Staff. Bioport thus became the
exclusive purveyor of anthrax vaccine and applied for FDA approval
of a Michigan plant to manufacture more. That approval is still at
least six months out. Meanwhile, existing inventories have dwindled,
and the military is running out of vaccine after administering fewer
than half a million doses (out of 14 million). As a result, they've
had to reduce monthly inoculations from 75,000 to 14,000 and suspend
injections for all but front-line troops considered at greatest risk.
In Senate hearings held in July 2000, Republican Senator Tim
Hutchison of Arkansas reacted to the situation as follows: "The
terms of the contract relief (between the Department of Defense and
Bioport) reduced the number of dosages to be produced by one half,
charged U.S. taxpayers almost three times as much as originally
negotiated, and provided Bioport an interest-free loan of almost $20
million. I am wondering who negotiated such a contract."
Issues of procurement and safety aside, the most disturbing aspect
of the anthrax-vaccination program is the unknown efficacy of the
new vaccine. A limited study, completed back in 1962 among mill
workers handling animal materials, demonstrated protection against
the cutaneous form of anthrax for an earlier version of vaccine.
However, no one is yet prepared to say whether the current
formulation will provide adequate immunity against acute inhalation
anthrax produced by a bioweapon. We may never really know, given the
obvious ethical considerations of experimenting with the vaccine. It
also seems possible that a strain of anthrax might be genetically
engineered to circumvent the immunity conferred by the present
vaccine. Does it therefore make sense to vaccinate all our military
personnel? Well, perhaps not all, but the risks to frontline troops
are very real, and the long interval required for the full
immunization schedule demands foresight. In the end, one is left to
make informed guesses.
The difficulties with the anthrax vaccine highlight an endemic
problem: The U.S. has precious little in the way of vaccine
production capabilities, and obtaining FDA approval for a new
vaccine protocol requires at least two years, generally more. The
vaccine industry faces serious issues analogous to the "orphan
drug" situation in the pharmaceutical industry. If a lot of
people are not dying of the disease, where is the market for the
product? And how does a manufacturer protect itself from ruinous
lawsuits? This is a topic that might be better addressed by the
public rather than the private sector.
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