Did Shots Cause Hepatitis C? Officials Downplay Concerns
(Star Tribune)
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Star Tribune intern Andrew Atkins contributed to this report.
Copyright 1997 Star Tribune.
Greg Gordon; Staff Writer, Did
shots cause hepatitis C?
Officials downplay concerns.,
Star Tribune, 07-28-1997, pp 01A
When
a test was developed three years ago to detect the potentially deadly
virus hepatitis C, researchers at the Food and Drug Administration (FDA)
made a disturbing discovery. They found the genetic fingerprint of
the virus in batches of a blood-plasma product that has been used for
decades to inoculate U.S. soldiers and
other Americans against hepatitis A and B before they travel to Third
World nations.
Officials
at the FDA and the Centers for Disease Control and Prevention (CDC) say
that despite the finding, there is no need to worry about the safety of
those inoculations. Even if the virus got into the inoculants, the
officials contend, its genes were damaged during the manufacturing process
or otherwise neutralized.
Some
scientists aren't so sure.
And
FDA and CDC officials acknowledge that there has been no definitive
research on whether the inoculants could have transmitted hepatitis C, a
disease estimated to have infected 3.9 million Americans.
A
number of public-health experts say more studies are needed to prove that
the inoculations were safe and didn't put soldiers and travelers at risk
of contracting the slow-moving, blood-borne virus that is a leading cause
of liver disease.
In
a recent report, the General Accounting Office quoted an anonymous FDA
official as saying that although there are no known instances in which the
shots have transmitted the disease, "this is a very scary
situation."
Last
year, after the FDA ordered that immune globulin inoculants undergo
testing for hepatitis C as a "fail-safe measure," all private
manufacturers pulled their products from the market. Some of these
companies, including Pennsylvania-based Centeon, which was the military's
principal supplier, said they soon will seek FDA approval to add steps to
their production processes that inactivate the virus. The pharmaceutical
industry also recently developed a vaccine for hepatitis A that eliminates
much of the need for the immune globulin.
But
Sen. Richard Shelby, R-Ala., has asked the Pentagon to look further into
the possibility that the inoculants may have spread the disease.
In
a letter to the Defense Department in May, Shelby said that since the
inoculants weren't virally inactivated, "it is possible that military
personnel sent to Somalia, Panama, Haiti, the Persian Gulf and other
theaters were exposed to hepatitis C through the . .injections."
In
a 1993 Army study, blood tests were taken on 513 soldiers before and six
months after they were inoculated with immune globulin and deployed in
Somalia. The study found that none was infected by the shots, said
coauthor James Writer, an epidemiologist at the Walter Reed Army Institute
of Research. But Writer and other experts said the study's methodology
wouldn't pass scientific muster, in part because it wasn't known whether
the soldiers received tainted inoculants.
After
a different immune globulin product was found to have transmitted the
disease in 1994, the CDC tested about 100 civilian travelers who had
received immune globulin shots from lots known to contain hepatitis C
genes. None was infected, said Jay Epstein, the FDA's director of blood
research and review, who vouches for the inoculants' safety.
Dr.
John Penner, a Michigan State University hematologist who sits on the
FDA's Advisory Committee on Blood Safety and Availability, said he cannot
recall "any really good studies" on whether immune globulin
shots can transmit hepatitis C.
"It
probably needs to be looked at . . . more carefully," he said.
However, if low amounts of the virus in the products infected a small
percentage of people, "we might have a hard time uncovering it,"
he said.
Former
Surgeon General C. Everett Koop said more research is needed on all
possible transmission routes for hepatitis C - including immune globulin
inoculations.
A
Mystery
The
inoculants have been considered a possible suspect in part because most
scientists view the virus' spread as somewhat of a mystery. As many as 44
percent of its victims typically report no risk factors - such as having
had a blood transfusion, having shared intravenous needles or having held
a health-care job.
Also,
until recently, it has been easy to contaminate immune globulins. It takes
10,000 to 25,000 blood donations to produce one dose, which can be tainted
by a single infected donor. After tests to detect hepatitis C were
developed in 1990, manufacturers began screening donors for the virus.
Federal
health officials and spokesmen for makers of immune globulin inoculants
say that, despite these factors, the products always have been safe
because the manufacturing process kills the virus.
"Intramuscular
immune globulin is safe and has never transmitted hepatitis C or any other
infectious disease as licensed in the United States," said Miriam
Alter, the CDC's chief hepatitis epidemiologist.
She
said that although many victims reported having no risk factors, follow-up
interviews with a sample group established that all but 1 percent of them
had "high-risk drug and sexual behaviors." Alter said her agency
had "miscommunicated" by failing to publicize that follow-up
data, thus leaving the impression that the disease spreads in unknown
ways.
Other
scientists, even federal officials who say that immune globulins are safe,
are skeptical of such sweeping conclusions. Edward Tabor, director of the
FDA's Division of Transfusion-Transmitted Diseases, said he is "a
little bothered" by the deduction that anyone who has the virus and
has used drugs got it from an infected needle. In many cases, he said,
"you're talking about somebody who experimented with drugs
once."
Centeon
spokesman Jimmy Hendricks said that since 1992, 11 people have contended
that the company's globulin gave them hepatitis C and that FDA and company
inquiries exonerated the product in each case.
Not
Tested
If immune globulin inoculants
carried the hepatitis C virus in the past, the military would be a good
place to look for victims. The Pentagon ordered 481,000 doses of the
inoculants from 1992 to 1996; the number of those doses actually
administered was unavailable.
Capt.
David Trump, an official of the Defense Department's Office of Health
Affairs, said that troops aren't routinely tested for hepatitis C and that
no statistics on the number of infected soldiers exist. But, he said:
"We really don't have any evidence that the military population in
general is different from the civilian population when it comes to
hepatitis C infection."
Army
epidemiologist Writer said a 1992 study of random blood samples from
15,124 active duty personnel found that 1.3 percent tested positive for
hepatitis C - below the national infection rate of 1.5 percent. Rider
didn't know how many of those tested had received globulin shots.
Shelby,
a member of the Senate defense appropriations subcommittee, has inserted
language in this year's appropriations bill calling for the Defense
Department to study the rate of hepatitis C among personnel who received
globulin inoculations.
At
a warehouse in Rockville, Md., the department has stored millions of
frozen blood samples taken during physical examinations of Army, Navy and
Marine Corps personnel since the mid-1980s to test troops for AIDS. Air
Force blood samples were added recently.
Former
Surgeon General Koop said the military should begin screening troops for
hepatitis C. "You've got a demon on your hands," he said.
"You'd better find out where that's coming from if you can."
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Immune serums (immune globulin)
are starter material for vaccines
that provide passive immunity to infectious disease. Treatment is recommended for
Rh-negative children and women of
childbearing age who received
Rh-positive red cell containing
components
The protection will be of rapid
onset, but of short duration (1-3 months). Immune sera are obtained from pooled
human plasma of either general population donors or hyperimmunized donors. It
may be administered either by intravenous (IV) or intramuscular (IM) injection. Intramuscular immunoglobulin
preparations are prepared according to the Cohn fractionation
process, which separates the fraction containing antibodies that
neutralize various infectious agents. The resulting preparations are
highly concentrated (16% in solution and containing 160 mg of
protein/mL).
Other manufacturing procedures do not ensure the same safety.
Cohn's method number 6 was particularly amenable to
largescale use. This method results in five major fractions:
fraction I (fibrinogen), fractions II and III (gamma globulins),
fraction IV (alpha and beta globulins), and fraction V (albumin). As
expected, differences in fractionation and purification processes
between manufacturers exist ...
However, the role of partitioning of
viruses cannot be taken in
isolation; when antibodies to HCV
were removed following the
introduction of screening, the
amount of recoverable HCV-RNA in the
various Cohn fractions changed
dramatically as a result of the
virus no longer being complexed with antibody.
28 ...As Cohn–Oncley
fractionation is not sufficient to remove lipid-coated viruses,
additional antiviral inactivation steps are required.
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