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http://www.house.gov/reform/hearings/healthcare/99.08.03/kinsbourne.htm
Presentation
to the Committee on Government Reform
Topic: Vaccines: Finding a Balance between Public Safety and Personal Choice
Marcel
Kinsbourne, M.D.
August 3, 1999
The remarks that follow are
based upon my training and experience as a pediatric neurologist and my
familiarity with the scientific method, as well as my participation as a
medical expert in proceedings that evaluate alleged vaccine injury under the
terms of the National Vaccine Injury Compensation Act.
Types of Vaccine Injury
Offsetting their undoubted
public health benefits, vaccinations incur the risk of a range of adverse side
effects, some of which rarely cause long lasting or even permanent impairment
of health. Depending upon the nature of the vaccine, major side effects fall
into three categories, as follows:
Toxic: Killed bacteria may
release toxins as their cell bodies break up. An example is pertussis vaccine,
which contains at least one substance that can be poisonous to brain cells.
When the toxin injures the brain, this occurs anywhere from a few hours to a
few days after the vaccination.
Infectious: A vaccine that
consists of attenuated virus particles may cause the very infection that it was
intended to prevent. An example is oral polio vaccine. The infection presents
after an incubation period of a number of days during which the virus
multiplies. The virus may even remain latent in cells of the body for much
longer periods of time, and then cause disease.
Autoimmune: The body responds
to the vaccine with an immune reaction that attacks its components. Sometimes
the immune reaction also attacks a constituent of the body itself, which bears
some chemical resemblance to a constituent of the vaccine. Reports of cases in
which nerve cells have been attacked have been published for tetanus, influenza
and measles vaccines. The self-attack is the result of a cascade of
biochemical changes which takes at least five days to cause clinically
observable disease, and may take at least up to six weeks.
In view of these hazards,
safety precautions are called for. This task is not straightforward, for
reasons such as the following:
Factors that Complicate
Safety Precautions
1. Any
disease that can be caused by a vaccine can also be caused by other agents. To
help distinguish causation from chance association, epidemiological studies are
often required. These studies are typically time-consuming and
resource-intensive. Many potential adverse effects of vaccines have not been
systematically studied with the methods of epidemiology. The inventory of side
effects of vaccines remains incomplete.
2. Common
adverse side effects are likely to be detected during pre-marketing clinical
trials. Rare side effects would most likely be overlooked, given the modest number
of participants that is customary in clinical trials.
3. Not
all adverse effects occur within days or a few weeks of vaccination. Autoimmune
disorders may take a month or two to emerge. Virus particles may even remain
latent for lengthy periods of months or years, before they begin to trigger
diagnosable disease. An example of a combination of vaccines that can cause an
autoimmune disorder is MMR (measles-mumps-rubella). Another example may be
Hepatitis B vaccine.
4. Even
when an injury occurs soon after a vaccination, this may not immediately be
noticeable. This applies generally to injuries of the developing nervous
system, regardless of the cause. Such neurological syndromes as cerebral palsy
and developmental language disorder may come to light months or years after the
brain damage was inflicted. The effects of severe injury may take years to show
up, for example as learning and attention problems.
5. When
several vaccines are given at the same time, they may have adverse effects that
none of the individual vaccines have when they are given by themselves. Giving
many vaccines at the same time is becoming increasingly prevalent, especially
to captive audiences like infants. A possible example is measles and mumps
vaccines as administered simultaneously in MMR. There is reason to suspect that
this combination may cause inflammatory bowel disease and developmental
regression into an autistic state in some children in the second year of life.
Post-Marketing Monitoring
The implications of points 1
through 5 are that, at the very least, after vaccines come on the market, they
should be monitored comprehensively and for long periods of time. In many
instances, particularly for vaccines that have been newly introduced,
large-scale prospective epidemiological studies are required. The ongoing
passive post-marketing surveillance (VAERS) has shortcomings. Pertussis vaccine
illustrates this point.
Whether an adverse event that
immediately follows DPT vaccination is reported depends on pediatricians quite
variable levels of awareness of, and index of suspicion for, such events. The
ability of agency personnel to evaluate the adverse effects that are drawn to
their attention can also be unreliable. It is well known that some lots of
pertussis vaccine are associated with a disproportionately high number of
notifications of adverse events. These are termed hot lots. However, the
manufacturer is protected by law from disclosing the number of doses that
derive from a given lot. Therefore, one lacks the denominator of the function
which would reveal whether a given lot appears hot because it is more toxic,
or because it is the source of more doses. Be that as it may, hot lots offer
the possibility of danger to children. Nonetheless, I have never heard that a
hot lot has been ordered withdrawn on the basis of VAERS surveillance.
Since different lots of DPT
vaccine vary greatly in the concentration of bacteria per unit volume, and
therefore in the amount of potential toxin they contain, even when they are
produced by the same manufacturer, research to determine whether hot lots
contain relatively high levels of bacteria and toxins would seem important. A
chemical/bacteriological study that compares hot lots with standard lots seems
indicated.
We anticipate that the newly
licensed acellular pertussis vaccine will cause far fewer serious adverse
neurological reactions, but we do not yet know this for certain. In any case,
many children still receive the whole cell pertussis vaccine, with its cargo of
potentially harmful endotoxin.
Studies of vaccine safety could
be supported by initiatives of the National Institutes of Health, with
specially earmarked funds. Requests for applications for research funding could
be issued, and the applications be subjected to the customary NIH peer review
process.
Informed Consent
The remote but real risk of
serious disease that attends vaccinations must be scrupulously and
comprehensively disclosed to the parents of the children that await
vaccination. In a busy pediatric practice this is not an easy matter, and not
all parents readily understand what some of the risks actually entail. It would
be helpful if the CDC were to develop handouts that are both comprehensive and
user-friendly, that list possible adverse side effects for each vaccine. These
handouts should include information about what health and behavior changes
parents should be alert for after the vaccination. I suggest that parents be
given copies of such handouts for each vaccine well ahead of the projected date
of vaccination, so that they have sufficient time to digest the information,
and to ask any questions they might have. This might perhaps even be done
before their newborn is discharged from the hospital.
Personal Choice
Immunization programs most
effectively serve the public health if most members of the target population
participate. Nonetheless, personal choice is a civil liberty that must be
respected.
The estimates of risk offered
by medical authorities often diverge greatly from those assumed by some members
of the community. It may never be possible to reconcile these entirely.
However, I believe that almost all parents would favor having their children
vaccinated if more research on risk factors had visibly been performed. This
includes not only identifying adverse events that might happen, but also
detecting any predisposition that children in particular families might have
that increase such risks.
A genuine and vigorous effort
to identify risk factors would help dissipate the impression that some citizens
have formed that vaccine safety is not a high priority. The Institute of
Medicine (1997) publication, Vaccine Safety Forum, presents some promising
suggestions for risk factor research, particularly for those effects that arise
from autoimmune reactions.
Compensation for Vaccine
Injury
Congress has mandated a
compensation program to meet the needs of children who were injured by a set of
required vaccines. Congress made it clear that this program was to be both
generous and expeditious, but in my experience as a medical expert in many such
proceedings, I have found that this has not usually been the case. Although the
Special Masters who adjudicate the Petitions for Compensation are generally
both highly competent and compassionate, the proceedings in numerous cases extend
over many years. This foils the intent of Congress that the proceedings be
non-adversarial and leaves even those families whose claims are ultimately
judged to have merit, unassisted and often in severe financial straits. The
financial burden of raising a handicapped child can be severe. It also burdens
the law firms that assist Petitioners with expenses that are not met for up to
a decade. This has a chilling effect on the participation of attorneys in the
Vaccine Injury Compensation Program, and thereby limits the choice of citizens
who wish to file petitions. Also, a series of Rule changes as of 1995 has so
severely constricted the definition of Table Injury (an injury presumed by the
statute to have been caused by the vaccine) in the case of pertussis vaccine
(the vaccine that is complained of in the great majority of petitions), that
those who nowadays file for compensation must anticipate a lengthy, complex and
arduous proceedings with uncertain outcome.
Statute of Limitations
Compensation for injuries due
to Hepatitis B vaccine has recently been authorized, retrospective to 1990. The
Statute of Limitations for claims in regard to injuries that occurred more than
three years ago takes effect this Friday, August 6th. Efforts to
publicize this fact appear to have been less than enthusiastic. Unnotified
citizens who feel that they or their children were injured by this vaccine
between 1990 and 1996 will soon be without remedy. An outcome so clearly
counter to the spirit of the National Vaccine Injury Compensation Act might be
of interest to the Committee on Government Reform.
ALL
INFORMATION, DATA, AND MATERIAL CONTAINED, PRESENTED, OR PROVIDED HERE IS FOR
GENERAL INFORMATION PURPOSES ONLY AND IS NOT TO BE CONSTRUED AS REFLECTING THE
KNOWLEDGE OR OPINIONS OF THE PUBLISHER, AND IS NOT TO BE CONSTRUED OR INTENDED
AS PROVIDING MEDICAL OR LEGAL ADVICE. THE DECISION WHETHER OR NOT TO
VACCINATE IS AN IMPORTANT AND COMPLEX ISSUE AND SHOULD BE MADE BY YOU, AND YOU
ALONE, IN CONSULTATION WITH YOUR HEALTH CARE PROVIDER.