|Asunto:||[LEA] Environmental Risks of Genetically Engineered Vaccines|
|Fecha:||Miercoles, 15 de Noviembre, 2000 11:44:36 (-0300)|
|Autor:||Amigos en Defensa de la Gran Sabana.AMIGRANSA/ Orinoco Oilwatch <amigrans @............ve>
THIRD WORLD NETWORK INFORMATION SERVICE ON BIOSAFETY
15 November 2000
Dear friends and colleagues,
This mail-out is an abstract from the summary of 'An Orphan in Science:
Environmental Risks of Genetically Engineered Vaccines', a research report
written for and published by the Directorate for Nature Management of the
Norwegian Ministry of Environment. <www.naturforvaltning.no>
The report was written by Prof. Terje Traavik, Professor and Head of
Department of Virology, University of Troms÷ and Director, Norwegian
Institute of Gene Ecology, Troms÷, Norway.
According to Prof. Traavik, "...from an ecological and environmental point
of view many first generation live, genetically engineered vaccines are
inherently unpredictable, possibly dangerous, and should not be taken into
wide-spread use until a number of putative problems have been clarified",
and that "the risks and hazards discussed are most certainly within the
realm of possibility, and according to the precautionary principle they
should be subject to preventive measures".
This report underscores the need to also regulate genetically engineered
pharmaceuticals and medical applications. At the national level, domestic
laws and regulations should also cover the use of genetic engineering in
With best wishes,
Third World Network
228 Macalister Road
An Orphan in Science: Environmental Risks of Genetically Engineered Vaccines
Prof. Terje Traavik
University of Troms÷ and Norwegian Institute of Gene Ecology, Troms÷, Norway
Some types of genetically engineered or modified vaccines that are now
being developed pose potential ecological and environmental risks. Such
vaccines may soon be in widespread use. The risks and hazards are most
certainly within the realm of possibility, and according to the
Precautionary Principle they should be subject to preventive measures. In
practice, however, the risks are considered to be non-existent, since they
have not been supported by experimental or epidemiological investigations.
This, again, is a "Catch-22" situation, in the sense that such
investigations have not been performed at all.
At the present, the definition of "safety" is very narrow in vaccinology.
"Safety research" is occupied with prospects of unintended and unwanted
side effects with regard to the targeted vaccinees themselves, or
non-targeted individuals within the same species. This narrowing of
conception and research strategies may leave potential hazards unapprised
until they actually happen.
The main purpose of this paper is to raise awareness and catalyze
discussions. If this in its turn may contribute to having resources
available for public funding of independent research, the efforts of the
author have been well rewarded.
Immunity and vaccination
Vaccination is a form of prevention or prophylaxis of infectious disease
and cancers. The reasons for giving priority to prevention and prophylaxis
are stronger than ever, as development of resistance in microorganisms,
viruses and cancer cells are reducing the therapeutic opportunities offered
by chemotherapeutics and antibiotics.
Through their continual battle with microorganisms and viruses, vertebrates
have evolved an elaborate set of protective measures collectively termed
the immune system. Infection with a specific disease agent may initiate
immunity to that agent, and an individual that is immune to a specific
infectious agent will be left unharmed when infected by that agent again.
Vaccination intends to provide individuals with immunological protection
before an infection actually takes place. However, the immune system is
very complex, and immunity against different infectious agents is based on
fine-tuned balances between the various types of cells, signal substances
and antibodies that make up the total immune system. For some disease
agents cellular immune reactions are more important, for others specific
antibodies are essential for protection. Because vaccination against a
threatening disease may take place many years before exposure to the
disease-causing agent, immunological memory is a critical factor. A
long-lived immune response that may be mobilized and augmented rapidly when
called for is essential. Furthermore, local immunity on the epithelial
surfaces that are the portals of entrance to the body for most infectious
agents is very important.
Until recently, most traditional vaccines were of the "whole disease
agent"-type: after varying degrees of purification, the whole bacterial
cell or virus particle was used for immunization. Such vaccines might be
killed, inactivated or "live".
By modern techniques, "killed" vaccines may be based on single proteins
purified extensively to constitute safe preparations with seemingly no side
effects. However, in general such vaccines have given short-lived general
immune responses, and weak local immune responses. This may, however, be
due to rather crude and inadequate delivery systems for such vaccines.
Live vaccine agents infect the vaccinees, but have had their disease
provoking abilities attenuated. "Live" vaccines often give stronger
mobilization of all effector parts of the immune system, and in many
instances also good local immunity. The most prominent drawback of such
vaccines is that they may revert to their full disease-causing potential.
Genetically engineered vaccines and their potential risks
Synthetic and recombinant vaccines are produced under contained conditions.
Only a polypeptide which may confer protective immunity to a given disease
agent are brought out of the production unit and used as vaccine. Such
vaccines carry the same advantages and disadvantages as traditional
"killed" or "subunit" vaccines. It is conceivable that new vaccine delivery
systems and basic knowledge about immune system interactions will make
these vaccines more efficient in the near future. It is difficult to
imagine such vaccines posing ecological and environmental risks.
Genetically modified viruses and genetically engineered virus-vector
vaccines carry significant unpredictability and a number of inherent
harmful potentials and hazards. The immunological advantages of such
vaccines are related to the fact that the viruses are "live" and infect the
vaccinated individuals. It has, however, been demonstrated that minor
genetic changes in, or differences between, viruses can result in dramatic
changes in host spectrum and disease-causing potentials. For all these
vaccines, important questions concerning effects on other species than the
targeted one are left unanswered so far. The opportunity of a genetically
engineered vaccine virus to engage in genetic recombinations with naturally
occurring relatives is another unpredictable option. The new, hybrid virus
progenies resulting from such events may have totally unpredictable
characteristics with regard to host preferences and disease-causing
potentials. Furthermore, when genetically modified or engineered virus
particles are broken down in the environment, their nucleic acids will be
released, representing the same unpredictable risk potentials as the DNA
and RNA vaccines discussed below.
Much basic work is needed before recombinant bacterial vectors may be taken
into practical use. For instance, it was recently demonstrated that
genetically engineered bacteria might transfer their new gene efficiently
to indigenous bacteria in the mammalian gut. This potential risk has not
been investigated for bacteria that are now being genetically engineered as
Naked DNA vaccines are engineered from general genetic shuttle vectors.
They are constructed to break species barriers. Naked DNA may persist much
longer in the environment than dogmas held just a short time ago.
Consequently, upon release or escape to the wrong place at the wrong time,
horizontal gene transfer with unpredictable long- and short-term biological
and ecological effects is a real hazard with such vaccines. There is also
growing concern about harmful effects due to random insertions of vaccine
constructs into cellular genomes in target or non-target species.
RNA vaccines may have a far way to go before any of them find practical
use. Although easy degradation is a serious problem with RNA work in the
lab, RNA may be surprisingly resistant under natural conditions. At the
present time recombination between related RNA molecules has become a real
concern. RNA recombination is far more common than dogmatic views held
Genetically engineered plants produce "edible vaccines". Little is known
about the consequences of releasing such plants into the environment, but
there are examples of transgenic plants that seriously alter their
biological environment. A number of unpredicted and unwanted incidents have
already taken place with genetically engineered plants.
Some environmental pollutants (xenobiotics, i.e. PCBs, dioxins, heavy
metals) may interact with genetically engineered vaccines, adding to their
unpredictability and the inability to perform meaningful risk assessments
Changes in attitudes among scientists, medical doctors as well as
politicians are badly needed. Recent experiences ought to call for humility
with regard to environmental effects of science and technology. In many
cases, "experts" were proven wrong after damage had been done. To the
extent that any prior investigations of damaging effects had been
undertaken, methods used were inadequate and only capable to reveal
short-term effects, whereas the long-term impacts were the most important
There is a most striking lack of holistic and ecological thinking with
regard to vaccine risks. This seems to be symptomatic for the real lack of
touch between research in medicine and molecular biology on one hand, and
potential ecological and environment effects of these activities on the
In order to make reliable risk assessments, perform sensible risk
management with regard to genetic engineering in general, and genetically
engineered vaccines in particular, much pertinent knowledge is lacking. The
prerequisite for obtaining such knowledge is science and scientists
dedicated to relevant projects and research areas. It must be the
responsibility of the national governments and international authorities to
make funding available for such research. On one hand, this is obviously
not the responsibility of producers and manufacturers. On the other hand,
risk-associated research must be publicly funded in order to keep it
totally independent, which is an absolute necessity for such activities.
Vaccinology is the "Holy Grail" of medicine. Nevertheless, there are other
ways of preventing infectious diseases in humans and animals, and these
should not be ignored. Many of the most burdening infectious agents of
mankind and its domesticated animals are caused by pathogens that have
reservoirs and are circulating among wildlife animals. By increasing our
knowledge about these reservoirs, their occurrence, the transmission routes
within and out of the indigenous ecosystems, we might be able to break
transmission chains, or keep our activities out of dangerous ecosystems.
There is a void in knowledge about the ecological interactions of many
important pathogens. This field is to some extent subdued by the confidence
in vaccines, and hence it is a scientific orphan.
A number of relevant references are given in:
Traavik, T. An Orphan in Science: Environmental risks of Genetically
Engineered Vaccines. Research Report for DN 1999-6. Directorate of Nature
Management, Trondheim, Norway, 1999.
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