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History
It has long been established that animals can be
actively immunized against snake venom
by repeated parental injections, with increasing doses
of venom (Sewall, H., 1887.) Active
immunity against snake venom has also been attempted
and demonstrated in humans using
toxoid derived using the venom of the Australian Tiger
snake (Notechis scutatus)
(Wiener, S., 1960.) A large-scale immunization trial
was also implemented using a toxoid
of the venom from the Habu (Trimeresurus flavoviridis)
(SAWAI et al. 1969). The most
remarkable case of active immunity in humans is of one
William E. Haast of the Miami
Serpentarium. He originally obtained immunity using
venom from the Cape Cobra,
(Naja nivea) then later included venom obtained
from the Indian Cobra, (Naja naja)
and King cobra (Ophiophagus hannah). His
case demonstrated cross-resistance between
venoms of different species. He subsequently was
bitten by species other than was used in
the inoculations and suffered little or no systemic
reactions. The most remarkable followed
after being immunized with the Cape cobra (Naja nivea).
He was bitten by the Blue krait
(Bungarus caeruleus) and survived without any
antiserum. This case unlike most other cases
of human immunization against snake venom involved using
venom that was not detoxified
(Haast, W.E, Winer, M.L. 1955). Later other venoms
were included into his inoculations.
Presently more than thirty venoms are used in his
booster shots. He has subsequently
survived more potentially lethal bites than any other
human. These bites included some of
the most lethal species. The Tiger snake (Notechis
scutatus) Russell's viper
(Daboia russelii) and Saw scale viper
(Echis carinatus) are a few of the many
notable
species he has survived bites from. He is presently
ninety four years old and in good health.
Mr. Haast pioneered human immunizations when started
immunizations in 1948.
(Haast, W.E., Nancy Miami Serpentarium 2005 personal
communications)
1
It has long been established that animals can be
actively immunized against snake venom
by repeated parental injections, with increasing doses
of venom (Sewall, H., 1887.) Active
immunity against snake venom has also been attempted
and demonstrated in humans using
toxoid derived using the venom of the Australian Tiger
snake (Notechis scutatus)
(Wiener, S., 1960.) A large-scale immunization trial
was also implemented using a toxoid
of the venom from the Habu (Trimeresurus flavoviridis)
(SAWAI et al. 1969). The most
remarkable case of active immunity in humans is of one
William E. Haast of the Miami
Serpentarium. He originally obtained immunity using
venom from the Cape Cobra,
(Naja nivea) then later included venom obtained
from the Indian Cobra, (Naja naja)
and King cobra (Ophiophagus hannah). His
case demonstrated cross-resistance between
venoms of different species. He subsequently was
bitten by species other than was used in
the inoculations and suffered little or no systemic
reactions. The most remarkable followed
after being immunized with the Cape cobra (Naja nivea).
He was bitten by the Blue krait
(Bungarus caeruleus) and survived without any
antiserum. This case unlike most other cases
of human immunization against snake venom involved using
venom that was not detoxified
(Haast, W.E, Winer, M.L. 1955). Later other venoms
were included into his inoculations.
Presently more than thirty venoms are used in his
booster shots. He has subsequently
survived more potentially lethal bites than any other
human. These bites included some of
the most lethal species. The Tiger snake (Notechis
scutatus) Russell's viper
(Daboia russelii) and Saw scale viper
(Echis carinatus) are a few of the many
notable
species he has survived bites from. He is presently
ninety four years old and in good health.
Mr. Haast pioneered human immunizations when started
immunizations in 1948.
(Haast, W.E., Nancy Miami Serpentarium 2005 personal
communications)
2
Case
This case, before us now, is another using venom that is
not detoxified. This case involved
a male subject, the author, who is of good health and
condition. The immunization was carried
out as a prophylaxis in case of envenomation, while
engaging in venom extraction. Liquid,
non-lyophilized venom was used for convenience. All
doses are in the liquid natural form.
Detoxification was not attempted in order to eliminate
any epitope or antigenic change.
No adjuvant was added. Prior to doses of .01 ml of
pure undiluted venom, dilutions were
made using bacteriostatc water with 0.9 % benzyl.
Inoculations were administered parenterally
by intradermal injections. The course of immunization
was carried out from September 2001
to March 2005. Inoculations were given one week to one
month apart. On two accounts
there where delays between inoculations of a period of
two months. Immunization commenced
using venom from Egyptian cobra (N. haja) and
Forest cobra (N. melanoleuca) at a dosage
of .001 ml. These venoms were rotated between
inoculations. Later Cape cobra (N. nivea)
venom was used as a substitute to replace other naja
venoms. This variation from the
original immunization schedule was done because of the
known toxicity of N. nivea venom.
It being the most toxic of all cobra venoms (U.S.
Department of the Navy, Bureau of Medicine
and Surgery, POISONOUS SNAKES OF THE WORLD, 1991). It
is the hypothesis of the
author, that because of its toxicity, N. nivea
would provide the best immune protection against
most other similar naja venoms. The use of N.
nivea venom commenced after the inoculation
doses of the other naja venoms were .01 ml. At this
stage of the immunization when the use
of different, but similar venom was implemented, a lower
dose of .005 was used initially.
In this case, immunity obtained using the other naja
venoms proved affective in that no
substantial reactions occurred following initial and
subsequent injections with N. nivea venom.
Due to the absence of systemic reactions and only
minor local reactions, these doses were
doubled with each inoculation until the previously used
dose as with the other venom was
obtained. This stage of immunizations continued with
these venoms until a dose of .02 ml of
undiluted liquid venom was used. During this course no
serious systemic effects were
experienced. General malaise was experienced during
earlier inoculations. On a few
occasions pyrexia was also experienced.
3
Systemic effects decreased with repeated injections of
the same amount. Local reactions
always consisted of an immediate wheal, erythema,
ecchymosis, and subsequent swelling
distal to injection site. Edema sometimes encompassing
the entire limb and usually subsided
within 2 days. Initial and higher doses always resulted
with local necrotic ulcerations, acute
cellulitis and subsequent holes when the necrotic tissue
was debrided and/or sloughed from
injection site. The necrotic ulcerations and cellulitis
would also progressively show signs of
healing within 2 days. During the course of these
inoculations, it was also noted that after
lapses of two months, the only noticed reduction in
immunity or immune responses were
noticed in these local effects. Shorter intervals
between inoculations produced less of a
local reaction. Systemic involvement remained more
consistent, with no changes in reactions
after these 2-month lapses. The course of immunization
using venom of the Eastern Green
Mamba (Dendroaspis angusticeps) was started when
the dose of naja venoms were .02 ml.
The same initial dose, as used with the others, of .001
ml was used. The effects of this of
D. angusticeps venom proved substantially different,
than the naja sp, used with the previous
inoculations. It proved different with its extremely
rapid onset of symptoms. This was possibly
due to the facilitating ability of the dendrotoxins and
/ or to its extremely light viscosity. Snakes
belonging to the Dendroaspis genus have a
particular dreaded reputation. This is partly due to
this rapid onset of systemic symptoms. Prior to the
development of mamba antivenoms, there
where difficulties experienced in their development.
The animals often died, as a result of the
venom acting so rapidly (Krush, Haast Cobras in His
Gardens 1963). Initially, in each
case of these earlier inoculations, using D.A.
venom, numbness and tingling sensations of the
lips, mouth and brow was experienced immediately
upon injection. Sore throat and muscular aches later
followed these symptoms of the
earlier inoculations. Some of these earlier doses which
resulted with notable reactions, would
persist into the next day with symptoms similar to those
following other intoxications or
flu-like symptoms, i.e. headaches, sore muscles and
joints.
4
The symptoms lessoned with subsequent inoculations of
the same amount. However symptoms
would return with increased doses. Inoculation doses,
up to this point, where; .001, .002,
.003, .004, .005, .006, .007ml. When inoculation doses
of this venom were .008 ml,
symptoms came on quickly, like with a “rush”, then would
begin to subside within 2 hours.
During these occasions it was required to lie down in
bed. In two accounts, recorded blood
pressures were noted with a decrease in systolic and
diastolic pressure. On one of the
inoculation using the dose of .008, the BP of 78/40 was
recorded initially. BP then fluctuated,
but gradually increasing and returned to within normal
parameters within one hour. Pulse
rates increased considerable after injections initially
along with the feeling of a “flush” hot
sensation.
Pulse rates as high as 105 per minute were recorded.
The pulse rate would
then drop to as low as 40 per
minute. The advent of these symptoms were within two
(2) minutes following injections. Vital signs would
return to normal parameters within
2 hours. The reversal
of these rapidly developed symptoms were as notably felt
as
with the onset. This is interpreted as a positive
immune response. The subsequent dosage
following the
above inoculation and adverse
symptoms was reduced to the last previous dosage without
these symptoms, so that the
previous dose, in this case .007 ml. was repeated.
Tonic muscular spasms associated with
flexion and extensions while walking, resulting with
extra movements while taking steps, were
also experienced. These spasms persisted after all
vital signs returned to normal limits, then
would gradually return to normal. However sensations
and reflex actions attributed to this
persisted into the next morning. These spasms were
possibly indications of the fasciculins or
dendrotoxins, that facilitate the release of
acetylcholine, without endogenous regulation and
control. Initially this venom did prove difficult to
use as an antigen for inoculations because
of this rapid onset of symptoms and effects. However,
once the dose of .01 ml of undiluted
was reached, all subsequent increases of dosage were
uneventful. No remarkable deviations
of vital signs were experienced following subsequent
injections of higher doses. It was after
a dose of .04 ml. undiluted D. angusticeps venom
that dose increases of venoms; N. nivea
and D. angusticeps in increments of .01 until
a dosage of .15 ml undiluted venom with no
systemic effects. At this dose of .15 ml, D.A.
venom caused only erythemas and edema of
limb distal to inoculation
5
site, with no significant signs of systemic changes.
No cellulitis or necrotic effects were
noted following any inoculations using venom of D.
angusticeps, only an immediate wheal
followed by erythema and subsequent swelling was
observed in the immediate injection
site. A challenge dose of .15ml N. nivea
venom caused no systemic effects, only the
previously described local necrotic effects. The
effects on the tissues in the immediate areas
did appear dose dependant, but only to a point. A dose
of .15 ml caused only slight increase
in the local reaction to that of. 05 ml. This is
consistent with the observations of Wiener
(Wiener,S.1960). The venom of the Western Green Mamba
(D. viridis) is 3 to 4
times more lethal than D.A venom. (Harvey et al,
1984 J. Toxicol) However, inoculations
of D.V with venom doses of .01, .02, .04, .08,
10, .15ml., given one week a part,
subsequent to D.A. immunization, were
uneventful. It remains unknown what effects
an initial higher dose of D.V. venom and what
degree of immune protection would have
been provided following D.A. immunization.
However, it is evident with the accelerated
immunization using D.V. venom without ill
effects are an indication of substantial protection.
This is possibly because the toxic constituents of
D.V. venom are similar to the combination
of D.A. and N. nivea venom. D. A.
venom does not contain potent post synoptic neurotoxins
as found in both D.V. and N. N. venom. (Harvey et. al,
1984 J. Toxicol) The absence of notable
systemic
symptoms following a dose of .15ml undiluted
venom from these species, as well as the
rapid rate at
which symptoms subsided, following earlier inoculations
is evident of some substantial
immunity. The
unsuspected adverse reactions, as noted following D.A.
dose .008 is an example of
difficulties that can be
experienced during immunizations of snake venoms that
have not been attenuated.
On the 21st of April 2005, a
bite was sustained from a four foot Eastern
diamondback rattlesnake, Crotalus adamanteus.
The bite was to the right middle finger
with both fangs and a scratch to the index
6
finger. The snake remained attached for a couple
seconds. Upon it's release one of the
snake's fangs remained in the wound. This bite was
followed by definite signs of
envenomation, i.e. blood oozing from both fangs puncture
holes, swelling and severe burning
sensation. No major systemic symptoms were
experienced. Swelling was limited to the
hand and wrist, which was less than double the normal
size. Only the wound area was
discolored, and with small blebs. No antivenin was
administered. Laboratory test; CBC,
Fibrinogen level and prothrombin time revealed no gross
abnormalities. Discharge from the
hospital was the same night. It appears evident that
despite the known marked differences
between crotalid and elapid venoms, there was
substantial immunity demonstrated in this case.
*This bite sustained from the Crotalus adamanteus is
inconclusive as an indication
of an immune response. Even so it should not be over
looked entirely. It should stimulate
curiosity. Booster inoculations are continued on a
monthly basis. The author is confident and
predicts that the unique properties of Dendroapsis
venom will hold some significance regarding
the further understanding of the generation,
transmission and reception of acetylcholine. There
also appears to be evidence, here, which suggest an
immunopotentiation between different
snake venoms as antigens. Further investigations could
reveal more information regarding
the immune responses between antigenic toxins and
antibodies produced heterologously by
inoculation of different venoms. This phenomenon may be
due to the affinity at which different
antibodies bind to antigens exogenous to the production
of that specific antibody or further
research may reveal new information regarding antibody
production and differentiation of
undifferentiated B cells. This needs further
investigation. It should be made known that the
foregoing paper is not intended as an account of any
study, but rather of the author's own
immunization schedule used and of the observations of
the effects experienced during its course.
The author wishes that this information be made
available to any and all researchers that may
find interest.
7
The author must emphasize that the risks involved in
such a procedure as the one described
above would normally be unwarranted. The reactions as
indicated are unpredictable and vary.
No standardized method has been determined and the
probability of extreme and serious
consequences great.
REFERENCES
Haast, W.E., Winer, M.L 1955.:
Complete and Spontaneous recovery from the bite of
a
blue krait (Bungarus caeruleus) Ameri. J. trop. Med.
Hyg. 4 1135-1137
Haast, W.E, Nancy Miami
Serpentarium 2005: Personal communications
Harvey, A.L., Anderson, A.J. Mdugka, P.M., and Karlson,
E. (1984): Toxins from
Mamba venoms that facilitates
neuromuscular transmission. J. Toxicol. Toxin
Rev.3 91-137
Harvey, A.L. editor, 1991: SNAKE
TOXINS International Encyclopedia of
Pharmacology
and Therapeutics ISBN 0-08-040294-1
Kursh, H. 1965 Harvey House, Inc.
Pub. Cobras In his Gardens, biography W.E. Haast
Menez, Andre., Immunology of Snake
Toxins (1991): Harvey, A.L editor, SNAKE TOXINS
pp 5-90 ISBN 0-08-040294-1
U.S Dept. of Navy (1991) ( Bureau
of Medicine and Surgery) POISONOUS SNAKES
OF THE WORLD,
ISBN 0-486-26629-X
SAWAI., Kawamura, Y., T., Okonogi,
T., Ebisawa, I (1969a): Studies on improvement
of
treatment of habu (Trimeresurus flavoviridis)
bites Jap. J. exp. Med. 39, 109-117
SAWAI, Y., Kawamura, Y., T., Okonogi, T. Ebisawa I
(1969b): Field trial of prophylatic
inoculation
of the habu (Trimeresurus flavoviridis) venom
toxoid. Jap. J. exp. Med. 39, 197-203
Sewall, H. (1887): Experiments on
preventive inoculation of rattlesnake venom., J. Physiol
(Lond) 8, 203-210
Wiener, S., (1960)Active
immunization of man against venom of Australian tiger
snake
(Notechis Scutatus), Amer. J. trop. Med Hyg. 9,
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LEE MOORE
Serpentoxin Laboratory
P.O Box 565
Fort McCoy, Florida 32134- 0565
USA
email
LeeMoore@Serpentoxin.com
1
Professor Alan Harvey
Department of Physiology and Pharmacology
University of Strathclyde
27 Taylor Street Glasgow G4 0NR, UK
RE: AH/2005/000156
HUMAN IMMUNIZATION TO ACQUIRE ACTIVE IMMUNITY
AGAINST SNAKE VENOM
Dear Dr. Harvey,
I apologize for the delay with responding on
this issue. I feel the subject of this
letter is important. I pray it is given proper
consideration.
I wish to make it clear that I commend Toxicon's
and The International Society
on Toxinology for its work and dedication to the ends of the
standardization
and organization of information concerning snake toxins.
These efforts have
provided a forum, unparalleled by any other. It
has enabled researchers from
across the globe a means to participate as a whole, towards the
advancements
in toxinology.
I do wish, however, to express some concerns
directly related to the journal's
written evaluations relating to the above manuscript.
It is to be expected that
any “risky” protocol such as the one presented would be
under harsh scrutiny.
However, the reviewers of this paper where not objective
and did not represent
the papers most obvious objectives. The objective was
merely to make available
information concerning this particular case of
immunization. It is not intended as
a proposed immunization schedule for others to use, but merely as an
account
of the reactions experienced. Allow me first
response to “Reviewer No. 33 title
“Mere Masochism or certifiable madness?” Some of the
greatest advances came
with risk. Medicine has always been latent with risk. One of
the first thoughts
that came to mind was that of Edward Jenner's vaccine
and how many had not the
convenience of not having to weigh the risks between
exposing themselves and
their own “young” to the vaccine (cowpox virus) to
protect from the risk of smallpox.
This was a new concept that was far from being fully
understood and with many
unknowns. I would like to add a discovery actually
made by a young uneducated
milkmaid.
My life's work has directed me in a direction
involving risks related to snake venom
extraction. The point being is that these risks can be
logically decided upon. The risk
of snake bite is very real regardless of the caution
exercised. Reviewer No. 33 also
seemed alarmed at the mention of swelling and necrosis.
It is not only “risk” but
usually at some physical consequence taken by either
animal or human. A review of
immunization schedules and processes of the immunization
of horses, one would see
similar reactions to a lesser degree, of course, due to
the Dose-Response
relationship
because of the mass/dose ratio. The horse obviously has
much more of an advantage.
To address reviewer No. 33 statement “There is no
demonstration of the induction
of specific or paraspecific immunity, merely his
apparent tolerance of increasing doses
of venoms.” This statement is a contradiction
in terms. “......... tolerance of increasing
doses of venoms.”? Tolerance of increasing doses is definitive of immunity.
I will
address this further later in this letter.
2
I agree entirely that the bite
sustained from the Crotalus adamanteus is
inconclusive
as an indication of immunity. Even so it should not be
over looked entirely. It should
stimulate curiosity. It was apparent that it
was not entirely a “dry bite”, due to the
subsequent surgical debridment of some subcutaneous
necrotic tissue.
I will have to disagree
entirely concerning Reviewer No. 33 concerning the
spurious
opinion that Bill Haast has not demonstrated a high
degree of immunity. His case
demonstrated cross immunity as was indicated with the
well documented case of the
bite of the blue krait in the New England Journal of
Medicine. This citation can be
found in the letter to the editor. His blood’s
serum has been used as an antiserum
and has saved lives. This is well documented.
The fact that serious envenomation will always
be a risk regardless of immunization
was never disputed in the submitted manuscript nor is it here.
Immunity of snake
toxins is relevant to the amount of toxin vs. antibody
titer. It is always possible to
overwhelm the antibodies and a very real risk! There is
no “silver bullet” as
prophylaxis for envenomation. However a remarkable
IgG, antibody titer is of
obvious advantage. Along with this consideration
the term resistance may be more
suitably used in its stead.
Reviewer No. 33 also stressed that the author
has “proved nothing”. It was not the
paper's intention to prove anything. There was no
attempt to present this data as a
study or experiment. It was just intended to relay what
had been done to immunize
a human, myself.
“......... merely his apparent tolerance of
increasing doses of venoms.”
Maybe, but an injection of .15 ml of N. nivea
or D. angusticeps
venom, presently
without any effects is an indication that there would be
an advantage in the case
envenomation and a subsequent higher dose. The
undisputable fact remains that
this dose would ordinarily be critical.
Reviewer No. 13 was concerned and stated that
“Dosages such as .001ml is not
reliable data to describe or estimate venom activity”. An
argument that measured
doses in liquid form are not exact could well be made”.
However to state “…is not
reliable data to describe or estimate venom activity”,
is unreasonable. It is merely,
as stated by this reviewer, an estimate and does present
consistency. Lyophilized
venom of these liquid doses would reveal consistency in
dry milligram doses, would it
not?
I admit there where some potentially serious
consequences. These are noted and
described in the manuscript. These facts where not
omitted. They could have easily
been omitted and just presented the procedure as without
any difficulty, but that
would not have been objective or ethical. In
response to the reviewer No. 33 concern
of not addressing the “very important theoretical
objections ....” the facts that would
clearly raise these important objections are clearly
presented. Despite the comment
by reviewer No. 33 that this paper, “would be of
interest only in the psychiatric
literature”. The author did not present
the manuscript to such and therefore felt it
not appropriate to convince anyone on ethical issues.
The risks are very real when one injects foreign
substances, especially those that
are termed and classified as dangerous venoms into the
body. However, the risks
of these venoms are also very real when one engages in
venom extraction. I argue
that these risks can logically be “weighed” and decided
upon, but only by the
individual involved. Perhaps the paper the
reviewers would prefer would be titled
Snake bite Vs. Immunization? The theory behind this
immunization is fundamental
and has been accomplished numerously with animals. The
risks and ethical issues,
as stated earlier, must be evaluated by the individual.
I do strongly advise against
this procedure, except for cases involving an extreme
risk of envenomation. In
which cases, the risks and potential benefits should be
fully investigated and decided
upon by the individual. I have continually been
adamant that I would never encourage
nor assist any individual with their own immunization.
The risks of miscalculations,
adverse effects directly related to the different toxins
and anaphylactoid reactions
are all very possible and real risks. There are
numerous risky variables. This,
however, was not the subject of the presented
manuscript.
3
I have found no other more comprehensive work on
the subject of toxinology than
Snake Toxins
edited by yourself and that of Venomous and Poisonous
Animals by
Dietrich Mebs. The accomplishments of the International
Society On Toxinology are
unparalleled. I do understand the Journals
concerns, whereas it is the journal's
responsibility to express such concerns, it should
equally be responsible to relay
documented information. If the information is
challenged, investigate it further.
To my knowledge, there have not been many
immunoassays done in humans. The
long term effects of snake venoms on humans have not yet
been investigated. This
information would be of obvious benefit to the investigation of using
snake toxins in
human medicine.
The International Society on Toxinology and Toxinology
as a relatively new field,
with established roots in toxicology and microbiology,
has the edge of innovation.
Science has always been jealous of innovation and
instead turns towards “focus”.
This is good, in it self, but as a result is often
blinded to other aspects. It operates
under predisposed knowledge, which are often assumptions
based on present
knowledge or on the lack of knowledge. For
instance science tells us that only 3%
of DNA is operational. The remaining 97%, because the
use is not known, is
actually termed “Junk DNA”. Science is missing
something! Possibly 97% of
something! Point being we as scientist must be
willing to think outside the “box”.
The principles of immunization presented in the
manuscript are not theory, but fact.
It involved fundamental principles. The dilemmas, of
course, are the risks and
unknowns that are involved. Whereas, as stated by
the reviewer, it may be unethical
to use others as “guinea pigs” who can determine if it
is unethical for an individual
to decide between the risks and possible benefits of
this kind of prophylactic
immunization? The individual, being the only
benefited or harmed, is the only one
that can be qualified, to make such decisions.
The purpose of the above mentioned manuscript,
as stated was not to prove anything,
but to present information. This is why it was presented
in the form of a “letter to the
editor”, not “short communications” etc. This
information should be of interest to
those with intentions of expounding further on this
subject. I challenge the Journal
and the Society to reconsider its position on
investigating further these issues, to
address and publish on this subject and to make
available for inspection what has
already been accomplished. Bill Haast, Myself and
a few others have immunized
themselves. Ethical issue can be made and perhaps
should be, but do not withhold
information that has been presented based solely on
subjective concerns. This
information will not be suppressed. Publish this
manuscript to further research!
Sincerely,
Lee Moore
Serpentoxin Laboratory
P.O. Box 565 Fort McCoy, FL. 32134-0565 USA
email:
LeeMoore@Serpentoxin.com
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