Mandating
the Smallpox Vaccine: Benefits and Risks in the 21st Century
Prepared
by
Matthew
Haglund
May
2, 2005
Table
of Contents
Executive
Summary …………………………………………………………………… i
Abstract …………………………………………………………………………… 1
Introduction …………………………………………………………………………… 2
Results
History
of Smallpox Vaccination and Their Respective Programs …………………… 3
Background
Information on Smallpox Virus and Symptoms ……………………………
5
Information
on the Smallpox Vaccine ……………………………………………
6
Complications
of Vaccination …………………………………………………………… 8
Conclusions
Smallpox
Vaccination Should be Voluntary in the 21st Century ……………………11
Glossary ……………………………………………………………………………13
Bibliography ……………………………………………………………………………14
Illustrations
Victim
of Smallpox ……………………………………………………………………
3
Progressive
Vaccinia ……………………………………………………………………10
Mandating
the Smallpox Vaccine: Benefits and Risks in the 21st Century
Executive
Summary
Smallpox
has been eradicated from the natural world since 1977 (Kiang, 2003). However, the recent terrorist attacks on
Smallpox was known to kill almost 30% of
those it affected, and scared or blinded those who survived (“Position
Statement on Smallpox Vaccination Programs”, 2003). Caused by the virus variola, it is one of the
most deadly diseases ever known to mankind.
Some experts estimate that more people have been killed throughout human
history by smallpox than by any other cause (Napolitano, 2004). The virus is expelled from a victim via
respiratory droplets and later inhaled, causing infection (Cassimatis,
2003). Affecting the face and arms first
and later the torso, smallpox infection results in large, virus shedding
pustules covering the entire body. After
a month long fight with the disease, the victim either dies or recovers. Survivors will be left with horrible scars,
caused by the receding pustules (Tennyson, 2004). Because of the severity of and misery caused
by the disease, the World Health Organization organized efforts to eradicate
smallpox from the natural world through vaccination. They were successful, and in 1977, the last
know case of smallpox occurred in
The smallpox vaccine was invented in 1796
by English doctor Edward Jenner (Lorrich, 2004). While Jenner’s vaccine used the mild cowpox
virus to immunize the masses, modern smallpox vaccines uses the somewhat
similar vaccinia virus instead (Fang, 2005).
Unlike many common vaccines today, the smallpox vaccine actually uses a
live virus (vaccinia), not a chemically or mechanically killed one (Tennyson,
2004). This means that vaccination
causes an infection by vaccinia, resulting in immunity to infection from smallpox. Due to this fact, many serious side effects
associated with smallpox vaccination.
Besides typical swelling at the
vaccination site and fever, life threatening side effects may occur after
receiving the vaccine. Past studies have
shown that around 1 person per 20,000 has a serious side effect due to
vaccination (“Smallpox Fact Sheet”, 2005).
These may include spreading of the virus (progressive vaccinia), heart
problems (myopericarditis) or brain swelling (encephalitis) (Plaut, 2003). Of those suffering serious side effects, it
is likely that 1 per 500,000 would die as a result (“Reactions after Smallpox
Vaccination”, 2005).
Smallpox in the hands of terrorists
certainly does pose a threat to the American public, but a smallpox
revaccination campaign has the potential to be even more deadly. Of the almost 300,000,000 people living in
the
Mandating
the Smallpox Vaccine: Benefits and Risks in the 21st Century
Abstract
Public Health Assessment Corporation, in
response to MN Research Corporation research proposal F99-W2000, has lead a
thorough investigation concerning the safety and possible reinstitution of the
smallpox vaccine for public use. Over
the past few months, lead research Matthew Haglund has studied extensively both
the smallpox virus and the history of its vaccine. In doing so, he has created a definitive
source on the topic, designed to reeducate the scientific community and the
public on this somewhat forgotten disease.
Smallpox
is a deadly and highly contagious disease from the orthopox genus of
viruses. Although it is no longer a
natural threat, the recent terrorist attacks on
Introduction
The smallpox virus was one of the
deadliest diseases to ever plague humankind.
Due to its high mortality rate, the World Health Organization began an
intense campaign to eradicate it from nature starting in the 1960s. With the last known case occurring in Somalia
in 1979, smallpox disappeared from the consciousness of the public and medical
communities alike. Routine childhood vaccination
was halted in the 1970s due to the vaccine’s side effects, thus creating a
world in which most people have no protection from the now unnatural
disease.
The 2001 terrorist attacks on America have
recently caused a reevaluation of the necessity of smallpox vaccination. Amid fears that smallpox lab samples from
cold war Russia were sold on the black market, the administration of U.S
President George W. Bush has considered possible reinstatement of the smallpox
vaccination program in the United States.
Since 2001, enough smallpox vaccine has been purchased or produced for
every American citizen.
With
knowledge of the vaccine and its side effects at an all time low, reeducation
of the American public and medical community has become a must. Firstly, this research project hopes to aid
in future decision making concerning the vaccine, by pulling all current
information regarding smallpox and vaccination together. Secondly, it hopes to reinvigorate scientific
research on the subject, due to the relatively outdated nature of the facts and
figures presented below. The history of
the vaccine, information on the virus and the vaccine, and side effects of
vaccination will be presented below.
Recommendations concerning widespread vaccination will be discussed in
the conclusion.
Results
History
of Smallpox Vaccination and Their Respective Programs
Until
its eradication from the natural world in 1979, smallpox was one of the
deadliest diseases known to humankind.
Estimates of mortality rate vary in the literature from 30 percent to up
to 50 percent of those infected (Fang, 2005).
The first practical attempt at smallpox vaccination and control was
headed by British scientist Edward Jenner in the late 18th century. After noting the apparent inability of
smallpox to infect a person infected with the similar (though much milder)
swinepox, Jenner began to experiment with practical vaccines. He determined that inoculation with
non-lethal cowpox was both a reasonably safe and effective means by which to
immunize a population (Cassimatis, 2003).
After a successful test of the vaccine in 1796, mass vaccination began
in England later that year. By 1801 over
100,000 Britons were vaccinated using his method (Lorrich, 2004).
Despite availability of a vaccine,
widespread world use was not seen until a new and more effective version using
a modified strain of the vaccinia virus (instead of cowpox) was developed in
the early twentieth century. By the
1950s, much of the modernized world had rid itself of the virus. The last known case in the United States was
recorded in 1949 (Yantruali, 2005). At
the World Health Assembly in 1959, plans were drawn up for worldwide
eradication of smallpox through the largest and most complex vaccination
campaign ever attempted (Lorrich, 2004).
The Smallpox Eradication Unit was soon formed, enforcing mandatory
worldwide smallpox vaccination eight years later in 1967 (Fillmore, 2004). Due to the radical success of the program,
routine childhood smallpox vaccination was halted in the United States in
1972. The last known case of natural
smallpox occurred in Somalia in 1977 (Cassimatis, 2003). After only ten years, a virus that had killed
more human beings than all other diseased combined, was erased from the
globe. In 1980, the World Health
Organization announced that smallpox was officially eradicated (“Position
Statement on Smallpox Vaccination Programs”, 2003). Vaccination of United States military
personnel ended in 1990.
During the 1990s, only a few hundred
scientists and medical personnel working with smallpox in a laboratory setting
were vaccinated (“Smallpox Fact Sheet”, 2005).
Smallpox immunization can carry with it significant complications and
side effects, so only those still vulnerable were vaccinated. Since the terrorist attacks in September 2001
and the Anthrax scare in October 2001, this position has changed. On December 13th, 2002, the administration of
President George W. Bush announced the reinstatement of the U.S. Smallpox
Vaccination Program (Yanturali, 2005).
Officials feared that smallpox virus was possibly stolen from Soviet
labs and sold to terrorists during the cold war and could be used in a
biological attack (Kiang, 2003). At the
current time, only first responders, medical personnel and members of the
Department of Defense are being vaccinated (Tennyson, 2004). Since the end of 2002, over 615,000 U.S.
citizens have been revaccinated under the plan, making it the largest smallpox
vaccination effort since 1977 (Eckart, 2004).
Although officials are still discussing possible options, the government
has not recommended the vaccine to the general public. It should be noted however, that since 2001, enough
vaccine has been produced or purchased for every person in the United States
(“Smallpox Fact Sheet”, 2005).
Background
Information on Smallpox Virus and Symptoms
Smallpox is an extremely contagious DNA
virus belonging to the orthopox genus (Fang, 2005). Referred to in the scientific community as
variola, this virus has almost certainly caused more devastation to humankind
than any other single disease or disaster in history (Yanturali, 2005). Some estimate that more humans have died of
smallpox than all other diseases combined (Nepolitano, 2004). With its mortality rate of almost fifty
percent, smallpox ravaged the globe for more than 2 millennia, killing and
maiming billions of people (Cassimatis, 2003).
Those that survived were left horribly scarred and disfigured from the
force of the smallpox pustules. It was
not uncommon to lose sight or hearing after a bout with the disease.
The agent of smallpox, the variola virus,
is typically spread by respiratory droplets formed during prolonged coughing
(Cassimatis, 2003). The virus can also
be contracted from clothing and bed linens infected by weeping pustules. After entering the respiratory system, the
virus soon makes its way to the lymph nodes.
Once there, variola incubates for 7 to 17 days, after which it invades
the capillaries of the skin, causing a rash to break out on the face, arms, and
legs. Over the next week, this rash
forms lesions that eventually form the classic smallpox pustules and spreads to
body trunk. If the victim survives the
disease, the pustules will eventually scab over and fall off, leaving large scars. Typically, smallpox infection lasts around
one month (Tennyson, 2004). Until the
pustules have gone, they continually shed the virus, making the host extremely
contagious for up to thirty days (Kiang, 2003).
Ridding
the body of smallpox can be a difficult task.
Modern vaccination can be effective even after infection, but treatment
becomes difficult in later stages (“Protecting Americans”, 2002). Death can occur if the throat becomes swollen
from the disease and airway is blocked.
More commonly, smallpox has been known to kill its victims due to kidney
failure, toxic shock and pneumonia (Cassimatis, 2003). Survivors face long term complications such
as facial scars, nasal damage, ankyloblupharon, ectropion, and the
aforementioned vision and hearing loss (Tennyson, 2004).
Before smallpox was eradicated in 1977,
five strains of the variola virus existed in nature. Variola major was the most common; with
mortality rate around thirty percent.
Variola minor was a milder, often non lethal strain used for years as a
crude vaccination for variola major.
Three rare strains also existed: two with a mortality of almost one
hundred percent and one with a mortality rate of almost zero (Cassimatis,
2003). Eradication of the disease was
possible in part due to the fact that humans are the only known host for
variola. With no fear of animal vectors
harboring the virus, smallpox was eventually contained and destroyed (Lorich,
2004).
Information
on the Smallpox Vaccine
Prior
to the discovery of mutual immunogenicy between the pox viruses by Edward
Jenner in the 18th century, smallpox immunization was a brutal and dangerous
process. Through a process known as
variolation, the milder, though still deadly, form of smallpox (variola minor)
was injected under the skin of healthy patients. After a relatively mild bout with the
disease, the body was protected from the more lethal form (variola major). The technique was somewhat successful,
however many of those variolated developed full blow smallpox as a side effect
(Cassimatis, 2003). It wasn’t until Jenner created a vaccine using the cowpox
virus that vaccination became both safe and effective.
Smallpox
vaccination has improved markedly since Jenner’s vaccine of 1796. The cowpox virus of the old vaccine was replaced
almost a century ago by a more effective and efficient virus named
vaccinia. Like cowpox, vaccinia shares a
common subfamily (chorodopoxvirinae) and genus (orthopoxus) with the smallpox
virus variola (Cassimatis, 2003). This
fact that the two viruses share a common ancestor in their evolutionary lines
makes them mutually immunogenic to the human body (Fang, 2005). Once the body comes in contact with one form
(i.e. vaccinia), it will remember it, and thus make itself immune to all forms
(e.g. variola). Unlike many other common
vaccines, smallpox vaccination must always use a live virus to confer
immunity. Although somewhat modified,
today’s vaccines introduce live, active vaccinia into the body. The virus must then be allowed to replicate
for vaccination to be successful (Tennyson, 2004). The vaccinia smallpox vaccine currently in
use by the United States is Dryvax® (Lorich, 2004). Because Dryvax® uses live animals in its
production and has been deemed inhumane, a 21st century alternative known as
ACAM2000 is in production as its successor (Artenstein, 2005).
The means by which the smallpox vaccine is
administered are somewhat unique.
Instead of using a hypodermic needle and injected under the skin, a
technique called “multiple-puncture” is utilized. In multiple-puncture, a bifurcated (two
pronged) needle is dipped into the vaccine and jabbed into the upper arm or
thigh three times (Kiang). If blood does
not appear on the skin shortly thereafter, the punctures were not deep enough,
and the process is repeated. In the
three to four days following a successful vaccination, a red lump appears at
the site of vaccination (“Smallpox Fact Sheet”, 2005). This is caused be vaccinia virus replicating
and the body’s immune system responding to its presence. At this point, the recipient is considered
fully vaccinated and immune to smallpox (Kiang, 2003).
Seven to ten days after initial
vaccination, the bump will turn into a pustule.
After two weeks the pustule will scab over and then fall off seven days
later. Under the scab will be a
permanent scar left from the immune response (Kiang, 2003). Because of the live nature of the vaccine,
the puncture site must be cared for from the day of vaccination until the scab
falls off (Tennyson, 2004). The site
will continuously shed live vaccinia for three weeks and can be spread to
others if not properly covered and maintained (“Smallpox Fact Sheet”, 2005).
The current smallpox vaccine is effective
for five to ten years and is successful in 95% of its recipients (Tennyson,
2005). Although protection drops after
the fifth year, the mortality rate of those contracting smallpox within ten
years of receiving the vaccine was only one percent. Even if infection occurs decades after last
successful vaccination, the effect on the body is greatly reduced (Kiang,
2003).
Complications
of Vaccination
The smallpox vaccination is considered by
the medical community to be safe for most people. Due to the live nature of the vaccinia virus
used in vaccination however, side effects, some common and some serious, do
exist. In most cases, those being
vaccinated for the first time (primary vaccinees) are most likely to react to
vaccinia. Considering that over 40% of
the United States population falls into this category, a revaccination campaign
would likely encounter many of these adverse outcomes (Chen, 2004).
Normal
Side Effects
Normal side effects are common in most
people after vaccination. The site of
inoculation typically becomes red and swollen, while glands of the armpit
become tender and enlarged after (“Reactions after Smallpox Vaccination”,
2002). Other typical side effects
include a localized rash, headaches, and a sore body (“Smallpox Fact Sheet”,
2005). In the past, one out of every
three recipients of the vaccine ran a fever and felt sick enough to stay home
for a day or two (“Reactions Smallpox Vaccination”, 2002). The length of illness is typically short,
while recovery is usually quick.
Serious
Side Effects
The serious side effects that may follow
vaccination are grouped into two categories: non-life threatening and life
threatening. It should be noted that
while serious side effects may occur in all groups of vaccinees, primary
vaccinees are ten times more likely to react adversely (Kiang, 2003). All figures below refer to those being
vaccinated for the first time.
According to studies conducted in 1968,
serious, but non-life threatening side effects typically occur in 1 out of
every 1,000 vaccinees (“Smallpox Fact Sheet”, 2005). These side effects may include a vaccinia
rash around the vaccination site, vaccinia rash present on the whole body, and
other non-lethal allergic reactions (“Reactions Smallpox Vaccination”,
2002). While these conditions are easily
treatable, more serious and potentially deadly side effects usually occur in
around 1 in 20,000 people (“Smallpox Fact Sheet”, 2005).
Four
main types of life threatening post-vaccine conditions have been described over
the years: eczema vaccinatum, progressive vaccinia, encephalitis, and
myopericarditis. Eczema vaccinatum is
most common, accounting for 75% of potentially life threatening cases. It occurs in people who have or have had a
history of eczema, spreading the vaccinia virus through the body by means of
the skin condition (Plaut, 2003). Progressive
vaccinia is a condition characterized by the spreading of live vaccinia to
other parts of the body (e.g. eyes, genitals).
As it leaves the vaccination site, it will often cause necrosis of
surrounding tissue and serious infection.
Progressive vaccinia is most common in vaccinees with compromised immune
systems. Encephalitis occurs in around 1
in 30,000 vaccinated persons, and is most common in children and infants. Due to the serious swelling of the brain
common in encephalitis, mortality rates are as high a 25% (Tennyson,
2004). Myopericarditis is an allergic
reaction, in this case to vaccinia, in which the heart muscle becomes inflames
and functions inefficiently, possibly leading to heart attack and death. Recently, the subject of post-vaccine
myopericarditis has been under intense scrutiny due to the high levels present
in the 2002 United States Department of Defense revaccination program
(Cassimatis, 2003). Of the 540,824 DoD
workers vaccinated, 62 developed some form of myopericarditis (1 in 8723)
(Eckart, 2004). Four people vaccinated
in the 2002 program later died from heart complications (Poland, 2005). It has been estimated that in a large scale
vaccination program, 2 people per 500,000 would die from one of these or other
serious complications due to the vaccinia virus (“Smallpox Fact Sheet”, 2005).
In
addition to the side effects of the vaccinee, the virus present in the smallpox
vaccine can also be accidentally spread to others. For up to one month, the vaccination site
will shed the virus, possibly infecting other household members (Lorich,
2004). In another very serious, though
disturbingly understudied condition known as fetal vaccinia, the virus is
spread to the fetus of a pregnant woman through the placenta. This can result in stillbirth or
miscarriage. It should be noted that
despite prescreening in the 2002 U.S. program, over 200 pregnancies were
discovered post-vaccine, with unknown consequences to the fetuses (Napolitano,
2004).
Due to the aforementioned side effects,
extensive screening must be completed in any smallpox vaccination
scenario. Those ineligible for the
vaccine include: those with skin conditions and weak immune systems (e.g. HIV,
chemotherapy), pregnant or possibly pregnant women, child under 12 months of
age, individuals with heart conditions, and those with certain blood disorders
(e.g. diabetes) (“Smallpox Fact Sheet”, 2005).
Conclusion/Recommendations
Smallpox
Vaccination Should be Voluntary in the 21st Century
In a world that’s seemingly growing more
dangerous each day, the chance of smallpox falling into the wrong hands could
be catastrophic. At the same time
however, state officials and citizens must realize that it is only a “chance”
that terrorists have the virus, not a certainty. When vaccination campaigns are used solely as
contingency measures, safety and side effects of vaccination become
paramount. According to the previously
mentioned data, out of the United States’ population of almost 300 million,
15,000 people would suffer life threatening side effects in a nationwide
vaccination campaign. Out of these
15,000, it is likely that 1,200 would die from complications. Due to this high number of likely smallpox
vaccine related deaths, a recommendation to always keep the vaccine completely
voluntary to the public, regardless of information obtained by the government
must be made. It seems to us unfair and
unreasonably risky to force citizens to risk their lives for an event that may
never come. Intense screening for those
who choose to be vaccinated, to help curb potentially deadly reactions and side
effects is also recommended. Finally,
medical, scientific, and public communities must be reeducated on the disease,
making future decisions on vaccination and contingency actions more educated
and prudent.
Glossary
ankyloblepharon
– sticking together of the eyelids
bifurcated
– divided into two parts (e.g. tongue of a snake)
cowpox
– original virus used in smallpox vaccines by Edward Jenner
ectropion – rolling outward of the eyelid
eczema
– noncontiguous skin condition characterized by red, itchy, scaly skin
encephalitis
– inflammation of the brain
immunogenic
– capable of producing an immune response in the body
myopericarditis
– inflammation of the cardiac muscle, causing a drop in blood flow
pustule
– swelling of the skin, usually filled with pus
vaccinia
– virus used in modern smallpox vaccines, closely related to smallpox
variola
– virus that causes smallpox
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