Smallpox
Given the uncertainty of our current political
climate, people are increasingly concerned about
the threat of biological or chemical acts of
terror. One of the major concerns to arise after
September 11, 2001, was the threat of a terrorist
attack in which smallpox would be used against
the U.S. population. Would the United States
be prepared in the event of such an attack? Would
there be enough of the vaccine to treat everyone?
What kind of side effects would result from this
vaccine? These and many other questions have
been asked regarding smallpox.
The following are questions and answers, which
have been asked most frequently concerning smallpox.
What is smallpox?
Smallpox is a contagious disease caused by a virus. Although the disease of
smallpox has been eradicated worldwide through successful vaccination and
treatment programs, the virus is stored in research centers at sites in the
US and Russia. There is concern that a some other countries may also have
the virus.
What are the symptoms of smallpox?
The incubation period for smallpox is approximately 7 – 17 days. The
symptoms include high fever, fatigue, severe headache, backache, malaise, a
rash, delirium vomiting and diarrhea, vomiting and diarrhea and excessive bleeding.
The rash begins as red bumps and changes first to vesicles (blister-like) on
the red rash and then to pustules that subsequently develop a scab, which falls
off after a three weeks, leaving a pitted scar. The rash is usually seen first
on mucous membranes (mouth, nose, throat, conjunctivae), face, and forearms.
It spreads quickly to the trunk (chest, abdomen, back) and legs.
Is smallpox treatable?
At the present, treatment for smallpox is ‘supportive’ meaning
it is aimed at helping to maintain body functions in someone who is infected
until that person recovers from the disease. There is also research going on
using cidofovir, an antiviral agent currently being used to treat cytomeglovirus
(CMV) in patients who are immunocompromised.
What can be done if someone is exposed to
smallpox?
If the smallpox vaccination is given within 1 – 4 days after exposure
to the disease, the smallpox vaccination may prevent illness or lessen the
degree of the illness associated with the disease. Once symptoms have begun,
however, current treatment is limited to supportive care only.
In the event that someone is diagnosed with
smallpox, s/he will be isolated immediately (quarantined)
from contact with other people. In addition,
all individuals who had face-to-face contact
with the infected person will have to be isolated,
vaccinated, and closely monitored for the development
of smallpox. Emergency measures will be implemented
immediately to protect a broader segment of the
population. Further guidance will come from The
Centers for Disease Control (CDC) and other federal
and local health agencies.
Is the smallpox vaccine available today?
If yes, can I get it?
When smallpox was declared eradicated over three decades ago, the World Health
Organization decided that further vaccinations were unnecessary.
Given the potential threat of a terrorist attack
involving smallpox, a three phase vaccination
program is now being instituted by the Federal
Government. In mid-December of 2002, vaccinations
were begun for the military, including the Commander-in-Chief,
President George Bush. As of January 24, 2003,
the vaccine was offered to “first responders” like
health care providers, police, and firefighters
who have chosen to participate at this time.
The vaccine is also being made available to selected
researchers. The third phase will involve providing
vaccinations for the general public and is not
anticipated to begin until 2004. The Centers
for Disease Control has stated that they have
enough vaccine stockpiled to vaccinate the entire
US population, if there were to be an outbreak
of the disease. In the event that this does happen,
the CDC and the Public Health Service are prepared
to vaccinate part or all of the US. population
within 10 days.
Is the smallpox vaccination dangerous?
The vaccine used to protect against smallpox is called “vaccinia (smallpox)
vaccine.” It does not contain smallpox virus, but it does protect against
the development of smallpox, when properly administered. It has not been routinely
used in the U.S. since 1972. Should the vaccine be administered in the future
to control an outbreak, complications may occur that are mild, serious, or
life-threatening. When the vaccination was last administered, an estimated
one or two people per million, receiving the vaccine for the first time ever,
died from complications. Almost all were children or immunocompromised individuals.
Serious complications occurred in 15 per million.
Because vaccinia vaccine is a live-virus vaccine,
it can be passed on to other unvaccinated individuals
in close contact with the vaccinated individual.
The unvaccinated individuals having the virus
passed to them run the same risks of complications
as the vaccinated individuals.
Who should not receive the smallpox vaccination?
In the absence of a national emergency, the vaccine is contraindicated for
people with eczema, (active or inactive), dermatitis, HIV/AIDS, autoimmune
diseases like systemic lupus, anyone undergoing cancer treatment with radiation
or chemotherapy, anyone receiving immunosuppressive medications for other
conditions, pregnant or nursing women, anyone under the age of 18, and persons
in close contact with anyone for whom the vaccination is not advisable.
How is the smallpox vaccine administered?
The technique for giving the smallpox vaccination is unique. A tiny, two-pronged
needle (bifurcated) is dipped into the vaccine and this bifurcated needle
is used to make multiple punctures in the skin. Three punctures are suggested
for someone who has never been vaccinated, 15 punctures for people who have
been previously vaccinated. The person giving the vaccination must inspect
the site for the appearance of blood to confirm that the skin was pierced.
The site is then covered with a dry bandage and must remain bandaged until
the scab from the vaccination falls off the skin, usually after three to
four weeks.
What makes smallpox different from other
live virus vaccinations, such as the one children
receive for measles?
Other vaccines are placed under the surface of the skin in muscle or soft tissue
by a needle. The smallpox vaccine, when it “takes”, causes a lesion
on the skin, which contains live virus. The concern is the virus can be transmitted
to other parts of the body or even to another person; therefore, it is imperative
that strict hand hygiene and appropriate bandage disposal measures are followed.
How soon does the smallpox vaccination become
effective?
Most people begin to produce antibodies within three to five days of a vaccination
and full protection within two to three weeks.
What does the vaccination look like?
Once the vaccination is completed, a bandage is placed over the site. The site
goes through a series of changes from a reddened area to developing a pustule
(a blister with pus in it) to a dry scab. The live virus is present until
the site is completely healed. The scab itself must be discarded appropriately.
The healing process can take up to four weeks.
What are the usual side effects from the
vaccination?
The reactions most often reported are soreness or itching of the vaccination
site, fever, tiredness, and lymph adenopathy (swollen glands) under the arm.
The vaccine can cause a number of more serious problems that were referred
to above.
Is there help for someone who experiences
a bad reaction to the vaccination?
Vaccine Immune Globulin (VIG) was developed in the 1960s. It is produced from
plasma obtained from recently vaccinated donors and contains antibodies against
the vaccinia virus. It has been helpful in some individuals with serious complications
in the past. VIG is currently stored at the CDC and can be made available on
short notice, if necessary.
There are some antiviral medications under investigation
that may prove useful, but more work needs to
be done to establish their efficacy.
Am I still protected if I already received
the vaccination?
The vaccination has not routinely been given in the U.S. for 3 decades. There
is little, if any, antibody protection provided by vaccinations received that
long ago.
If you have questions concerning smallpox vaccination,
call PENNHealth at 1-800-789-PENN (7366) and
ask to speak to the Penn Travel
Medicine staff.
Special thanks to AE Mica, BA, RN and the Penn
Travel Medicine Staff for their contributions
to this article.
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