story byWith the frequent mention of a possible smallpox threat creeping into our conversations, it is not surprising that many of us have concerns and questions.
Two experts at the University of Texas Medical School at Houston suggest this is a time for calm, caution and common sense when faced with news stories and water-cooler discussions about smallpox and the vaccine debate.
Facts, they agree, are an important tool all of us should use. “At issue is the credibility of the threat of a bio-terrorism attack using smallpox,” says Charles Ericsson, M.D., professor of internal medicine and head of the Clinical Infectious Disease department at UT Medical School at Houston. “We have a responsibility to the public to keep them informed about any public health threat and the federal government is not recommending mass vaccinations.”
“For the general population, the question is irrelevant at this time whether or not to be vaccinated,” explains Richard Bradley, M.D., assistant professor of emergency medicine. “While the U.S. government has a smallpox response plan among the steps to fight terrorism, only select numbers of health care providers who are first responders, will be offered the vaccine.”
While there is no treatment for the disease, the only prevention is vaccination. “A comforting fact,” says Ericsson, “is that exposed persons can be effectively protected as long as they’re vaccinated within three days of exposure.”
There is enough vaccine now to immunize everyone in the country,” adds Bradley.
Both UT doctors offer assurances by emphasizing that infectious control procedures work well and the current health care system can support massive efforts to manage a disease.
In 1967 the World Health Organization began a successful global campaign to eradicate the disease. The last naturally occurring case was in 1977 in Somalia.
“This is the only disease to ever be eradicated,” explains Bradley, “and it was a major public health victory after workers sought out people in the remotest corners of the world to treat this disease.”
Smallpox is a contagious, sometimes fatal, infectious disease characterized by high fever, aches and a chickenpox like rash.
“Individuals are not contagious until the onset of a rash and at this point they are usually too sick to carry on their normal activities, which means they are probably not out in the general population infecting people,” says Ericsson.
The rash of small red spots appears first on the tongue and in the mouth, but this can easily be missed. Then bumps appear on the face, followed quickly by the extremities, and the bumps develop into blisters. The whole evolution takes only one to two days.
The job of the smallpox vaccine is to help the body develop immunity to the disease.
The vaccine is made from a virus called vaccinia which is related to smallpox. The vaccine contains the “live” vaccinia virus, not a “dead” virus like other vaccines. This means that the vaccination site must be carefully cared for to prevent the virus from spreading. Because the vaccine does not contain the smallpox virus, it cannot give you smallpox.
The vaccine is not administered with a hypodermic needle and is not a shot. The vaccine is given usually in the upper arm with a two-pronged needle that is dipped into the vaccine solution. When removed, the needle retains a droplet of the vaccine. The needle is then used to prick the skin a number of times.
Three or four days after the vaccination, a red and itchy bump will appear at the vaccine site. The bump becomes a large blister that fills with pus and then drains. In the second week, the blister begins to dry and a scab forms. In the third week, the scab falls off and a small scar remains.
The vaccination offers a high level of immunity for three to five years, with decreasing immunity after that. If a person is vaccinated again later, immunity lasts even longer.
Historically, the vaccine has been effective in preventing smallpox infections in 95 percent of those vaccinated. Additionally, the vaccine has been effective in preventing, or substantially lessening, the infection when given within a few days of exposure.
Because vaccines were not produced after 1980, individuals under the age of 30 have no immunizations.
Those who are vaccinated for the first time have a stronger reaction than those who are revaccinated.
Usual side effects are mild and include a sore arm, fever and body aches. In a recent study, 75 of 200 subjects missed a day of work due to side effects like fever.
Some individuals are at greater risk for serious side effects that range from serious to life- threatening. This group includes those who have had a skin condition, those with weakened immune systems or those receiving treatment for cancer.
Previously, when one million people were vaccinated for the first time, between 14 and 52 individuals experienced potentially life-threatening reactions. Past experience suggested that out of the one million who received the vaccine, one or two would die.
Pregnant women should not get the vaccine or women who are breastfeeding. The non-emergency use of smallpox vaccine in children younger than 18 is not advised.
Right now, the best advice from these two UT doctors is to stay calm, keep informed and be prepared.
UPDATED: 2-17-2003
Editorial Board | Legal Disclaimer | Privacy & Security | Contact Us
©2000-2006 Office of Institutional Advancement, UT-Houston
Dr. Charles D. Ericsson is professor and clinical director of infectious diseases at the UT Medical School.
See Dr. Ericsson also at:
Dr. Richard Bradley is associate professor of emergency medicine at the UT Medical School.
See Dr. Bradley also at:
Tetanus booster for adults
Tetanus does not result from the rusty nail or whatever created the wound. The danger lies in the bacteria Clostridium tetani that lives in the soil or manure on that nail or gardening tool. When these spores get into a wound—deep or shallow—they can produce a potent toxin. Also called lockjaw, tetanus seriously affects the central nervous system and can be fatal.
Onset of symptoms can occur anytime from three days to three weeks. Call your health care provider if you have an open wound, particularly if:
Adults should have a tetanus booster shot every 10 years, known as the Td vaccine. It is a "2-in-1" vaccine that protects against tetanus and diphtheria. It contains a slightly different dose of diphtheria vaccine than what you received as a child. It can be given to anyone older than 7 years and is injected, usually into the arm.
Instead of the standard Td booster every 10 years, adults between the ages of 19 and 65 should receive Tdap one time in their adulthood to boost the immune system for pertussis, as well as tetanus and diphtheria.
Diphtheria, a contagious bacterial infection created that causes severe inflammation of the throat and larynx and can also affect the whole body. Pertussis or “whooping cough” is a serious bacterial infection that afflicted children and infants before vaccines were available. Adults may be infected later in life as their immunities wane. Neither of these infections are related to tetanus, but both vaccines are compatible and convenient to use with the tetanus booster.
