Health Beat–Smallpox Vaccination: Assessing the Issues, Part 1

By Mary Jane Dittmar, Senior Assistant Editor

It is anticipated that smallpox vaccination programs for first responders will be in place around March 1. This date is tentative and may vary from state to state. State and local health departments will organize and implement the vaccination programs. The vaccination is voluntary.

Are you ready? Have you thought about whether you will be vaccinated? If you have made your decision, are you reasonably sure that it is based on a thorough examination of the primary issues involved? Have you, for example, carefully weighed the risks of the vaccination against the risks of the disease–not only for you, but also for those in your household, workplace, and community?

Have you determined who would be responsible for medical costs that would ensue should you or a member of your household experience an adverse reaction to the vaccine? Would your employer or workers’ compensation cover your costs? Would your health insurer cover the costs for you (if your employer or the state doesn’t) and your family member(s)?

What if you had to take a leave of absence from work? [Chief Jack Krakeel, of Fayette County (GA) Fire and Emergency Services, a member of the IAFC EMS Section and chairman of the IAFC Smallpox Vaccination Working Group, notes that it has been reported that up to one-third of the individuals who have been vaccinated took some type of sick leave from their jobs.] Would your employer (workers’ compensation) consider the illness as a line-of-duty “injury”?
The following information, summarized for this column, may help you to make or reevaluate your decision. Use it as a checklist. But become fully informed. Consult the references given at the end of this column and the Web sites of fire service organizations and government health agencies.

Potential for use of smallpox as a biological agent. According to the Advisory Committee on Immunization Practices (ACIP), “the use of smallpox virus as a biological weapon might be less likely than other biological agents because of its restricted availability; however, its use would have substantial public health consequences. A suspected case of smallpox would be considered a public health emergency.”

The disease. Smallpox (variola virus) is a serious, contagious, and sometimes fatal infectious disease that can cause a severe rash over the entire body and leave permanent scars. Symptoms, which begin 12 to 14 days after exposure, include high fever, malaise, and prostration with severe headache and backache, followed by the appearance of a rash that appears first on the oral mucosa, face, and forearms and then spreads to the trunk and legs.

The disease is transmitted person-to-person, through direct deposit of infective droplets on the nasal, oral, or pharyngeal mucosal membranes or the alveoli of the lungs from close, face-to-face contact. It can be spread indirectly through fine-particle aerosols or a fomite (an inanimate object or substance that can transmit infectious organisms from one individual to another) containing the virus. The patient is infectious until all scabs have separated, about three to four weeks after the onset of the rash. During the smallpox era (prior to 1960), the overall mortality rate was about 30 percent.

The vaccination. According to the ACIP 2001 document, vaccinia vaccine is a highly effective immunizing agent; it enabled the global eradication of smallpox. The last naturally occurring case of smallpox occurred in Somalia in 1977. The World Health Assembly certified in May 1980 that the world was free of naturally occurring smallpox. Vaccinations for all military personnel were discontinued in 1990. Because of concern that the smallpox virus may be used as a bioterrorism agent, the ACIP developed its recommendations for the smallpox vaccine.

The vaccine (Dryvax(r)–Wyeth Laboratories, Inc., Marietta, Pennsylvania) is a live-virus preparation of infectious vaccinia virus. It does not contain smallpox (variola) virus. Its efficacy has not been measured precisely during controlled trials, but epidemiologic studies demonstrate an increased level of protection against smallpox for from three to five years after primary vaccination and substantial, but waning, immunity can persist for more than 10 years. The Centers for Disease Control and Prevention (CDC) points out, however, that testing at the time the smallpox vaccine was used to eradicate the disease was not as advanced or precise as today; consequently, there may still be things to learn about the vaccine and its effectiveness and length of protection.

The vaccine can reduce symptoms or prevent smallpox if administered within the first days after initial exposure. Historically, the vaccine has been effective in preventing smallpox infection in 95 percent of those vaccinated.

Expected response to primary vaccination. The expected response to primary vaccination for smallpox in a nonimmune person who is not immunosuppressed (see “Contraindications”) is the development of a papule (a skin elevation, usually in conical shape) at the site of vaccination (two to five days after vaccination), which reaches its maximum size in eight to 10 days. The evolving pustule (small circumscribed skin elevation containing pus and having an inflamed base) dries and forms a scab, which separates within 14 to 21 days after vaccination, leaving a scar.

Most people who are vaccinated experience mild reactions, including a sore arm, fever, and body aches. Others may have reactions ranging from serious to life threatening. In the past, about 1,000 people for every one million vaccinated for the first time experienced serious, although not life-threatening, reactions, including a toxic or allergic reaction at the site of the vaccination or a spread of the vaccinia virus to other parts of the body through the blood.

The infected individual would be contagious from the time a rapidly spreading rash appears until the scabs from smallpox pustules have completely healed, which usually takes three weeks.

Based on past experience, it is estimated that one or two people in one million who receive the vaccine may die as a result. Careful screening of potential vaccine recipients is essential to ensure that those at increased risk (see “Contraindications”) do not receive the vaccine.

In Part 2: Contraindications for receiving the vaccine, Vaccination site care, Medical care and expenses, Resources.

References and Additional Resources

  • Advisory Committee on Immunization Practices (ACIP). “Vaccinia (Smallpox) Vaccine, Recommendations,” June 2001, http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5010a1.htm.
  • Centers for Disease Control and Prevention. “Public Health Emergency Preparedness & Response, Smallpox Vaccine Overview,” at www.cdc.gov. Public response hotline: 888-246-2675.
  • Centers for Disease Control and Prevention, “Summary of October 2002 ACIP Smallpox Vaccination Recommendations, updated Oct. 21, 2002; http://www.bt.cdc.gov/agent/smallpox/vaccination/acip-reds-oct2002.asp.
  • International of Fire Chiefs. A comprehensive guide on smallpox and related areas, including administrative considerations for the fire chief, is expected to be available at www.iafc.org around the end of January. Hard copies will be distributed to members thereafter.
  • International of Fire Fighters. “Smallpox Vaccination Program Guidance for Fire Fighters,” December 24, 2002; at www.iaff.org.

Additional Sites

http://www.bt.cdc.gov/agent/smallpox
http://www.bt.cdc.gov/agent/smallpox/vaccination/facts.asp
http://www.bt.cdc.gov/agent/smallpox/vaccination/contraindications-public.asp
http://www.bt.cdc.gov/agent/smallpox/index.asp
http://www.nlm.nih.gov/medlineplus/smallpox.html
http://www.who.int/emc/diseases/smallpox/factsheet.html
http://www.acponline.org/bioterro/index.html
http://www.bioterrorism.uab.edu/EIPBA/Smallpox/moreExtInfo.html.
http://www.vaccines.army.mil.
http://www.vhcinfo.org

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