New York State Nurses Association
REPORT: December 2002
Smallpox Vaccinations Are Coming!
Federal Agency Recommends Inoculations for Healthcare Workers
by Nancy Webber
It looks as if at least some nurses in New York state will have to decide whether to be vaccinated for smallpox within the next year, as the state prepares for a possible bioterrorism attack.
Thanks to aggressive immunization efforts in the 20th century, the world's last documented case of smallpox was in 1977. Routine smallpox vaccinations in the U.S. were halted in 1972. But samples of the virus were kept in research facilities in the U.S. and the Soviet Union, and there is some evidence that some of this stockpile has been obtained by terrorist organizations. If the smallpox virus was spread through a population with no immunity to the disease, up to 30% would die, as estimated by the Centers for Disease Control and Prevention (CDC).
The CDC's Advisory Committee on Immunization Practices (ACIP) recommended in October that about a half million hospital workers in the U.S. be immunized. These workers would be equipped to respond to any outbreak of smallpox. As Report went to press, a final decision was yet to be announced. But some kind of vaccination program is probably inevitable, perhaps as early as January 2003.
"It's going to happen," said Karen Ballard, director of NYSNA's Practice and Governmental Affairs Program. "As soon as there is enough vaccine immune globulin (VIG) to treat severe reactions, we will see healthcare workers vaccinated in New York. It makes public health sense to be prepared for an outbreak."
Who will be vaccinated?
ACIP proposes that all acute care facilities establish smallpox healthcare teams made up of physicians, nurses, and support personnel from the emergency department, intensive care, and other subspecialties. Each team might include up to 45 people, depending on the size of the facility, and each hospital would need at least two teams.
Everyone on the team would be vaccinated against smallpox and trained to provide care to smallpox patients. Even nurses who were vaccinated prior to 1972 would probably need to be re-vaccinated because the effectiveness of the vaccine drops after ten years. The proposal specifies, however, that vaccinations will be voluntary.
Reactions can be severe
The smallpox vaccine carries a higher risk of serious side effects than other vaccinations. Unlike flu shots, smallpox vaccinations use a live cowpox virus (vaccinia) that is similar to the smallpox virus (variola) and thus provides immunity to smallpox. If the vaccination "takes," a skin eruption occurs at the site of the inoculation. Over the course of three weeks, the so-called "Jennerian vesicle" eventually forms a scab and heals over. The person will also typically experience itching at the vaccination site, swelling and tenderness of the axillary lymph nodes, fever, and malaise.
In a small number of cases, reactions can be much more severe. A national survey done in 1968 found that 63 out of every million people who received primary vaccinations had such reactions. A survey of physicians in 10 states during the same period found a much higher adverse event rate of 823 per million patients. Researchers say the lower rate should be considered minimal. These reactions do not include cases of smallpox. The vaccine does not use the smallpox virus and an individual cannot get smallpox from a vaccination.
The most common types of major complications are accidental infection, generalized vaccinia, and progressive vaccinia.
Accidental infection occurs when the vaccinia virus is introduced into other parts of the body, such as the eyes or mouth, usually caused by failure to wash the hands after touching the vaccination site.
Generalized vaccinia occurs when widespread lesions appear apart from the vaccination site, usually accompanied by fever. Extreme cases can be fatal, especially in children or those with suppressed immune systems.
Progressive vaccinia is characterized by a spreading necrosis at the vaccination site, with metastatic lesions in later stages.
Severe reactions may be treated with vaccine immune globulin (VIG). According to the CDC, there is enough VIG available to treat 600-800 patients. More is being produced.
Patients who contract vaccinia may also develop encephalitis, with children under a year old at a higher risk. In the 1968 national survey, there were 2.3 cases of encephalitis per million.
People with histories of eczema, atopic dermatitis, or other skin conditions are more prone to severe reactions. Those with HIV/AIDS are also at increased risk, as are any individuals whose immune systems are suppressed.
Vaccinia can be spread by contact
The national survey done in 1968 found that 20% of those who developed vaccinia didn't acquire it from their own vaccination. They got the disease from someone else's vaccination.
For three weeks following a smallpox vaccination, the vaccinia virus is shed from the inoculation site and may be spread to others through contact. This fact is significant, because healthcare workers daily come in contact with patients who are most susceptible to infection.
"There are issues for nurses to consider, both personally and professionally," said NYSNA's Karen Ballard. "During that three-week period, they must carefully follow procedures to prevent contact transmission of vaccina, not only to their patients, but also to members of their families who are not vaccinated. Handwashing will be critical."
Citing the 1968 data, health experts say the chance of infection from someone else's vaccination is low, and that close contact is necessary for transmission. ACIP is recommending that healthcare workers keep the vaccination site covered with two layers of dressings (absorbent gauze covered by a semi-permeable bandage) until the scab falls off. The vaccination site must be checked daily and individuals must wash their hands after touching the vaccination site.
Forty-year-old data may not accurately predict what would happen in 2003, however. The population is vastly different. Almost everyone under the age of 30 has no immunity to smallpox. Atopic dermatitis, a significant risk factor for severe reactions, has become more prevalent in children over the past 30 years. There are more people with suppressed immune systems due to HIV/AIDS or various medical treatments. And, an estimated 8-12% of healthcare workers are sensitized to latex and are likely to have dermatitis.
A likely vaccination scenario:
ACIP did not recommend that nurses and other workers be placed on leave after being vaccinated, stating that the close contact required for transmitting the vaccinia virus is unlikely in a healthcare setting. Nurses may need to take some sick leave, however, because of the discomfort and fever commonly associated with the vaccine.
It is likely that healthcare facilities will vaccinate the smallpox teams in phases to minimize the effect on staffing levels. ACIP also recommends that nurses who have previously been vaccinated should be included in the first phase, because they are less likely to have severe reactions.
Anyone who is considering being vaccinated for smallpox should be screened for:
* history of atopic dermatitis, eczema, Darier's disease or household members with these conditions
* current skin conditions such as burns, impetigo, varicella zoster, herpes, severe acne, or psoriasis
* pregnancy-pregnant women (or those trying to become pregnant) should not be vaccinated because of a potential risk of fetal vaccinia
* HIV/AIDS infection-available on a voluntary and confidential basis.
"Nurses should be informed about the risk factors and evaluate the risks both for themselves and their families," said Ballard. "It is clear, however, that all workers on a smallpox response team must be vaccinated."
NYSNA staff working on issues
NYSNA staff are working closely with the state Department of Health and other agencies involved in establishing a possible vaccination program. The association also has received an emergency preparedness grant from the state to provide education and training to nurses who may be administering vaccinations to healthcare workers or the general public.
NYSNA is preparing an online continuing education course on smallpox that will soon be available at www.nysna.org.
Detailed information can also be found at the CDC Web site, www.bt.cdc.gov/agent/smallpox/index.asp.