The benefits likely outweigh the risks’
The Centers for Disease Control and Prevention (CDC) temporarily should suspend its smallpox vaccination programs and conduct an evaluation and reassessment of the effort before vaccine is offered to larger groups of health care workers, a special panel of the Institute of Medicine (IOM) in Washington, DC, recommends.
"A pause is needed to evaluate the vaccination program’s processes and outcomes to date, and thus ensure that expanded vaccination continues to be as safe as possible for both vaccinees and their contacts," the IOM panel reported. ". . . A break in the course of the vaccination program may help prevent vaccinating potentially large numbers of additional volunteers [e.g., health care workers, traditional first responders, and others] less safely than in the first phase of vaccinations, without adequate time to implement or update safeguards [e.g., screening, training, and education] that would be appropriate to new types of vaccinees and their contacts."
The IOM smallpox review panel was formed at the request of the CDC, and the agency is expected to carefully consider its recommendations. Issued to the CDC May 27, 2003, the IOM report praises the agency for proceeding with deliberation and caution. The screening of potential vaccinees may have played a role in preventing several of the historically expected moderate-to-severe adverse events (e.g., eczema vaccinatum, progressive vaccinia) to the vaccine in 36,217 people vaccinated in the civilian program as of May 9, 2003.
"Also, it appears that vaccinee education on the risk of vaccinia transmission to contacts and measures taken to prevent it with appropriate bandaging and site care have worked well and may, in part, account for the absence of reported cases of vaccinia transmission from civilian vaccinees to either health care or personal contacts," the IOM noted. However, less welcome trends may emerge as the numbers increase and more occupationally diverse volunteers consider vaccination, the panel warned.
"The fact that by April 29, 2003, only 34% of vaccinees were included in the Smallpox Vaccine Adverse Event Active Surveillance System is an example of the additional work needed to help provide more data for a national view of the program," the report stated. "Some adverse events might not arouse concern on a state level, but aggregated nationally, new patterns could emerge." The recent fatal cardiac complications were unexpected adverse events, and there may be others. That is why it is important to ascertain whether the vaccine played a role in the cardiac events and rule out any other reasons for concern before vaccination is expanded to other populations, the panel advised.
In addition, the enactment of national smallpox vaccination compensation legislation is likely to remove a key barrier to vaccination, opening up the process to volunteers that heretofore may have reticent. "As this is a complex matter, the committee notes the need for additional clarification by CDC to the states on the provisions of the law, and for fact sheets or other explanatory materials for potential vaccinees," the IOM advised. Such fact sheets should explain the provisions of the legislation clearly and protections enacted and refer potential vaccinees to additional information sources.
"It is imperative that before continuing to expose individuals to a vaccine that is effective, but not without some risks, the national and state programs determine what level of pre-event vaccination is needed for preparedness," the IOM added. ". . . Although the initially expected civilian numbers have not been reached, pausing to evaluate remains an important component of the overall program of safely building smallpox preparedness. Also, by combining the safety data from both civilian and military vaccinations [totaling more than 460,000 vaccinees] a great deal can be learned, shared, and disseminated."
In advising the stoppage, the committee admitted such a move was not without risks. A pause could hinder preparedness and increase vulnerability to a smallpox attack. "However, given that the smallpox threat level, as it is publicly described, has not changed, the committee continues to believe that the benefits of the pause likely outweigh the risks," the IOM said.
Some areas already have begun offering the vaccine to a wider population of potential vaccinees. The committee recognized that it is important for states to finish the vaccination of volunteers to complete health care and public health response teams according to state plans.
Still the committee urged CDC to "facilitate the efforts of states that wish to pause to evaluate the process and outcomes of their vaccination efforts to date, and plan for next steps before deciding whether and when to begin vaccination of new personnel." The CDC should provide states with a target date when it expects to complete a revision of materials, data systems (adding new occupational categories, etc.), and guidelines. States that have identified a need for more vaccinated volunteers to carry out specific smallpox response functions will then be able to set their own timeline for vaccinating these new groups.
A pause would allow time for CDC and the states to modify vaccination plans, data systems, and materials in response to changing circumstances (i.e., a new population of potential vaccinees). It would be helpful for many states if these changes and revisions were made before they proceeded with vaccination, in part to avoid the difficulty of implementing changes midcourse.
The Centers for Disease Control and Prevention temporarily should suspend its smallpox vaccination programs and conduct an evaluation and reassessment of the effort before vaccine is offered to larger groups of health care workers, a special panel of the Institute of Medicine in Washington, DC, recommends.
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