Smallpox Complications

Many view the events that occurred in the fall of 2001 as a wake-up call for the United States. Prior to 2001, support for preparations to address bioterrorist events was limited, and funding at the state and federal level was inadequate. But the events of 2001 brought a new public and political awareness to the threat of bioterrorism.

The past 18 months have seen a dramatic increase in both monetary and resource support for bioterrorism preparedness. It has also witnessed the inevitable tension between the desire to prepare for any and all potential events and concern over creating unnecessary fear and anxiety in the public and diverting scarce resources from other public health programs. Thus the U.S. Department of Homeland Security has urged Americans to create rooms sealed with plastic and duct tape to withstand a chemical attack even as Randall J. Larsen, director of the ANSER Institute for Homeland Security calls such safe rooms a waste of time.

Into this environment has come the national program to prepare for the possible use of smallpox as a bioterrorist weapon. On Dec. 13, 2002, President George W. Bush announced a plan to protect the United States by offering smallpox vaccination to ten million Americans. Healthcare workers, public health personnel, public safety personnel and Department of Defense employees would receive smallpox vaccinations over the next year, followed at some point by mass vaccination of the general public. This plan has generated substantial debate in the public health community. As in any measure to protect the public health from an infectious agent, the benefits need to be weighed against the risks.

The risks of mass vaccination were well studied in the 1960s, the last decade in which mass vaccination was practiced in the United States. For every million individuals vaccinated against smallpox for the first time in the 1960s, roughly 1000 experienced serious reactions, between 14 and 52 experienced potentially life-threatening reactions, and 1 to 2 died as a result of life-threatening reactions. It is estimated that serious reactions and deaths may be two to three times greater in the current era due to a much greater prevalence of those who are immune compromised, such as those with undiagnosed AIDS, individuals with transplanted organs and those receiving medications such as steroids. There is also the very real risk that vaccinated healthcare workers may inadvertently spread the vaccine virus to immune compromised patients.

The benefits of the national smallpox plan are more difficult to quantitate. The administration has repeatedly announced that it does not believe that a smallpox event is imminent, and that there are no hard data that any terrorist group actually possesses the virus. Debate has also centered on the most effective way to contain a smallpox event should we experience one. A number of public health officials, such as Dr. William Foege, former director of the Centers for Disease Control and Prevention (CDC), have speculated that a program to rapidly vaccinate contacts after an exposure might be more effective in controlling the spread of smallpox than a program aimed at vaccinating millions of Americans prior to an event. Dr. Foege, who was director of the CDC during the time that smallpox was finally eradicated, and J. Michael Lane, MD, MPH, former director of the smallpox eradication program, have stated that aggressive identification and vaccination of contacts was the strategy that ultimately eradicated smallpox as a naturally occurring illness, while mass vaccination had failed to produce such a result.

Due to concerns over the known side effects of the smallpox vaccine and potential secondary infections in hospitalized patients, a number of hospitals have been unwilling to participate in the national smallpox vaccination program. The numbers of healthcare workers and public health officials who have chosen to be vaccinated to date (25,645 as of March 21, 2003) are substantially below the target of several hundred thousand set by the administration. Editorials and opinion statements in scientific journals have supported both sides of the issue. Such debates are not new in the public health arena. Similar discussions have occurred regarding the control of polio hepatitis B, and meningococcal meningitis. What is new, however, are the political intrusions into this debate. In recent editorials and other opinion pieces in the media, such as a Washington Post editorial published Dec. 19, 2002, hospitals that chose to not participate in the national smallpox vaccination program have been criticized for questioning the president’s judgment. The authors of these pieces have found fault with scientific experts who presume to be able to evaluate the probability of a smallpox bioterrorism event. Some have even implied that to question decisions by the executive branch and federal agencies in the “war on terrorism” borders on being unpatriotic. Little legitimacy has been given to the concerns about the safety of the vaccine or whether the mass immunization strategy is really the most effective approach in a post event environment. It is curious that these same authors rarely express doubts about politicians who presume to be able to evaluate the scientific issues involved.

At present the debate continues. It is likely that the fate of the national smallpox vaccination program will be determined by events yet to unfold. If substantial numbers of vaccinees experience serious side effects, or if a number of secondary cases appear in family members or patients, it is likely that the program will never be widely accepted by the medical community. The CDC recently added additional restrictions on individuals who could receive vaccination after four experienced heart attacks, three of them with fatal outcomes. On the other hand, if another bioterrorist event occurs within the United States it is likely that many more healthcare workers, as well as members of the public, will seek to be vaccinated. Only time will tell which of these two scenarios will occur.

Bruce S. Ribner, M.D., M.P.H. is an Associate Professor of Medicine in the Division of Infectious Diseases at the Emory University School of Medicine in Atlanta, Ga.