Reasonable Rascal
01-17-03, 22:08
DISEASE ERADICATION, VACCINATION, AND BIOTERRORISM
**************************************
A ProMED-mail post
Date: Sun, 12 Jan 2003 09:31:16 EST
From: Terrance J. O'Neill MD <terrence.oneil@medgrp.scott.af.mil>
In this day and age, when highly-transmissible diseases can become weapons to intimidate society, can any such illness ever again be considered "eradicated"?
In past decades, the idea of society being able to live at "virtually-zero-risk" once "the great plagues" were eradicated naturally suggested a strategy of stopping routine mass vaccination for such diseases when the low-but-nonzero probability of illness from the vaccine exceeded the risk of catching the native illness. This made sense so long as all members of society were willing to cooperate in making sure that the
disease stays eradicated.
Such a strategy, and the Public Health policies which that strategy drives, may well be a casualty of the advent of bio-terrorism. Within a very few years of the native disease being gone and routine vaccinations ceasing, herd immunity crashes, and society is now at-risk from re-introduction of the disease, whether as an augmented form of the attenuated strain, or through deliberate preservation of the wild-type organism, by those who stand to gain by societal disruption, both from the disease and from our efforts to
combat their actions.
Developing inventories of vaccine is an excellent idea, but if that inventory is the first step toward massive recalls and the cessation of routine mass immunization, then we are following antiquated public health policies which will expose us to the terrorist use of polio in the future, in the same way that fear of terrorist use of smallpox is affecting society today. Recent major-journal published articles have suggested that on-need immunization will result in less peacetime cases of vaccine complication as mass pre-immunization for smallpox. However, the statistics used to justify this approach do not properly take into account the probability that terrorists will deliberately disperse the [smallpox virus] at rapid-transportation hubs such as major airports, and such statistical arguments do not recognize that on-need vaccination requires a cordon-sanitaire approach to work in that setting. This coercion-enabled cordon-sanitaire implication is clearly built into the published national smallpox outbreak contingency plan. It would involve use of both civil and military forces authorized to detain exposed individuals who attempted to evade questioning, observation, and immunization (and by extension, using major force to do so). This might result in less statistical risk of vaccine complications before the outbreak, but the end-result of adopting such a policy would be to require a tactical approach to a real outbreak which would create unconscionable damage to society-at-large by striking at the fundamental level of trust of our citizens in their civil Government. In the end, it would be this, more than the disease itself, which would accomplish the ultimate goals of the terrorists. They would provide the tool to undermine our society, but we would wind up being the ones to employ those tools for them.
This is not a zero-risk universe. A modified but continued large-group immunization program for polio and all such high-transmissibility diseases must continue regardless of whether or not large-scale wild-type outbreaks are eradicated, and such a program must explicitly take into account that there will be members of society who suffer serious disabling complications of any immunization program. The greater risk is in trying to abandon such immunization programs based on short-sighted statistical-risk arguments and being faced with having to employ on-need tactics for bio-terrorist attacks which could wreck the very fabric of our social contract far more than the loss of life caused by the terrorists themselves.
--
TJO'Neil, MD, FACP
Chief of Medical Staff
375th Medical Group
Scott AFB, IL 62225
[This was written in response to ProMED-mail posting Poliovirus, inventory of stocks - USA 20021228.6146, but clearly reflects the bigger issues of disease eradication and vaccination strategies in today's environment, with concerns about intentional release of organisms causing diseases where transmission has been interrupted on a global scale.
In 2000, in a thread of postings related to the definitions of disease eradication vs. disease elimination, we published a short semantic debate featuring Dr. Philip Brachman and Dr. D.A. Henderson. In the final posting of this thread (ProMED-mail posting Eradication vs. elimination: defined, refined (03) 20000502.0665), Dr. Philip Brachman wrote "A recent reference, CDC -MMWR- Vol.48-Supplement 31 Dec 1999 "Global Disease Elimination and Eradication as Public Health Strategies," gives definitions on page 24 that I believe have been agreed upon as the correct definitions for these terms. Eradication is understood to mean that transmission no longer is occurring anywhere in the world, and all control/prevention measures can be stopped, while elimination means that there are areas in which the disease is no longer being transmitted, but since transmission is still occurring, control/prevention measures need to be continued, though possibly at a reduced rate but not totally stopped."
Dr. O'Neill's comments above cause one to reflect on the definition of disease eradication discussed at the Conference on Global Disease Elimination and Eradication as Public Health Strategies, held in Atlanta, GA, USA, on 23-25 Feb 1998, (the proceedings of which can be found at http://www.cdc.gov/mmwr/preview/mmwrhtml/su48tc.htm Can a disease be considered eradicated if all control/prevention measures are not stopped? Especially when the continuation of vaccination may lead to illness similar to that caused by the wild disease (generalized vaccinia, vaccine-associated poliomyelitis).
One still comes back to the basic decision-making process of weighing the comparative risks and benefits of public health strategies. In the case of vaccination policies, a key issue is comparing the risks of morbidity and mortality from the "natural" disease, versus the risks of morbidity and mortality from the vaccine. Dr. O'Neill is proposing that in today's environment, with heightened concerns about intentional release of organisms that would reintroduce "eradicated" diseases, we no longer have the luxury of considering cessation of vaccination against these diseases, and therefore should accept the associated morbidity and mortality from the vaccines. ProMED-mail has covered many of these issues in threads related to the current smallpox vaccination strategy development in the USA, and in discussions on the occurrence of outbreaks caused by circulating vaccine-derived poliovirus, and potential implications on vaccination policy (see prior posting threads listed below).
This begs the question: What is the expected annual morbidity and mortality associated with (1) an intentional release of an organism that has had worldwide transmission interrupted following cessation of vaccination compared with (2) continued vaccination annually? Cumulative comparative morbidity and mortality estimates can and should be prepared and factored into the decision-making process. - Mod.MPP]
**************************************
A ProMED-mail post
Date: Sun, 12 Jan 2003 09:31:16 EST
From: Terrance J. O'Neill MD <terrence.oneil@medgrp.scott.af.mil>
In this day and age, when highly-transmissible diseases can become weapons to intimidate society, can any such illness ever again be considered "eradicated"?
In past decades, the idea of society being able to live at "virtually-zero-risk" once "the great plagues" were eradicated naturally suggested a strategy of stopping routine mass vaccination for such diseases when the low-but-nonzero probability of illness from the vaccine exceeded the risk of catching the native illness. This made sense so long as all members of society were willing to cooperate in making sure that the
disease stays eradicated.
Such a strategy, and the Public Health policies which that strategy drives, may well be a casualty of the advent of bio-terrorism. Within a very few years of the native disease being gone and routine vaccinations ceasing, herd immunity crashes, and society is now at-risk from re-introduction of the disease, whether as an augmented form of the attenuated strain, or through deliberate preservation of the wild-type organism, by those who stand to gain by societal disruption, both from the disease and from our efforts to
combat their actions.
Developing inventories of vaccine is an excellent idea, but if that inventory is the first step toward massive recalls and the cessation of routine mass immunization, then we are following antiquated public health policies which will expose us to the terrorist use of polio in the future, in the same way that fear of terrorist use of smallpox is affecting society today. Recent major-journal published articles have suggested that on-need immunization will result in less peacetime cases of vaccine complication as mass pre-immunization for smallpox. However, the statistics used to justify this approach do not properly take into account the probability that terrorists will deliberately disperse the [smallpox virus] at rapid-transportation hubs such as major airports, and such statistical arguments do not recognize that on-need vaccination requires a cordon-sanitaire approach to work in that setting. This coercion-enabled cordon-sanitaire implication is clearly built into the published national smallpox outbreak contingency plan. It would involve use of both civil and military forces authorized to detain exposed individuals who attempted to evade questioning, observation, and immunization (and by extension, using major force to do so). This might result in less statistical risk of vaccine complications before the outbreak, but the end-result of adopting such a policy would be to require a tactical approach to a real outbreak which would create unconscionable damage to society-at-large by striking at the fundamental level of trust of our citizens in their civil Government. In the end, it would be this, more than the disease itself, which would accomplish the ultimate goals of the terrorists. They would provide the tool to undermine our society, but we would wind up being the ones to employ those tools for them.
This is not a zero-risk universe. A modified but continued large-group immunization program for polio and all such high-transmissibility diseases must continue regardless of whether or not large-scale wild-type outbreaks are eradicated, and such a program must explicitly take into account that there will be members of society who suffer serious disabling complications of any immunization program. The greater risk is in trying to abandon such immunization programs based on short-sighted statistical-risk arguments and being faced with having to employ on-need tactics for bio-terrorist attacks which could wreck the very fabric of our social contract far more than the loss of life caused by the terrorists themselves.
--
TJO'Neil, MD, FACP
Chief of Medical Staff
375th Medical Group
Scott AFB, IL 62225
[This was written in response to ProMED-mail posting Poliovirus, inventory of stocks - USA 20021228.6146, but clearly reflects the bigger issues of disease eradication and vaccination strategies in today's environment, with concerns about intentional release of organisms causing diseases where transmission has been interrupted on a global scale.
In 2000, in a thread of postings related to the definitions of disease eradication vs. disease elimination, we published a short semantic debate featuring Dr. Philip Brachman and Dr. D.A. Henderson. In the final posting of this thread (ProMED-mail posting Eradication vs. elimination: defined, refined (03) 20000502.0665), Dr. Philip Brachman wrote "A recent reference, CDC -MMWR- Vol.48-Supplement 31 Dec 1999 "Global Disease Elimination and Eradication as Public Health Strategies," gives definitions on page 24 that I believe have been agreed upon as the correct definitions for these terms. Eradication is understood to mean that transmission no longer is occurring anywhere in the world, and all control/prevention measures can be stopped, while elimination means that there are areas in which the disease is no longer being transmitted, but since transmission is still occurring, control/prevention measures need to be continued, though possibly at a reduced rate but not totally stopped."
Dr. O'Neill's comments above cause one to reflect on the definition of disease eradication discussed at the Conference on Global Disease Elimination and Eradication as Public Health Strategies, held in Atlanta, GA, USA, on 23-25 Feb 1998, (the proceedings of which can be found at http://www.cdc.gov/mmwr/preview/mmwrhtml/su48tc.htm Can a disease be considered eradicated if all control/prevention measures are not stopped? Especially when the continuation of vaccination may lead to illness similar to that caused by the wild disease (generalized vaccinia, vaccine-associated poliomyelitis).
One still comes back to the basic decision-making process of weighing the comparative risks and benefits of public health strategies. In the case of vaccination policies, a key issue is comparing the risks of morbidity and mortality from the "natural" disease, versus the risks of morbidity and mortality from the vaccine. Dr. O'Neill is proposing that in today's environment, with heightened concerns about intentional release of organisms that would reintroduce "eradicated" diseases, we no longer have the luxury of considering cessation of vaccination against these diseases, and therefore should accept the associated morbidity and mortality from the vaccines. ProMED-mail has covered many of these issues in threads related to the current smallpox vaccination strategy development in the USA, and in discussions on the occurrence of outbreaks caused by circulating vaccine-derived poliovirus, and potential implications on vaccination policy (see prior posting threads listed below).
This begs the question: What is the expected annual morbidity and mortality associated with (1) an intentional release of an organism that has had worldwide transmission interrupted following cessation of vaccination compared with (2) continued vaccination annually? Cumulative comparative morbidity and mortality estimates can and should be prepared and factored into the decision-making process. - Mod.MPP]