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R Bruce Aylward

Publications and source records attributed to R Bruce Aylward.

17 recordsLinked to original sources
PubMed2006

New strategies for the elimination of polio from India.

The feasibility of global polio eradication is being questioned as a result of continued transmission in a few localities that act as sources for outbreaks elsewhere. Perhaps the greatest challenge is in India, where transmission has persisted in Uttar Pradesh and Bihar despite high coverage with multiple doses of vaccine. We estimate key parameters governing the seasonal epidemics in these areas and show that high population density and poor sanitation cause persistence by not only facilitating transmission of poliovirus but also severely compromising the efficacy of the trivalent vaccine. We analyze strategies to counteract this and show that switching to monovalent vaccine may finally interrupt virus transmission.

Child↗
PubMed2006

Interrupting poliovirus transmission -- new solutions to an old problem.

Since the launch of the Global Polio Eradication Initiative (GPEI) in 1988, knowledge as to the nature of circulating polioviruses and the challenges to their interruption has increased tremendously, particularly during the period 2000-2005. By January 2006, however, the systematic application of the standard polio eradication strategies, combined with recent refinements, had reduced the number of countries with ongoing transmission of indigenous wild polioviruses to just four (Nigeria, India, Pakistan, and Afghanistan), the lowest ever in history. In addition, only 8 of the 22 areas that had been re-infected by wild poliovirus in 2003-2005 still required large-scale 'mop-up' activities and circulating vaccine-derived poliovirus (cVDPV) outbreaks were being readily addressed. This progress, despite new challenges late in the GPEI, was greatly facilitated by a range of solutions that included two new monovalent oral polio vaccines (mOPVs), new and robust international standards for polio outbreak response, and renewed political commitment across the remaining infected countries.

Humans↗
PubMed2006

A vision of a world without polio: the OPV cessation strategy.

Once the eradication of wild poliovirus has been confirmed, the public health benefits of routine immunization with OPV will no longer outweigh the burden of disease either due to paralysis caused by OPV (vaccine associated paralytic polio), or by outbreaks caused by circulating vaccine-derived polioviruses. The eventual cessation of OPV use in routine immunization programmes worldwide will become necessary to assure a lasting eradication of polio. As the world moves towards polio eradication and its certification, preparations are therefore being intensified for OPV cessation, and the risk management framework for safe OPV cessation is being put in place. The framework includes bio-containment of all known poliovirus and potentially infected substances, development of an international stockpile of oral polio vaccine, ensuring a mechanism for continued global surveillance and response for polio after eradication has been certified, and national policies if countries decide to continue vaccinating with inactivated polio vaccine (IPV). It is ironic that the vaccine on which the world has depended for polio eradication will itself become a risk to eradication once the transmission of wild poliovirus has been interrupted. Final preparations for the eventual global and simultaneous cessation of OPV will require the same level of international cooperation and coordination that has brought the world to the verge of polio eradication.

Global Health↗
PubMed2006

Risks of paralytic disease due to wild or vaccine-derived poliovirus after eradication.

After the global eradication of wild polioviruses, the risk of paralytic poliomyelitis from polioviruses will still exist and require active management. Possible reintroductions of poliovirus that can spread rapidly in unprotected populations present challenges to policymakers. For example, at least one outbreak will likely occur due to circulation of a neurovirulent vaccine-derived poliovirus after discontinuation of oral poliovirus vaccine and also could possibly result from the escape of poliovirus from a laboratory or vaccine production facility or from an intentional act. In addition, continued vaccination with oral poliovirus vaccines would result in the continued occurrence of vaccine-associated paralytic poliomyelitis. The likelihood and impacts of reintroductions in the form of poliomyelitis outbreaks depend on the policy decisions and on the size and characteristics of the vulnerable population, which change over time. A plan for managing these risks must begin with an attempt to characterize and quantify them as a function of time. This article attempts to comprehensively characterize the risks, synthesize the existing data available for modeling them, and present quantitative risk estimates that can provide a starting point for informing policy decisions.

Bioterrorism↗
PubMed2006

Risk management in a polio-free world.

Inherent in the decision to launch the Global Polio Eradication Initiative in 1988 was the expectation for many people that immunization against poliomyelitis would eventually simply stop, as had been the case with smallpox following its eradication in 1977. However, the strategies for managing the risks associated with a "polio-free" world must be continuously refined to reflect new developments, particularly in our understanding of the live polioviruses in the oral poliovirus vaccine (OPV) and in the international approach to managing potential biohazards. The most important of these developments has been the confirmation in 2000 that vaccine-derived polioviruses (VDPVs) can circulate and cause polio outbreaks, making the use of OPV after interruption of wild poliovirus transmission incompatible with a polio-free world. A comprehensive strategy has been developed to minimize the risks associated with eventual OPV cessation, centered on appropriate long-term biocontainment of poliovirus stocks (whether for vaccine production, diagnosis, or research), the controlled reintroduction of any live poliovirus vaccine (i.e., from an OPV stockpile), and appropriate use of the inactivated poliovirus vaccine (IPV). Although some aspects of this risk management strategy are still debated, there is wide agreement that no strategy would entirely eliminate the potential risks to a polio-free world. The current strategy for risk management in a polio-free world will continue to evolve with better characterization of these risks and the development of more effective approaches both to reduce those risks and to limit their consequences should they occur.

Disease Outbreaks↗
PubMed2006

Development and consideration of global policies for managing the future risks of poliovirus outbreaks: insights and lessons learned through modeling.

The success of the Global Polio Eradication Initiative promises to bring large benefits, including sustained improvements in quality of life (i.e., cases of paralytic disease and deaths avoided) and costs saved from cessation of vaccination. Obtaining and maintaining these benefits requires that policymakers manage the transition from the current massive use of oral poliovirus vaccine (OPV) to a world without OPV and free of the risks of potential future reintroductions of live polioviruses. This article describes the analytical journey that began in 2001 with a retrospective case study on polio risk management and led to development of dynamic integrated risk, economic, and decision analysis tools to inform global policies for managing the risks of polio. This analytical journey has provided several key insights and lessons learned that will be useful to future analysts involved in similar complex decision-making processes.

Centers for Disease Control and Prevention, U.S.↗
PubMed2005

The human story.

Explore the source record for details and available documents.

Communicable Disease Control↗
PubMed2005

Policy. OPV cessation--the final step to a "polio-free" world.

The 20-year, U.S. $4 billion-dollar international effort to eradicate wild polioviruses now includes monovalent oral poliovirus type 1 vaccine (mOPV1), which was first given to 40 million children in India in April 2005. As this vaccine is being introduced to eliminate some of the last poliovirus reservoirs, the Global Polio Eradication Initiative is planning for the eventual synchronized worldwide cessation of the routine use of all oral poliovirus vaccines (OPVs) because of their capacity to cause, rarely, outbreaks of paralytic poliomyelitis. This Policy Forum reviews the feasibility and implications of eventually stopping the use of live polio vaccines.

Drug Utilization↗
PubMed2005

Polio eradication: mobilizing and managing the human resources.

Between 1988 and 2004, the Global Polio Eradication Initiative grew to become the largest international health effort in history, operating in every country of the world. An estimated 10 million health workers and volunteers have been engaged in implementing the necessary polio supplementary immunization activities (SIAs) on a recurring basis, and at least 35,000 well-trained workers have been conducting polio surveillance. A combination of task simplification, technological innovations and adaptation of strategies to fit local circumstances has allowed the Initiative to use a wide range of workers and volunteers, from both inside and outside the health sector, to deliver the polio vaccine during SIAs and to monitor progress in virtually every area of every country, regardless of the health infrastructure, conflict, geography and/or culture. This approach has required sustained political advocacy and mass community mobilization, together with strong management and supervisory processes. Non-monetary incentives, reimbursement of costs and substantial technical assistance have been essential. Given the unique features of eradication programmes in general, and polio eradication in particular, the implications of this approach for the broader health system must continue to be studied if it is to be replicated for the delivery and monitoring of other interventions.

Community Health Planning↗
PubMed2005

Can we capitalize on the virtues of vaccines? Insights from the polio eradication initiative.

Twenty-five years after the eradication of smallpox, the ongoing effort to eradicate poliomyelitis has grown into the largest international health initiative ever undertaken. By 2004, however, the polio eradication effort was threatened by a challenge regularly faced by public health policymakers everywhere-misperception about the benefits and risks of vaccines. The propagation of false rumors about oral poliovirus vaccine safety led to the reinfection of 13 previously polio-free countries and the largest polio epidemic in Africa in recent years. With deft management of such challenges by local, national, and international health authorities, poliomyelitis, a disease that threatened children everywhere just 2 generations ago, could soon be relegated to history like smallpox before it.

Africa↗
PubMed2004

Framework for evaluating the risks of paralytic poliomyelitis after global interruption of wild poliovirus transmission.

With the interruption of wild poliovirus transmission globally, the need for new policies to deal with the post-certification era will rapidly arise. New policies will be required in four areas: detection and notification of circulating polioviruses; biocontainment of wild, vaccine-derived and attenuated strains of poliovirus; vaccine stockpiles and response mechanisms; and routine immunization against polioviruses. A common understanding of the potential risks of paralytic poliomyelitis in the post-certification period is essential to the development of these policies. Since 2000, there has been increasing international consensus that the risks of paralytic poliomyelitis in the post-certification era fall into two categories: those due to the continued use of the oral poliovirus vaccine (OPV) and those due to future improper handling of wild polioviruses. The specific risks within both categories have now been defined, and an understanding of the frequency and potential burden of disease associated with each is rapidly improving. This knowledge and clarity have provided a framework that is already proving valuable for identifying research priorities and discussing potential policy options with national authorities. However, this framework must be regarded as a dynamic tool, requiring regular updating as additional information on these risks becomes available through further scientific research, programmatic work, and policy decisions.

Certification↗
PubMed2003

Global health goals: lessons from the worldwide effort to eradicate poliomyelitis.

The Global Polio Eradication Initiative was launched in 1988. Assessment of the politics, production, financing, and economics of this international effort has suggested six lessons that might be pertinent to the pursuit of other global health goals. First, such goals should be based on technically sound strategies with proven operational feasibility in a large geographical area. Second, before launching an initiative, an informed collective decision must be negotiated and agreed in an appropriate international forum to keep to a minimum long-term risks in financing and implementation. Third, if substantial community engagement is envisaged, efficient deployment of sufficient resources at that level necessitates a defined, time-limited input by the community within a properly managed partnership. Fourth, although the so-called fair-share concept is arguably the best way to finance such goals, its limitations must be recognised early and alternative strategies developed for settings where it does not work. Fifth, international health goals must be designed and pursued within existing health systems if they are to secure and sustain broad support. Finally, countries, regions, or populations most likely to delay the achievement of a global health goal should be identified at the outset to ensure provision of sufficient resources and attention. The greatest threats to poliomyelitis eradication are a financing gap of US 210 million dollars and difficulties in strategy implementation in at most five countries.

Communicable Disease Control↗