Uncertain Effectiveness and Limited Availability Would Likely Constrain the Use of Antivirals and Vaccines to Forestall the Onset of a Pandemic

The use of antivirals and vaccines to forestall the onset of a pandemic  would likely be constrained by their uncertain effectiveness and limited  availability. A targeted vaccine cannot be manufactured  until the pandemic strain has emerged and been identified. To achieve timely application, health authorities must be able to detect the  virus strain quickly through surveillance efforts and use this information  to administer or develop effective antivirals and vaccines. If an individual is diagnosed too late, antivirals may not be effective. According to HHS officials,  20 to 23 weeks are currently required from the detection of a pandemic  before a well-matched vaccine can be developed. Consequently, well- matched vaccines are likely to play little or no role in efforts to stop or  contain a pandemic, at least in its initial phases. In addition, only the number of outbreaks may be reported  rather than more specific information. While WHO has not  set a target for national antiviral stockpiles, it stated in 2007 that it is  unlikely that sufficient quantities of antivirals will be available in any  country at the onset of a pandemic. Some health authorities have suggested that increased seasonal  vaccination could play a limited role in forestalling the emergence of a  pandemic by limiting the opportunities for human and animal influenza  strains to combine and form a pandemic strain, but it is likely that the  limited availability of seasonal vaccination would limit its role in  forestalling an influenza pandemic. This limited vaccine production capacity would also limit the availability  of a pandemic vaccine in the event of a pandemic since the processes used  to manufacture seasonal and pandemic vaccines are similar and the  manufacturing would take place in the same facilities. Distribution and  administration capacities require plans, delivery networks, facilities  suitable for administering the drugs, trained personnel, and funding to get  antivirals to where they are needed and administer them promptly. Antiviral distribution networks are poor or nonexistent in some countries. U.S. Government and International Partners’ Efforts Are Under Way to Address Constraints on Use of Antivirals and Vaccines, but Certain Efforts Face Limitations

The United States, its international partners, and the pharmaceutical  industry are investing substantial resources in efforts to address the  uncertain effectiveness and limited availability of antivirals and vaccines. Efforts to make effective antivirals and vaccines more available include   (1) improving disease surveillance on an international scale in order to  monitor the evolution of influenza strains and the effectiveness of  antivirals and vaccines against those strains, (2) increasing global demand  for antivirals and vaccines to encourage production and spur research and  development, and (3) increasing global distribution and administration  capacity. Manufacturers are also working to  improve the effectiveness of vaccines to combat pandemic influenza  through such activities as developing pre-pandemic vaccines, examining  cell-based production technology, studying substances that can be added  to vaccines to improve effectiveness, and conducting research on vaccines  that would provide protection against multiple influenza strains. Research on and Development of Antivirals  Development of new antivirals is particularly important due to concern  over the emergence of antiviral-resistant influenza strains that could  render existing antivirals ineffective. WHO, countries, and pharmaceutical manufacturers have established  global and regional antiviral stockpiles to enhance the availability and  quick distribution of antivirals to the site of outbreaks. WHO is working to establish a pre-pandemic  vaccine stockpile. Although efforts are under way to increase antiviral and vaccine  manufacturers’ production capacity by building new facilities, these new  facilities are not expected to be ready to produce antivirals and vaccines  for several years. WHO provided comments via e-mail  and stated that the report was comprehensive and useful. HHS said  that we were assuming that antivirals and vaccines are the only tools  necessary to forestall a pandemic. In addition WHO has used the  word in describing its efforts to respond to a pandemic and our definition  is consistent with WHO’s use of the term. While we believe that these concepts are  consistent with our use of the term forestall when describing efforts to  respond to a pandemic in such a way as to avert, slow, mitigate, or change  the course of a pandemic, we have revised the report and defined forestall  to mean containing, delaying, or minimizing the impact of the onset of a  pandemic.
Why GAO Did This Study

Pandemic influenza poses a threat to public health at a time when the United Nations' World Health Organization (WHO) has said that infectious diseases are spreading faster than at any time in history. The last major influenza pandemic occurred from 1918 to 1919. Estimates of deaths worldwide if a similar pandemic were to occur have ranged between 30 million and 384 million people. Individual countries and international organizations have developed and begun to implement a strategy for forestalling (that is, containing, delaying, or minimizing the impact of) the onset of a pandemic. Antivirals and vaccines may help forestall a pandemic. GAO was asked to examine (1) constraints upon the use of antivirals and vaccines to forestall a pandemic and (2) efforts under way to overcome these constraints. GAO reviewed documents and consulted with officials of the Departments of State and Health and Human Services (HHS), international organizations, and pharmaceutical manufacturers. WHO commented that the report was comprehensive and useful. HHS stressed that vaccines and antivirals must be viewed in a larger context. State and HHS commented that the term "forestall" is ambiguous and misleading. However, GAO has used the word in a way that is consistent with WHO's use of the term.

What GAO Found

The use of antivirals and vaccines, two elements of the international strategy to forestall a pandemic, could be constrained by their uncertain effectiveness and limited availability. To use antivirals effectively, health authorities must be able to detect a pandemic influenza strain quickly through surveillance and diagnostic efforts and use this information to administer antivirals. The effectiveness of antivirals could be limited if they are used more than 48 hours after the onset of symptoms or by the emergence of strains resistant to antivirals. Unlike antivirals, vaccines are formulated to target a specific influenza strain in advance of infection. The effectiveness of vaccines in forestalling a pandemic could be limited because such a targeted pandemic vaccine cannot be developed until that strain has been identified. Due to the time required to identify the virus and develop and manufacture a pandemic vaccine--20 to 23 weeks according to HHS--such vaccines are likely to play little or no role in efforts to forestall a pandemic in its initial phases. The availability of antivirals and vaccines in a pandemic could be inadequate due to limited production, distribution, and administration capacity. WHO has stated that it is unlikely that sufficient quantities of antivirals will be available in any country at the onset of a pandemic. The distribution and administration capacity for antivirals and vaccines is limited in some countries by poor or nonexistent delivery plans and networks, a lack of facilities for administering the drugs, and small numbers of personnel trained to administer them. The United States, its international partners, and the pharmaceutical industry are investing substantial resources to address constraints on the availability and effectiveness of antivirals and vaccines. Efforts are under way to improve influenza surveillance, including diagnostic capabilities, so that outbreaks can be quickly detected. Increased demand and government support has led manufacturers to increase research into more effective antivirals and vaccines. Manufacturers are developing new antivirals to combat influenza. New methods for developing vaccines are being studied in order to reduce the amount of vaccine that is needed and to increase the number of strains against which it is effective. Pre-pandemic vaccines, which are formulated to target influenza strains that have the potential to cause a pandemic, are being developed. However, these vaccines may or may not be effective against the pandemic strain that ultimately emerges. To overcome limitations on the availability of antivirals and vaccines, manufacturers are working to increase production at existing facilities and build new facilities. To address constraints on the distribution and administration of antivirals, stockpiles are being established to allow faster delivery of antivirals to countries experiencing outbreaks. WHO is also working to establish stockpiles of pre-pandemic vaccines. Additionally, other efforts also face limitations. For example, increasing production capacity of vaccines and antivirals will take several years as new facilities are built and necessary materials acquired.