Nov 2, 2005 (CIDRAP News) – US health officials focused largely on expanding supplies of vaccines and antiviral drugs today as they rolled out a lengthy plan for responding to a feared influenza pandemic that could kill an estimated 1.9 million Americans under worst-case assumptions.
The 300-plus-page HHS Pandemic Influenza Plan released by the Department of Health and Human Services (HHS) assumes that a pandemic flu virus would sicken about 30% of the population, or 90 million people. Depending on the virulence of the virus, anywhere from 865,000 to 9.9 million people could be hospitalized.
The release of the plan followed President George W. Bush's speech yesterday outlining his administration's strategy for countering the threat posed by the H5N1 avian flu virus. Bush asked Congress to provide about $7.1 billion for vaccines, antiviral drugs, surveillance, foreign aid, and emergency plans.
HHS officials said a pandemic would require a coordinated response from all levels of government along with individuals and the private sector. The plan calls for vastly improving the nation's capacity to produce flu vaccines and for stockpiling enough antiviral medication to treat 81 million people, or 25% of the population—a much higher goal than mentioned previously.
In a news briefing today, HHS Secretary Mike Leavitt said, "The good news is we have a vaccine [for H5N1] that's been developed by the National Institutes of Health. The bad news is we lack capacity to manufacture a vaccine in sufficient volumes and in the time frames necessary."
The vaccine now being tested is based on the current strain of the H5N1 virus, Leavitt noted. HHS is aiming to acquire enough doses of it to immunize 20 million people. It's likely that the virus would have to change before it can trigger a pandemic, but the current vaccine "would in fact still produce some level of immune response and would be the best opportunity we have to inoculate first responders and others who need protection," he said.
Ways to boost vaccine supply
The nation needs the capacity to produce enough doses of a pandemic-specific vaccine to immunize all Americans within 6 months of the start of a pandemic, Leavitt said. He said the new plans sets out three paths for reaching that goal: expansion of existing egg-based vaccine production, development of cell-based vaccine production, and the development of adjuvant, or dose-sparing, technology, which makes existing vaccine supplies go further.
Yesterday President Bush proposed spending $2.8 billion to develop cell-culture technology, $1.2 billion for buying doses of the existing H5N1 vaccine, and $1 billion for antiviral drugs.
"A primary tenet of our effort on vaccines is to make sure all are produced domestically," Leavitt said today. Only two companies, Sanofi Pasteur and MedImmune, currently make flu vaccines in the United States.
HHS hopes that cell-culture-based flu vaccines will be licensed and available within 4 or 5 years, said Dr. Bruce Gellin, director of HHS's National Vaccine Policy Office.
Federally sponsored trials of H5N1 vaccines with adjuvants will begin in January 2006, and results are expected in late spring or early summer, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID). The hope is that an adjuvant will reduce the amount of antigen needed per dose. In a recent trial of the H5N1 vaccine made by Sanofi Pasteur, the dose needed to trigger a protective immune response was much larger than the dose in seasonal flu vaccines.
Role of antivirals
Leavitt said antiviral drugs are an important part of pandemic preparedness but that it would take time to build a stockpile. "We have vendor representations that they can deliver . . . 20 million [treatment] courses by the fourth quarter of 2006 and up to 81 million courses by the summer of 2007," he said.
HHS officials previously had cited a goal of stockpiling enough oseltamivir (Tamiflu) to treat 20 million people. Currently the government has 2.3 million treatment courses, with another 2 million expected by the end of this year, officials have said.
Leavitt voiced reservations about the role of antiviral drugs even as he cited them as important. There is "no certainty that they'll be effective, and there's no capacity to change the antivirals to match the virus. As viruses mutate, they may change in a way that would cause the antiviral to not be effective." He also said there would be "distribution dilemmas."
The federal government will pay for most of the antiviral stockpile, but states will share the cost for part of it, Leavitt said in response to a question. "We've identified 44 million doses that will be paid 100% by the federal government," he said. Washington will pay for another 6 million doses for "deployment on a spot basis," and the federal and state governments will split the cost of the remaining 31 million doses, he added.
The plan also calls for spending $400 million to develop new and better antivirals, Leavitt said.
In introducing the HHS plan, Leavitt said it is "the medical and public health portion" of the pandemic strategy. "The plan also needs to include integrated plans from other parts of the federal government, but also plans from state and local governments and the private sector."
Making an analogy with computer systems, he said, "A virus is a network enemy. If it's approached by a mainframe response, we will not succeed."
Vaccines and antivirals are only two of six components of pandemic preparedness, Leavitt said. The others are international surveillance, domestic surveillance, communication, and state and local preparation.
Calling state and local preparation critical, he said, "We have recently been through hurricanes, and as large as those events were, they were constrained geographically. A pandemic is not. It's quite likely that a pandemic would be occurring in as many as a thousand or more locations around the country and many more beyond that around the world."
Possible pandemic scenarios
The HHS plan lists two sets of estimates of pandemic severity, one based on the moderate pandemic of 1957 and the other on the much worse pandemic of 1918. Both scenarios foresee about 90 million people falling ill and half of those seeking medical care, but the estimates differ after that. The moderate pandemic would cause an estimated 865,000 hospital cases and 209,000 deaths, while the severe event would bring 9.9 million hospital cases and 1,903,000 deaths. The estimates do not, however, allow for the potential effects of vaccines and antivirals.
The plan assumes that the illness rate would be highest in schoolchildren at 40% and would decline with age—a different picture than in 1918, when young adults were hit hardest. Planners also assumed that people would incubate the virus for 2 days after infection and would start shedding the virus half a day to a day before they actually felt sick. Each patient would be likely to spread the virus to two others.
In any given community, a pandemic outbreak would last about 6 to 8 weeks, but at least two waves of illness will be likely, the plan says. The seasonality of the pandemic can't be predicted.
If a pandemic begins to emerge elsewhere in the world, the United States, working with the World Health Organization and other countries, will try to stop it by "striving to arrest isolated outbreaks . . . whenever circumstances suggest that such an attempt might be successful," the plan says.
State and local responsibilities
Federal officials cautioned that the plan released today is just one part of a large network of interdependent plans. A number of activities must be anticipated and carried out on the state level, requiring states and communities to be prepared.
"Public health is and should remain a state and local function," Leavitt said.
William Raub, PhD, senior science adviser to Leavitt, said the federal plan should address some questions that states have had during their own planning processes. Almost to a state, major uncertainties included vaccines and antivirals, which the federal plan now covers.
However, state and local governments will need to cover myriad other topics, such as what recommendations to develop for slowing the spread of infection, social distancing, closing schools and public gatherings, and other preventive measures.
In that regard, Raub said, "We find the plans uneven."
In an effort to even them out, the federal plan details a broad mission: detect the earliest cases of disease, minimize sickness and death, and decrease social disruption and economic loss. HHS identifies several ways that it will support the states during an influenza pandemic, and then assigns state and local governments five overall tasks:
- Enhancing disease surveillance to ensure early detection of the first cases of pandemic flu in their jurisdiction;
- Distributing public stocks of drugs and vaccines and providing local physicians and hospital administrators with ongoing guidance on clinical management and infection control;
- Preventing local disease transmission using a range of containment strategies;
- Providing ongoing communication to the public about the response; and
- Providing psychological and social support services to emergency field workers and other responders.
Coordinating committees recommended
State and local governments should start by establishing a pandemic flu coordinating committee connecting a wide range of stakeholders, the document advises. That committee should create, review, and update a pandemic response plan that identifies the roles and responsibilities of state and local agencies, builds on existing plans for other emergencies, and addresses legal issues such as hospital staffing, patient care, and quarantine.
The federal plan emphasizes the importance of linking many players in a community. Specifically, it encourages state authorities to promote local pandemic task forces for community planning. For example, it's not enough that hospitals have their own plans: they depend on a number of groups, such as food suppliers, pharmaceutical suppliers, sanitation workers, and telephone companies in order to keep operating.
Rural areas may require special planning efforts because "a surge in pandemic influenza patients could force the closure of local outpatient healthcare clinics," the report noted.
The federal plan lays out 11 public health guidance areas for state and/or local governments to address: surveillance, laboratory diagnostics, healthcare planning, infection control, clinical guidelines, vaccine distribution and use, antiviral drug distribution and use, community disease control and prevention, management of travel-related risk of disease transmission, public health communication, and psychosocial workforce support services.
Legal review and, if necessary, updating of state laws and rules will help ensure preparedness for quarantine, isolation, and due-process issues. The planning checklist includes diverse items for state consideration. Among them: ensuring that a statute exists to allow quarantine/isolation for pandemic flu; conducting legal review of the feasibility of using faith-based organizations to assist people in isolation or quarantine; developing 24/7 on-call rotations for judges or hearing officers in local court systems to assure prompt due-process hearings for isolation/quarantine cases; and draft agreements for loaning facilities or services as needed for isolation/quarantine of people who cannot be confined to their homes (such as travelers or the homeless).
Community disease control and prevention
Recommendations about disease control and prevention include early actions to take during the period when potential cases or clusters of cases are identified. Individual-level containment measures in this period, which would presumably not cause undue strain on the public health and healthcare systems, would include such measures as patient isolation and identification, monitoring, and quarantining of contacts.
Planning for these actions will raise legal, logistic, and social challenges, the plan says. For example, quarantine is regulated by states, localities, and tribes, with regulations varying widely. In addition, in April 2005 influenza was added to the list of federally quarantinable diseases, meaning the HHS secretary can make and enforce regulations to prevent the spread of flu from foreign countries into the United States or between states. HHS can also aid local jurisdictions in enforcing their quarantines.
Other recommended planning steps include designating certain health offices, clinics, or special facilities for probable flu cases; setting up flu hotlines for information and triage; and preparing educational campaigns to explain how individual actions (eg, staying home from school when ill) and community actions (eg, closing schools) reduce disease spread. The messages will need to be tailored to the cultural and linguistic needs of local communities, the plan stresses.
When many cases and extensive transmission are occurring, state and local health departments could take measures to decrease social contact, such as quarantining groups or even whole communities and canceling public events. The plan points out that continuous monitoring of viral transmissibility, case distribution, and the nature and severity of illness would be necessary if such actions were taken.
The document says that community-wide, enforced quarantine is just one end of a spectrum of disease-containment strategies. Many other, less restrictive actions, such as voluntary home curfew, restrictions on gatherings, cancellation of public events, and "snow days" when everyone would be asked to stay home, could help slow disease spread.
The SARS episode demonstrated that the public will accept quarantine, the plan asserts. "Cooperation and acceptance was achieved through clear and comprehensive communication with the public about the rationale for use of quarantine" at that time, it states.
The SARS outbreak illustrated how fast an infectious disease can spread, but the spread of influenza would dwarf it, the plan asserts. One reason for this is the shorter incubation period (2 to 7 days for flu versus 7 to 10 days for SARS).
Measures to stem the spread of influenza into, out of, and within the United States range all the way from distributing travel alert notices, screening for and isolating ill travelers, and quarantining exposed passengers and crew, to closing mass transit systems and even prohibiting travel. The plan notes that the CDC operates 18 quarantine stations across the country to prevent introduction of infectious diseases. Each of these covers other points of entry within its region, and quarantine inspectors work with regulatory agencies to inspect arriving animals and cargo from outside the country.
HHS will help states and localities make decisions on what actions to take at what times during a pandemic, the plan says. The importance of continuous communication, collaboration, and coordination among different jurisdictions is stressed, as travel-related actions taken in one place will affect other places.
Public health communications
In the interpandemic period, flexible, sustainable communications networks should be built, according to the plan. Responsibilities for communications will be divided between HHS and state and local bodies. HHS's responsibilities will include providing materials through www.pandemicflu.gov, the Health Alert Network, and other resources for health professionals; international communications; and assuring consistent media messages across the federal government.
States and local areas will be responsible for such aspects as implementing and maintaining community resources like hotlines and Web sites and, in coordination with medical personnel, obtaining and tracking local case data to include in media messages. The plans stresses the need for consistent, accurate, and timely public health messages to support public health interventions and address social and economic changes caused by the pandemic.
Psychosocial support for the workforce
Several occupational groups that participate in pandemic response will have psychological and social needs: healthcare workers treating pandemic patients, public health workers trying to control disease spread, first-responder or nongovernmental organizations with employees assisting affected groups, service workers whose activities are essential to minimize social disruption, and family members of all of these workers. The plan calls for including psychosocial support services in emergency planning initiatives.
The tsunami relief effort in southern Asia showed that even seasoned responders can suffer uneasiness and distress; therefore, "Everything possible should be done to safeguard responders' physical and emotional health," the document states.
Amy Becker and Marty Heiberg contributed to this report.
Nov 2 HHS news release about the plan