Influenza Pandemic Planning

Ann Moen, Deputy ChiefInfluenza Branch

Centers for Disease Control & Prevention

Outline

• Pandemics—history and impact• Pandemic plans

– World Health Organization– US National Plan

• Overview of key planning and response topics

Pandemic Influenza

• Worldwide outbreak of a new strain of influenza to which virtually no one is immune

• New variant• Virulent• Transmissible from person-to-person

PostPost--1997 View of Transmission of 1997 View of Transmission of Avian Influenza A Viruses to HumansAvian Influenza A Viruses to Humans

HumanHumanvirusvirus

ReassortantReassortantvirusvirus

AvianAvianvirusvirus

DIRECTDIRECT

16 HAs16 HAs9 NAs9 NAs

Pandemics (& scares) of the 20th Century

• 1918 “Spanish Flu” (A/H1N1)– >500,000 deaths (U.S.) – >20 - 40 million worldwide– Young adults disproportionately affected

• 1957 “Asian Flu” (A/H2N2)– 69,800 deaths (U.S.)

• 1968 “Hong Kong Flu” (A/H3N2)– 33,800 deaths (U.S.)

• Pandemic Scares– 1976: Swine flu– 1977: Russian flu– 1997 and 1999: Avian flu (A/H5N1, A/H9N2)

Periods of Observed Circulation/DetectionOf Human Influenza A Viruses

H7

1918 1977 ‘99

H2H1

H5H9

H3

H1

1957 1968 ‘97 ‘03

Characteristics of a Pandemic

• Global in nature• Rapid person-to-person spread• Widespread panic, social disruption• Affects entire national infrastructure in short

timeframe• Can’t stockpile vaccine• Huge demands for information• Unpredictable

Estimated Impact of the Next Pandemic

• US pandemic impact estimates– 89,000 – 207,000 deaths– 314,000 – 733,000 hospitalizations– 18 – 42 million outpatient visits

• For perspective: US interpandemic impact estimates– 36,000 deaths– 200,000 hospitalizations– 5-10 million outpatient visits– $1-3 billion in direct medical costs

What can/should we do?

• PLAN!– Globally– Nationally– Locally

• Goals of a pandemic response– Limit morbidity and mortality– Decrease social disruption– Decrease economic loss

WHO’s International Roles for Pandemic Influenza

• Update WHO’s Pandemic Preparedness Plan • Provide pandemic preparedness guidance for countries at

different levels of economic development• Organize international teams for outbreak investigation• Coordinate international efforts for vaccine reference strain

development and production of pilot lots/vaccine• Coordinate with MoH when AI activity is identified• Declare when an influenza pandemic is imminent• Provide international guidelines for prevention and control

(very broad spectrum of guidelines)• Declare when a pandemic is over

Why was WHO Plan Revised ?

• To address public health risk from infection of animals

• To emphasize early (pandemic alert) phases when rapid intervention may limit spread

• To expand and differentiate WHO and National roles in each pandemic phase

• To add periodic risk assessment to provide a basis for phases

• To define criteria for downscaling phases

Purpose of New WHO Plan

• To inform and harmonize national and international pandemic preparedness/response

• To provide an overview of WHO and national actions prior to and during pandemic phases

• To provide an overview of national actions taken by country authorities (may be different by phase and for different countries)

• To provide framework for naturally occurring and intentionally released influenza viruses

• The WHO plan should is not a replacement for country-specific plans

• Phases in new WHO plan are related to, but different, from 1999; based on risk assessments

Updated in 2005

http://www.who.int/csr/disease/influenza/pandemic/en/

Common Framework for Pandemic Planning: WHO Phases

Interpandemic: No new influenza virus subtypes have been detected in humans

• Phase 1: virus with pandemic potential may be in animals; human risk low

• Phase 2: circulating animal viruses pose substantial human risk

Pandemic alert• Phase 3: human infection with new subtype, no P-to-P

spread• Phase 4: limited P-to-P spread; localized cluster only• Phase 5: larger localized cluster; transmissibility

increasingPandemic• Phase 6: increased and sustained P-to-P transmission in

general population

Structure of WHO Global Influenza Pandemic Preparedness Plan

(A matrix: phases x actions)

For each phase, specific objectives and actions to be taken by WHO, and those recommended for national authorities, are divided into five categories:

(1) planning and coordination;

(2) situation monitoring and assessment;

(3) prevention and containment;

(4) health system response; and

(5) communications.

Structure of WHO Global Influenza Pandemic Preparedness Plan

(A matrix: phases x actions)For each phase:WHO Objectives National Objectives

WHO Actions National Actions

phases 2-5:- affected

countries1

- unaffected countries

phase 6:- not yet affected- affected- subsided

1affected, or extensive travel/trade links

National Pandemic Planning Committees

• Policy Makers• Public Health Officials

– Lab– Epidemiology– Immunization

• Emergency Response/Management• Healthcare providers & institutions• Vaccine and antiviral manufacturers

national, state, local level

WHO ChecklistAn Excellent Tool

• Preparing for an emergency• Surveillance• Case investigation and treatment• Preventing spread of the disease in the

community• Maintaining essential services• Research and Evaluation• Implementation, testing and revision of the

national plan

GOOD NEWS!!!

• Spanish translations– WHO checklist for influenza pandemic

preparedness planning– WHO global influenza preparedness plan

• Available soon!!!

U.S. Pandemic Influenza Plans: National and State Plans

•U.S. Example and process•Pandemic planning topics

US National Plan Development

• 1978: Initial national plan drafted

• Ongoing efforts to enhance and revise plan

• 2004: core plan and annexes published in the Federal registrar for public comment

U.S. Plan: 2004 Edition

• Purposes – Define/recommend preparedness activities– Outline strategies/actions for increasing early

detection & effective response– Define the federal role/anticipated responsibilities– Provide guidance to health departments and

private sector for planning and response

Federal Role/Responsibilities

• Nationwide coordination of response– Coordinate surveillance– Conduct outbreak investigations

• In conjuction with WHO and state health departments– Develop lab tests and reagents– Develop vaccine strains – Determine vaccine priority groups and strategies – Assess measures to decrease transmission– Evaluate efficacy of response measures– Evaluate vaccine safety– ??? Vaccine purchase/distribution

• Contract for 2M doses– ??? Antiviral stockpiles - small stockpile

State and Local Pandemic Plans

• Purpose– Coordinate/implement local response

• Must address many practical issues– Vaccine distribution and administration– Antiviral distribution– Shortages of health care resources, hospital beds etc– Maintenance of essential community services

Key Planning & Response Topics: National and State Plans

• Surveillance• Vaccine/antivirals • Communications• Emergency Response• Research

Surveillance Considerations

• Strengthen global surveillance (early warning)– 113 National influenza centers in 83 countries– Develop in country networks for surveillance– Asian surveillance initiative

• Animal surveillance• Strengthen domestic interpandemic

surveillance • Plan for enhanced pandemic surveillance

Pandemic vs. Epidemic Surveillance

• Increased expectations…– Types of data– Amounts of data– Frequency of updates

• …by greater numbers/types of people– Public health professionals– Clinicians– Policy Makers– Public– Media

Pandemic Surveillance Considerations

• Expectation vs. Reality• Necessary back-up vs. too much redundancy • State/local needs vs. national needs• Seasonal surveillance as the foundation• Enhancements need to

– Increase frequency of reporting– Improve geographic and demographic coverage– Provide data at more local level– Increase amount of detail captured in some

components

Preparing for Disease Surveillance During Pandemic*

• Outpatient, hospitalization, and mortality data– Daily data updates from at least a subset of reporters– National, state, county level analysis of activity– Year-round

• Hospitalization and mortality data– Case level basic demographic data – All influenza associated hospitalizations and deaths – Nationwide

* Early draft (not cleared) proposed enhancements

Preparing for Virologic Surveillance During Pandemic*

• Specimen level data transmitted electronically – Daily updates – National, state, county level analysis of activity

• Type & subtype as many viruses as possible during interpandemic and early pandemic– Report unusual subtypes or unsubtypeable viruses to CDC ASAP

• Be prepared to process specimens from suspect cases– PCR in BSL2– Culture HPAI (e.g. H5N1, H7N7) in BSL3– Ship to CDC if proper facilities not available

• Prepare for substantial increase demands for testing • Year-round

* Early draft (not cleared) proposed enhancements

Vaccine Considerations

• Influenza vaccine--cornerstone of prevention– Interpandemic – Pandemic

• Vaccine shortages likely– Especially early

• Two doses of vaccine may be needed• Target population likely to be everyone

– 295+ million people – If 2 doses needed: ~600 million vaccine doses

Influenza Vaccine Produced for the U.S. Market

Year Number of Doses Produced

1999 77.2 M2000 77.9M2001 87.7M2002 93 M2003 83M2004 60M

Data provided by the U.S.-licensed influenza vaccine manufacturers

General Vaccine Preparedness Activities

• Enhance influenza vaccine coverage during the interpandemic period– Improves manufacturing capacity– Prepares delivery & administration infrastructure

• Enhance pneumococcal vaccine coverage• Develop plans

– Equitable distribution– Identify priority groups– Address regulatory hurdles (licensing & testing)

Federal Vaccine PreparednessActivities

• Secure supply by encouraging new manufacturers and new approaches

• Prepare seed strains• Evaluate/license vaccine• Develop/implement vaccine policy

– Procurement, distribution, administration– Government versus private sector role– Liability protection

• Monitor vaccine safety (post-licensure)

Antiviral Drug Considerations

• Only alternative to vaccine • 4 drugs with important differences

– Side effects– Approved uses (types of use and ages) – Resistance patterns– Cost

• Treatment vs. prophylaxis• Major supply issues• Stockpiling is very expensive

General Antiviral Preparedness Activities

• Develop usage recommendations– Treatment vs. prophylaxis– Target populations for each use

• Consider increasing antivirals in Strategic National Stockpile– Very limited amount currently stockpiled

Communications Considerations

• Demand for information will be high• Deliver clear, consistent, timely information

– Multiple target audiences/languages– Advance preparation of written materials– Communications infrastructure– Redundant systems– Secure communications– Involve partners

General Communication Preparedness Activities

• Establish and maintain a strong communications infrastructure

• Provide accurate, consistent, rapid, and complete information and guidelines– State and local public health– Health care providers– public

Emergency Response Considerations

• Covers many issues– Maintaining essential services – Healthcare system surge capacity

• Many similarities to other disasters/outbreaks• Unique challenges of a pandemic

– Affects human infrastructure– Widespread areas affected simultaneously– Local health services overwhelmed– Need to maintain vital services– Demand could last 6-8 weeks in each community

General Emergency Response Preparedness Activities

• Develop plans & recommendations – Maintenance of essential services

– Increasing bed capacity

– Utilization of non-traditional sites for medical care

– Provision of home health care and other community-level support

Research Considerations (1)

• Influenza biology and epidemiology– Genetic markers for transmissibility and virulence– Populations at highest risk (inform vaccine/AV

priorities)– Effectiveness of measures to decrease transmission

• isolation, quarantine, travel restrictions– Effectiveness of other of response measures

Research Considerations (2)

• Vaccine and antiviral development– Cell-culture based vaccine development– Reverse genetics and traditional reassortment to

prepare pandemic seed-strains– Clinical trials: candidate vaccines, dose, adjuvants– Antiviral development/research

CDC A/H5N1 Health Advisories

• Multiple advisories distributed via health alert network and Epi-X– 2004: Jan, Feb, June, August– 2005: February

• Feb 2005: CDC recommends maintaining enhanced surveillance by state & local health departments, hospitals, and clinicians to identify patients at increase risk for avian influenza A(H5N1) as described in earlier notices

HAN Guidance: Surveillance Criteria (1)

Testing for avian influenza A (H5N1) is indicated for hospitalized patients with:

– Radiographically confirmed pneumonia, acute respiratory distress syndrome (ARDS), or other severe respiratory illness for which an alternate diagnosis has not been established

--AND--– History of travel within 10 days of symptom onset to a

country with documented H5N1 avian influenza in poultry and/or humans

HAN Guidance: Surveillance Criteria (2)

Testing for avian influenza A (H5N1) should beconsidered on a case-by-case basis for hospitalized or ambulatory patients with:

– Documented temperature of >38°C (>100.4°F)--AND--

– Cough, sore throat, and/or shortness of breath--AND--

– History of contact with poultry or a known or suspected human case of influenza A (H5N1) in an H5N1-affected country within 10 days of symptom onset.

HAN Guidance: Virus Isolation

• Culturing of HPAI A (H5N1) must be done under BSL 3 laboratory conditions with enhancements– Controlled access double door entry with change

room and shower, use of respirators, decontamination of all wastes, and showering out of all personnel

– Labs working on these viruses must be certified by USDA

– CDC recommends virus isolation on suspect patients specimens ONLY if stringent enhanced BSL 3 conditions can be met

HAN Guidance: PCR & Antigen Detection

• PCR testing of specimens from suspect A (H5N1) cases can be done under standard BSL 2 conditions in a Class II biological safety cabinet

• Commercial antigen detection testing can be conducted under standard BSL 2 conditions used to test for influenza

HAN Guidance: Specimens to Send to CDC

• Specimens from persons meeting surveillance criteria should be sent to CDC if:– The specimen tests positive for influenza A by PCR or

by antigen detection testing--OR--

– PCR assays for influenza are not available at the state public health laboratory

• CDC also will accept specimens from persons meeting the surveillance criteria if:– The specimen tests negative by influenza rapid

diagnostic testing --AND--

– PCR assays are not available at the state laboratory

Continued Threats

• H5N1, H9N2, H7N7• HPAI viruses continue to be isolated from farms• Widespread in poultry in Asia• Poultry depopulation minimizes risk, but not

uniformly practiced• Evidence of greater frequency of transmission to

humans

General Pandemic Planning Summary

• Need planning at global, national, st/local levels– Vaccine production, procurement, distribution, liability

issues & antiviral drugs– Communications, surge capacity, response

• The best defense is to strengthen the capacity to handle seasonal influenza– Improved surveillance/detection– Increase vaccination rates/vaccine production– Vaccine delivery infrastructure

• Need on-going research• Integrate with BT, SARS, other disaster planning

efforts