A Palimpsest of Pandemic Influenza Preparedness Plans

A palimpsest is a manuscript (usually written on papyrus or parchment) on which more than one text has been written with the earlier writing incompletely erased and still visible. It is a good word to describe the layering of pandemic influenza preparedness plans, each derived in part from earlier plans, extending from the World Health Organization (WHO) to the US Department of Health and Human Services (DHHS) to individual states and local health departments.

These plans are NOT paper documents stuffed into binders relegated to dusty shelves*; rather, they are plans undergoing continuous implementation. For example, the federal government, directed by leaders of agencies within the DHHS (such as Dr. Julie Gerberding, director of the Centers for Disease Control and Prevention), announced on February 24, 2005, that it is “getting ready to test a bird flu vaccine and stockpiling both vaccine and antiviral drugs as the threat grows that a deadly strain of avian influenza will begin spreading from Asia.”** Indeed, two million doses of vaccine are already being stored in bulk form for possible emergency use and to test whether it maintains its potency.

What is in these pandemic influenza preparedness plans? What is not in these plans? This essay introduces highlights of two important plans:

1. The WHO’s “Influenza Pandemic Plan” (1999) and

2. The DHHS “Pandemic Influenza Preparedness and Response Plan” (August 2004)

1. WHO’s 1999 Influenza Pandemic Plan***

The core of this plan is mercifully brief at 32 pages, not including annexes. The plan’s authors point out that the plan is not a “model plan;” rather it is a “document” that “has been prepared to assist medical and public health leaders to better respond to future threats of pandemic influenza. It outlines the separate but complementary roles and responsibilities for the WHO and for national authorities when an influenza pandemic appears possible or actually occurs.****

In a curious paragraph in the Executive Summary, the plan’s authors go on and on about the “rapid buildup of public fear” and [yes, you smart SEMP readers guessed it] “panic” about even “the possibility of a pandemic when a few cases of infection in humans with a new virus sub-type occur…as was seen in the US in 1976”***** (see Biot #177 for more on this at: http://www.semp.us/biots/biot_177.html). To better cope with such “false alarms” resulting from “intensive surveillance,” the good people at WHO defined a classification system that includes a series of “Preparedness Levels” that can be applied before the beginning of a pandemic is declared. The WHO authors write that the classification system should assist WHO to report on novel virus infections of humans and initiate precautionary responses, without creating unnecessary panic” [ouch, there’s that word again!] To their credit, WHO authorities accurately fingered a root cause of the US “swine flu” debacle of 1976: discovery of a novel influenza virus DOES NOT inexorably result in an influenza pandemic.

Here are the WHO Preparedness Levels: 1, 2, and 3. These three levels apply only to “Pandemic Phase 0.” What is Pandemic Phase 0? According to WHO, it is the “inter-pandemic period.” This is heady stuff because it cements in classificatory language the fact that pandemics are recurrent and that we can never let our guard down because even when there is no pandemic, there will be one soon enough. Following Phase 0 are Phases 1, 2, 3, 4, and 5—then back to Phase 0 again. Each phase (and preparedness level within Phase 0 only) is accompanied by specific response activities, which are described in the section on the DHHS pandemic influenza plan farther below.

WHO Phase 0:

• Preparedness level 1 is characterized by the appearance of a new influenza strain in a human case, and is validated by the first report(s) of isolation of a novel virus sub-type, without clear evidence of spread of such a virus or of outbreak activity associated with the new virus.

• Preparedness level 2 is characterized by a confirmed human infection, and is validated by confirmation that two or more human infections have occurred with a new virus sub-type, but where the ability of the virus to readily spread from person-to-person and cause multiple outbreaks of disease leading to epidemics is questionable.

• Preparedness level 3 is characterized by confirmation of human-to-human transmission. Clear evidence of inter-human transmission of the new virus sub-type must exist, e.g., secondary cases resulting form contact with an index case, with at least one outbreak lasting over a minimum two week period in one country.

WHO Phase 1: There are no more preparedness levels in Phase 1 because Phase1 means the onset of a pandemic has been confirmed. How is a pandemic confirmed? It is confirmed when WHO confirms that “a virus with a new hemagglutinin subtype (e.g., the “H5” in the H5N1 avian flu virus) compared to recent epidemic strains is beginning to cause several outbreaks in at least one country, and to have spread to other countries, with consistent disease patterns indicating that serious morbidity and mortality is likely in at least one segment of the population.”

WHO Phase 2: Characterized by regional and multi-regional epidemics.

WHO Phase 3: Characterized by the end of the first pandemic wave, meaning that “the increase in outbreak activity in the initially affected countries or regions has stopped or reversed, but outbreaks and epidemics of the new virus are still occurring elsewhere.”

WHO Phase 4: Characterized by second or later waves of the pandemic, which, based on experience, usually occur within 3-9 months of the initial epidemic in many countries.

WHO Phase 5: Characterized by end of the pandemic, usually after 2-3 years, and return to Phase 0.

The WHO document concludes with the following disclaimer: “We must also recognize that no pandemic plan prepared in advance will be 100% relevant or best for whatever situation nature eventually creates. Hence emphasizing the process and the issues for responding to a possible or actual pandemic may be more important than specific details, which may prove inapplicable to a new situation. Accordingly, that approach has been used in developing the guidelines presented here.” (p. 32)

2. The US DHHS “Pandemic Influenza Preparedness and Response Plan.”***

The core of the US pandemic influenza plan is 55 well-written pages, not including annexes. Annex 11, by the way, deals with “Lessons Learned from 1976 Swine Influenza Program,” much to the credit of the medical bureaucrats who created the plan. The core plan early on identifies the US DHHS seven “big guns” for preparing and responding to an influenza pandemic:

• Surveillance: Detecting novel influenza strains through clinical and virologic surveillance of human and animal influenza disease.

• Vaccine: Rapidly developing, evaluating, and licensing vaccines against the pandemic strain and producing them in sufficient quantity to protect the population; takes 6-8 months.

• Vaccination: Implementing a vaccination program that rapidly administers vaccine to priority groups and monitoring vaccine effectiveness and safety.

• Antiviral Drugs: Determine the susceptibility of the pandemic strain to existing influenza antiviral drugs and target use of available supplies to prevent influenza illness while awaiting vaccine.

• Measures to Contain Spread of Disease: Implement measures to decrease the spread of disease internationally and within the US guided by the epidemiology of the pandemic, e.g., infection control in hospitals to prevent infection among high-risk populations and health care workers.

• Local Community Preparedness: Assist state and local governments and health care system with preparedness planning in order to provide optimal medical care and maintain essential community services.

• Public communication effectiveness.

DHHS authorities have adopted--and expanded on--the WHO pandemic influenza classification system previously described. “Phase 0, the inter-pandemic phase, is divided into 4 (not 3) levels:

US Phase 0, Level 0: No recognized human infections caused by a novel influenza strain;

US Phase 0, Level 1: “New virus alert” with a case of human infection caused by a novel strain;

US Phase 0 Level 2: Two or more human cases but no documented person-to-person transmission and unclear ability to cause outbreaks;

US Phase 0 Level 3: “Pandemic alert” with person-to-person spread in the community and an outbreak in one country lasting for more than two weeks.

DHHS officials declare: “Progression from a New Virus Alert to a Pandemic Alert will be accompanied by response activities that include:

• intensified US and global surveillance;

• investigation of the virology and epidemiology of the novel influenza strain including collaboration with international partners on containment;

• vaccine development and clinical testing leading toward licensure of a pandemic vaccine;

• coordination with health departments and activation of local plans; and

• implementation of the communications plan which includes education of health care providers and the public.” (p. 5)

US Pandemic Phase 1: Confirmation that the novel influenza virus is causing outbreaks in one country, has spread to others, and disease patterns indicate that serious morbidity and mortality may occur.

US Pandemic Phase 2: Outbreaks and epidemics occur in multiple countries with global disease spread.

“Responses during Phase 1 and Phase 2 depend, in part, on the extent of disease internationally and in the US. Community-level interventions and travel restrictions may decrease disease spread. Once vaccine becomes available, immunization programs will begin. At this phase, antiviral prophylaxis and therapy targeted to maximize impact, local coordination of hospital and outpatient medical care and triage, and activation of emergency response plans to preserve community services also will occur. Federal agencies and personnel will support response activities, monitor vaccine effectiveness and adverse events following vaccination and antiviral drug use, conduct surveillance to track disease burden, and disseminate information.” (p. 5)

US Pandemic Phase 3: Signals the end of the first pandemic wave and may be followed by a second seasonal wave in Phase 4. Responses during Phase 3 include recovery, assessment and refinement of response strategies, ongoing vaccine production and vaccination and restocking supplies such as antiviral drugs. Greater vaccine availability, experience with and improved strategies for a pandemic response, and increased immunity to the pandemic strain should decrease the impact of the second pandemic wave.

US Pandemic Phase 4: Recurrent pandemic.

US Pandemic Phase 5: Pandemic burns out. Return to Phase 0.

Editor’s Note: Where are we in the course of the avian flu pandemic, according to the classification systems developed by WHO, used by DHHS, and presented in this Biot? By my assessment, we are well out of Pandemic Phase 0 and into Pandemic Phase 1 but not yet well into Phase 2. This assessment comes from the fact that avian flu H5N1 has killed 42 people in Thailand and Vietnam, but has not spread globally among humans (although it has among chickens).

Based on the February 24, 2005 announcement that DHHS is “getting ready to test a bird flu vaccine and stockpiling both vaccine and antiviral drugs as the threat grows that a deadly strain of avian influenza will begin spreading from Asia,”** DHHS appears to be inching into Phase 2. By any account, we are farther into this influenza pandemic than I supposed. The US has huge operations and experienced leaders in place to address the pandemic threat. The most important underlying philosophy in executing the response is a twofer:

1. Do good,

but

2. First, do no harm.

Comments? Please email moleary@semp.us.

Sources:

*P aper plan syndrome: “A syndrome characterized by the creation of anillusion of preparedness based on the mere completion of a written plan. One of the greatest impediments to preparedness is the belief that it can be achieved merely by the completion of a written plan. A bad plan is sometimes worse than no plan, because of the false sense of security it promotes. The paper plan syndrome also occurs when there is planning that is based on invalid assumptions. From: SEMP Glossary of Disaster Management, available online at:http://www.semp.us/htmlpages/glossaryp1.html.

**“Federal government prepares to test vaccines as bird flu warnings spread” by Randolph E. Schmid, Associated Press Writer, Washington, Feb. 24, 2005, available at: http://abcnews.go.com/Health/wireStory?id=526853.

***Two source documents:

1. World Health Organization “Influenza Pandemic Plan. The Role of WHO and Guidelines for National and Regional Planning.” April 1999, Geneva, Switzerland. Available at: http://www.who.int/csr/resources/publications/influenza/WHO_CDS_CSR_EDC_99_1/en/ Accessed July 6, 2005

2. US Department of Health and Human Services Core Document: Draft Pandemic Influenza Preparedness and Response Plan,” August 2004, National Vaccine Program Office, Office of the Assistant Secretary for Health, Washington, DC. Available at: http://www.publichealthlaw.info/HHS_PandemicFluPlan_Aug2004.pdf#search=
'pandemic%20influenza%20preparedness%20and%20response%20plan%20departmen
t%20of%20health%20and%20human%20services'.

****Note that WHO places “medical” leaders before “public health” leaders in this statement. This does not happen in the US influenza plan, where public health leaders come first, medical leaders second.

*****See SEMP Biot # 177: “The Flawed 1976 National “Swine Flu” Influenza Immunization Program” at: http://www.semp.us/biots/biot_177.html.

Additional sources:

1. WHO Avian Flu page available (but slow loading!) at: http://www.who.int/csr/disease/avian_influenza/en/.

2. SEMP Biot #117: “What Does Roz Lasker Know About Public Reaction to a Smallpox or Dirty Bomb Terrorist Attack?” at http://www.semp.us/biots/biot_117.html.

3. SEMP Biot #136 : “ Minnesota's Smallpox Vaccination Experience” at

http://www.semp.us/biots/biot_136.html

4. SEMP Biot #162 “What Is Swine Flu?” at http://www.semp.us/biots/biot_162.html.

5. SEMP Biot #149 “What Is Avian Flu” at http://www.semp.us/biots/biot_149.html).

6. SEMP Biot # 177: “The Flawed 1976 National “Swine Flu” Influenza Immunization Program” at: http://www.semp.us/biots/biot_177.html.