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On April 29, 2009, the World Health Organization (WHO) raised its influenza (“flu”) pandemic
alert level to Phase 5, one level below declaring that a global influenza pandemic was underway.
According to WHO, “the declaration of Phase 5 is a strong signal that a pandemic is imminent
and that the time to finalize the organization, communication, and implementation of the planned
mitigation measures is short.”
The WHO has increased the pandemic flu alert level in response to the spread of a new strain of
influenza A subtype H1N1 virus. First identified in Mexico in March 2009, the novel flu strain
has quickly spread to the United States, where, as of April 29, there are 91 confirmed cases of
illness, including one death. Additional cases have been confirmed in several other countries.
The new flu strain was initially dubbed “swine flu” because it contained genetic material from flu
strains that normally circulate in swine. However, there has been no evidence to date that pigs are
involved in the transmission of this virus. There have been concerns that the term “swine flu” has
had unwarranted trade implications for swine and pork products, among other concerns. On April
30, 2009, WHO began referring to the new strain as influenza A(H1N1).
Federal agencies have adopted a pandemic response posture, under the overall coordination of the
Secretary of Homeland Security. The Obama Administration has requested $1.5 billion in
emergency supplemental appropriations to address the threat, and congressional committees in
both chambers have convened emergency hearings to assess the situation.
This report provides an introduction to the situation regarding the potential of a global human
influenza pandemic caused by the new H1N1 flu strain; a brief chronology of events; a discussion
of key actions taken and authorities invoked by the WHO and the U.S. government; information
about key U.S. government pandemic flu planning documents; and sources for additional
information about the situation as it unfolds. This report will be continually updated to reflect
unfolding events.

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Introduction ..................................................................................................................................... 1
Brief Chrononology (2009) ............................................................................................................. 3
Key Official Actions........................................................................................................................ 5
International Actions ................................................................................................................. 5
WHO: Determination of Influenza Pandemic Phase .......................................................... 5
WHO: International Health Regulations............................................................................. 7
WHO: Travel and Food Safety Guidance ........................................................................... 8
U.S. Government Actions ......................................................................................................... 8
Department of Homeland Security (DHS) Leadership Designation................................... 8
HHS Determination of a Public Health Emergency ........................................................... 8
FDA Emergency Use Authorization ................................................................................... 9
CDC and State Department Travel Notices ........................................................................ 9
Emergency Supplemental Appropriations .......................................................................... 9
Naming the Virus Strain.................................................................................................... 10
U.S. Pandemic Influenza Planning Documents............................................................................. 10
Key Information Sources............................................................................................................... 12

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Figure 1. WHO Influenza Pandemic Phases ................................................................................... 7

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Table 1. WHO Influenza Pandemic Phases ..................................................................................... 6

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Author Contact Information .......................................................................................................... 12

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On April 29, 2009, the World Health Organization (WHO) raised its influenza (“flu”) pandemic
alert level to Phase 5, one level below declaring that a global influenza pandemic was underway.
According to WHO, “the declaration of Phase 5 is a strong signal that a pandemic is imminent
and that the time to finalize the organization, communication, and implementation of the planned
mitigation measures is short.”1
The WHO has increased the pandemic flu alert level in response to the spread of a new strain of
influenza A subtype H1N1 virus. First identified in Mexico in March 2009, the novel flu strain
has quickly spread to the United States, where, as of April 29, there are 91 confirmed cases. Most
of the cases have been mild, but there have been five hospitalizations, including one death.
Additional non-fatal cases have been confirmed in Austria, Canada, Germany, Israel, New
Zealand, Spain, and the United Kingdom. Case counts are rising daily.
The new influenza strain responsible for the outbreak is an apparent reassortment of several
existing strains of influenza A subtype H1N1 virus, including strains typically found in pigs,
birds, and humans. The Centers for Disease Control and Prevention (CDC) reports that the
symptoms and transmission of the novel H1N1 flu from person to person are much like that of
seasonal flu. Laboratory testing of the new strain indicates that the antiviral drugs oseltamivir
(Tamiflu) and zanamivir (Relenza) are expected, in most cases, to be effective in treating illnesses
that result from this new strain.
The new flu strain was initially dubbed “swine flu” because it contained genetic material from flu
strains that normally circulate in pigs. However, there has been no evidence to date that the
outbreak arose from human exposure to pigs. Also, WHO and other health officials have stressed
that there is no risk of infection from consumption of pork. There have been concerns that the
term “swine flu” has had unwarranted trade implications for swine and pork products, among
other concerns. On April 30, 2009, WHO began referring to the new strain as influenza A(H1N1).
An influenza pandemic occurs when a novel flu strain emerges and spreads across the globe,
causing serious illness among humans. For that to happen, the virus must have the following three
features: it must be genetically novel so that there is a lack of preexisting immunity; it must be
pathogenic (i.e., capable of causing illness in humans); and it must be easily transmitted from
person to person. WHO, in consultation with experts in member countries, monitors global
movement of flu strains among human populations, and has developed a scale for monitoring
pandemic risk. The scale consists of five pre-pandemic phases with increasing incidence of
animal and then human illness and transmission, and a sixth phase that represents a full-blown
human pandemic, with sustained viral transmission and outbreaks in most or all regions of the
world. Historically, flu pandemics have occurred in multiple waves before subsiding.
As a result of the rapid spread of the new H1N1 strain, WHO raised its official pandemic alert
level from Phase 3, where it had been for several years because of the threat of H5N1 avian flu, to
Phase 4 on April 27, and then to Phase 5 on April 29. Phase 3 means that a novel flu strain is
causing sporadic cases of small clusters of disease but is not sufficiently transmissible to sustain

1 World Health Organization (WHO), Pandemic Influenza Preparedness and Response: A WHO Guidance Document,
April 2009, p. 32, http://www.who.int/csr/disease/influenza/pipguidance2009/en/index.html.
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community-level outbreaks. Phase 4, by contrast, signals that human-to-human transmission of
the virus is sufficient to sustain community-level outbreaks. Raising the alert level to phase 5
means that there is sustained community-level transmission in two or more countries within one
WHO region, and that a pandemic may be imminent. Table 1 describes the phases of a flu
pandemic, as defined by WHO.

Influenza Defined
Influenza (“flu”) is a respiratory illness that can be transmitted from person to person. Flu viruses are of two main
genetic types: Influenza A and B. Influenza A strains are further identified by two important surface proteins that are
responsible for virulence: hemagglutinin (H) and neuraminidase (N).
Seasonal flu circulates each year in the winter in each hemisphere. The dominant flu strains in global circulation
change from year to year, but most people have some immunity; infection can be fatal. CDC estimates that there are
about 36,000 deaths from seasonal flu each year, on average. Vaccines are made each year based on predictions of the
strains that are most likely to circulate in the upcoming flu season.
Avian flu (“bird flu”) is caused by viruses that occur naturally among wild birds, and that may also affect domestic
poultry. In 1997 a new “H5N1”strain of avian flu emerged in Asia, and has since caused millions of deaths among
domestic poultry, and hundreds of deaths in humans. Health officials have been concerned that this strain could cause
a human pandemic, and governments around the world have carried out a number of preparedness activities,
including vaccine development and stockpiling, and planning for continuity of services.
Swine flu occurs naturally and may cause outbreaks among wild and domestic swine. People do not normally get
swine flu, but each year CDC identifies a few isolated cases of human flu that are caused by flu strains typically
associated with swine.
Pandemic flu is caused when a novel strain of human flu (i.e., one that spreads from person to person) emerges and
causes a global outbreak, or pandemic, of serious illness. Because there is little natural immunity, the disease is often
more severe than is typical of seasonal flu.
(Adapted from HHS, “Flu Terms Defined,” http://www.pandemicflu.gov. For more information about pandemic flu,
see “Understanding Pandemic Influenza” in CRS Report RL33145, Pandemic Influenza: Domestic Preparedness Efforts.)

In response to the situation, the Secretary of Homeland Security, Janet Napolitano, has assumed
the role of Principal Federal Official, coordinating federal response efforts. On April 26, Charles
E. Johnson, then the Acting Secretary of Health and Human Services (HHS), who is responsible
for coordinating the public health and medical response to the incident, declared a public health
emergency. Among other things, the declaration authorized the Food and Drug Administration
(FDA) to issue Emergency Use Authorizations (EUAs), permitting certain unapproved uses of
Tamiflu and Relenza (such as in very young children), as well as the use of an unapproved
diagnostic test for the new flu strain.
CDC has released these antiviral drugs, as well as respiratory protection devices and other
medical supplies, from the Strategic National Stockpile (SNS), to help states respond to the
outbreak. CDC reports that it has released to state health officials one-quarter of the 50 million
treatment courses of Tamiflu and Relenza stockpiled in the SNS. CDC also has activated its
Emergency Operations Centers to coordinate the agency’s response to the outbreak, and has
issued an advisory recommending travelers to postpone all non-essential travel to Mexico. Border
control agents are visually inspecting incoming travelers from Mexico, questioning them about
symptoms and recent illnesses, and isolating and testing those who appear to be sick.
Administration officials are resisting calls to implement more aggressive measures such as
closing the U.S.-Mexico border, noting that the new flu strain is already in the United States and
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that the focus of mitigation strategies is on where U.S. illnesses are being reported, and on
patients’ families and their surrounding communities.
The Obama Administration has requested $1.5 billion in emergency supplemental appropriations
to address the threat, and congressional committees in both chambers have convened emergency
hearings to assess the situation.
This report provides a brief chronology of events; discusses key actions taken and authorities
invoked by WHO and the U.S. government; provides information about key U.S. government
pandemic flu planning documents; and provides sources for additional information about the
situation as it unfolds. This report will be continually updated to reflect unfolding events.
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April 21
• CDC reports that two children in California recently recovered from apparently
unrelated infections with a unique strain of influenza A/H1N1 containing gene
segments from swine flu viruses. The children had not had contact with pigs,
raising concerns about possible human-to-human transmission, and putting health
authorities on alert.
April 23
• CDC reports five more U.S. “swine flu” cases, three in California and two in
Texas, bringing the total to seven and further increasing concerns about human-
to-human transmission. Most cases experienced mild symptoms and all
recovered. The agency determines that the novel flu strain is susceptible to the
antivirals Tamiflu and Relenza.
April 24
• CDC reports one additional U.S. “swine flu” case in California, bringing the total
to eight, and announces that samples from the deadly outbreak in Mexico match
the novel A/H1N1 strain isolated from patients in the United States, who had
milder illnesses.
• WHO announces that Mexican officials have reported three separate outbreaks of
illness involving hundreds of individuals and including several dozen fatalities.
WHO reports that the virus has primarily struck otherwise healthy young adults
rather than the very young and old, who typically are affected by seasonal flu.

2 Compiled from websites of the World Health Organization (WHO), http://www.who.int/csr/disease/swineflu/en/
index.html; Centers for Disease Control and Prevention (CDC), http://www.cdc.gov/swineflu/; and Center for
Infectious Disease Research and Policy (CIDRAP),
http://www.cidrap.umn.edu/cidrap/content/influenza/swineflu/index.html.
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April 26
• Federal officials declare a public health emergency in response to the outbreak,
as CDC announces nine more cases, bringing the U.S. total to 20 cases in five
states (California, Kansas, New York, Ohio, and Texas). The Secretary of
Homeland Security, Janet Napolitano, announces the release of 25% of the 50
million treatment courses of Tamiflu and Relenza in the Strategic National
Stockpile, along with personal protective equipment and other medical supplies.
CDC also releases guidance on facemask and respirator use and
recommendations for clinicians and public health officials managing flu
outbreaks.
April 27
• CDC confirms 20 more “swine flu” cases, all connected to previous cases at a
New York City high school, bringing the U.S. total to 40 cases. Federal officials
recommend that people avoid non-essential travel to Mexico. FDA issues
Emergency Use Authorizations permitting certain unapproved uses of Tamiflu
and Relenza (such as in very young children), as well as the use of an
unapproved molecular diagnostic test for the new flu strain.
• WHO raises its pandemic alert level from Phase 3 to Phase 4, having concluded
that the novel flu strain is sufficiently transmissible from person to person to
sustain community-level outbreaks. European Union officials warn against non-
essential travel to areas where outbreaks have been detected.
April 28
• CDC reports a total of 64 confirmed U.S. cases of “swine flu” in five states (New
York, California, Texas, Kansas, and Ohio), saying that it is becoming
increasingly clear that the virus is spreading beyond people who recently traveled
to Mexico where the outbreak appears to have originated.
• The Obama Administration asks Congress for a $1.5 billion supplemental
appropriation to combat the outbreak.
• In addition to the U.S. cases, WHO reports a total of 41 confirmed cases in the
following six countries: Mexico (26, including seven deaths), Canada (6), New
Zealand (3), United Kingdom (2), Israel (2), and Spain (2).
April 29
• CDC reports a total of 91 confirmed U.S. cases in 10 states (New York, Arizona,
California, Indiana, Kansas, Massachusetts, Michigan, Nevada, Ohio, and Texas),
including 51 cases in New York City, and confirms the first U.S. “swine flu”
death, in a young child in Texas.
• WHO raises its pandemic alert level from Phase 4 to Phase 5 (evidence of
sustained community-level outbreaks in multiple countries) and, in addition to
the U.S. cases, reports a total of 57 confirmed cases in the following eight
countries: Mexico (26, including seven deaths), Austria (1), Canada (13),
Germany (3), Israel (2), New Zealand (3), Spain (4), and the United Kingdom
(5).
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The World Health Organization (WHO) is the coordinating authority for health within the United
Nations system. It is responsible for providing leadership, guiding a research agenda, setting
norms and standards, articulating evidence-based policy options, providing technical support to
countries, and monitoring and assessing health trends. WHO, in consultation with member
countries and appropriate experts, monitors the global movement of flu strains among humans,
and determines the risk of a global pandemic according to phases, from 1 to 6. Phase 6 is a global
pandemic, in which worldwide or nearly worldwide person-to-person transmission of a novel
influenza virus strain is occurring. Table 1 describes the phases of a flu pandemic, as defined by
WHO.
The current pandemic alert level is Phase 5. It was recently raised from Phase 3 (where it had
been for several years because of the threat of H5N1 avian flu) to Phase 4 on April 27, and then to
Phase 5 on April 29, as the 2009 H1N1 “swine flu” was reported in countries on several
continents.3 WHO pandemic phases are depicted in graphical form in Figure 1, which shows that
WHO considers Phase 5 as a global call for full-strength pandemic response efforts, to continue
throughout a declared Phase 6, were a pandemic to ensue.
Governments have been urged by WHO to develop pandemic influenza preparedness and
response plans. Generally these plans are staged according to WHO pandemic phases. Similarly,
corporations and other interests have also developed comprehensive plans that would unfold
according to WHO phase determinations.
In announcing her decision to raise the level of influenza pandemic alert from Phase 4 to Phase 5
on April 29, WHO Director-General Dr. Margaret Chan said:
All countries should immediately activate their pandemic preparedness plans. Countries
should remain on high alert for unusual outbreaks of influenza-like illness and severe
pneumonia. At this stage, effective and essential measures include heightened surveillance,
early detection and treatment of cases, and infection control in all health facilities. This
change to a higher phase of alert is a signal to governments, to ministries of health and other
ministries, to the pharmaceutical industry and the business community that certain actions
should now be undertaken with increased urgency, and at an accelerated pace.4

3 WHO, “Current WHO Phase of Pandemic Alert,”
http://www.who.int/csr/disease/avian_influenza/phase/en/index.html.
4 WHO, statement by WHO Director-General Dr. Margaret Chan regarding swine influenza, April 29, 2009,
http://www.who.int/mediacentre/news/statements/2009/h1n1_20090429/en/index.html.
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Table 1. WHO Influenza Pandemic Phases
(Current alert level is highlighted)
Phase Description
Phase 1
No animal influenza virus circulating among animals has been reported to cause infection in
humans.
Phase 2
An animal influenza virus circulating in domesticated or wild animals is known to have caused
infection in humans and is therefore considered a specific potential pandemic threat.
Phase 3
An animal or human-animal influenza reassortanta virus has caused sporadic cases of small clusters
of disease in people, but has not resulted in human-to-human transmission sufficient to sustain
community-level outbreaks.
Phase 4
Human-to-human transmission of an animal or human-animal influenza reassortanta virus able to
sustain community-level outbreaks has been verified.
Phase 5
The same identified virus has caused sustained community-level outbreaks in two or more
countries in one WHO region.b
Phase 6
In addition to the criteria defined in Phase 5, the same virus has caused sustained community-level
outbreaks in at least one other country in another WHO region.b
Post-peak
Levels of pandemic influenza in most countries with adequate surveillance have dropped below
Period
peak levels.
Possible New
Level of pandemic influenza activity in most countries with adequate surveillance rising again.
Wave
Post-pandemic
Levels of influenza activity have returned to the levels seen for seasonal influenza in most
Period
countries with adequate surveillance.
Source: Adapted from WHO, Pandemic Influenza Preparedness and Response: A WHO Guidance Document, April
2009, Table 1, p. 13, http://www.who.int/csr/disease/influenza/pipguidance2009/en/index.html.
a. A reassortant virus results from a genetic reassortment process in which genes from animal and human
influenza viruses mix together to create a new strain.
b. WHO governs through six regional offices that do not strictly correspond with the world’s continents. The
WHO regions are the African Region; the Region of the Americas; the South-East Asia Region; the
European Region; the Eastern Mediterranean Region; and the Western Pacific Region. See “WHO–Its
People and Offices,” http://www.who.int/about/structure/en/index.html.

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Figure 1. WHO Influenza Pandemic Phases

Source: WHO, Pandemic Influenza Preparedness and Response: A WHO Guidance Document, April 2009, Figure 3,
p. 31, http://www.who.int/csr/disease/influenza/pipguidance2009/en/index.html.
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In 2005, the World Health Assembly adopted a revision of the International Health Regulations
(IHR), giving a new mandate to WHO and member states to increase their respective roles and
responsibilities for the protection of international public health. The IHR(2005) require signatory
nations (which include the United States) to notify WHO of all events that may constitute a
“Public Health Emergency of International Concern,” and to provide information regarding such
events. The IHR(2005) also include provisions regarding designated national points of contact,
definitions of core public health capacities, disease control measures such as quarantine and
border controls, and others. The IHR(2005) require WHO to recommend, and signatories to use,
control measures that are no more restrictive than necessary to achieve the desired level of health
protection.5
On April 25, 2009, upon the advice of the Emergency Committee called under the rules of the
IHR(2005), the WHO Director-General declared the global threat of H1N1 “swine flu” a Public
Health Emergency of International Concern. This designation calls upon signatories to provide
timely and transparent notification of events to WHO, to collaborate with other countries in
disease reporting and control, and to adopt effective risk communication strategies to reduce the
potential for international disease spread and the likelihood of unilateral imposition of trade or
travel restrictions by other countries.6

5 For more information, see CRS Report RL34144, Extensively Drug-Resistant Tuberculosis (XDR-TB): Emerging
Public Health Threats and Quarantine and Isolation, by Kathleen S. Swendiman and Nancy Lee Jones.
6 WHO, International Health Regulations, http://www.who.int/ihr/en/.
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A number of governments have instituted enhanced passenger screening practices at their borders,
and policymakers have debated more extensive prohibitions against the entry of travelers from
countries or areas affected by the outbreak. The WHO has consistently advised against
compulsory movement restrictions as a means to control influenza, citing a lack of evidence of
their effectiveness, coupled with their potentially harmful effects on public confidence and on
trade. WHO has provided the following message in its daily situation updates since April 27:
WHO advises no restriction of regular travel or closure of borders. It is considered prudent
for people who are ill to delay international travel and for people developing symptoms
following international travel to seek medical attention, in line with guidance from national
authorities.7
WHO has also commented on food safety concerns raised by the outbreak, saying:
There is also no risk of infection from this virus from consumption of well-cooked pork and
pork products. Individuals are advised to wash hands thoroughly with soap and water on a
regular basis and should seek medical attention if they develop any symptoms of influenza-
like illness.8
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On April 27, the Secretary of Homeland Security, Janet Napolitano, stated in a press briefing that
she was serving as the coordinator of the federal response to the flu outbreak, having assumed the
role of Principal Federal Official (PFO).9 According to the National Response Framework (NRF),
which guides a coordinated federal response to disasters and emergencies in general, the
Secretary of Homeland Security leads federal incident response.10
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On April 26, Charles E. Johnson, then the Acting HHS Secretary, who is responsible for
coordinating the public health and medical response to the “swine flu” outbreak, declared a public
health emergency pursuant to Section 319 of the Public Health Service Act.11 Among other
things, this authority enables FDA to implement an authority in the Federal Food, Drug, and

7 WHO, “Situation updates–Swine flu,” http://www.who.int/csr/disease/swineflu/updates/en/index.html.
8 Ibid.
9 Department of Homeland Security, Remarks by Secretary Napolitano at Media Briefing on H1N1 Flu Outbreak,
April 27, 2009, http://www.dhs.gov/ynews/.
10 CRS Report RL34758, The National Response Framework: Overview and Possible Issues for Congress, by Bruce R.
Lindsay. The PFO position has been controversial, however, because it may conflict with the role of the Federal
Coordinating Officer (FCO), a leadership position established in the Robert T. Stafford Disaster Relief and Emergency
Assistance Act (the Stafford Act).
11 HHS, “HHS Declares Public Health Emergency for Swine Flu,” press release, April 26, 2009, http://www.hhs.gov/
news. More information about this authority is available in CRS Report RL33579, The Public Health and Medical
Response to Disasters: Federal Authority and Funding, by Sarah A. Lister.
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Cosmetic Act—the so-called Emergency Use Authorization (discussed below)—allowing for the
use of unapproved medical treatments and tests, under specified conditions, if needed during an
incident.
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If an emerging public health threat is identified for which no licensed or approved product exists,
the Federal Food, Drug and Cosmetic Act authorizes the FDA Commissioner to issue an
Emergency Use Authorization (EUA) so that unapproved but potentially helpful countermeasures
can be used to protect the public health.12 On April 27, pursuant to authority provided by the prior
public health emergency determination, FDA issued EUAs to allow emergency use of (1)
oseltamivir (Tamiflu) and zanamivir (Relenza) for the treatment and prophylaxis of influenza; (2)
disposable respirators for use by the general public; and (3) an unapproved diagnostic test for the
new flu strain.13
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On April 27, CDC issued a Travel Health Warning, its highest advisory level, recommending that
U.S. travelers avoid all nonessential travel to Mexico.14 (The agency had issued a Travel Health
Precaution, the next lower advisory level, on April 25.) On April 28, the Department of State
issued a travel alert to U.S. citizens of the health risks of travel to Mexico due to the “swine flu”
situation, noting the CDC’s Travel Health Warning of the previous day.15
The advisories above, regarding travelers leaving the United States, are voluntary. With respect to
incoming travelers, Customs and Border Protection (CBP), in DHS, is monitoring them at ports
of entry (typically a visual inspection or interview regarding possible symptoms), providing
information about disease control measures, and referring symptomatic persons to a CDC
quarantine station or a local public health official for evaluation. According to CBP, “at this time
all U.S. ports of entry are open and operating as normal with officers using risk based border
screening.”16 WHO and CDC officials have commented that scientific evidence does not support
closure of a border to travelers as an effective means of controlling the spread of influenza.17
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On April 27, Representative Obey, the Chairman of the House Appropriations Committee, and
Senator Harkin, the Chairman of the Senate Labor, Health and Human Services, Education, and

12 Food and Drug Administration, Guidance: Emergency Use Authorization of Medical Products, July 2007,
http://www.fda.gov/oc/guidance/emergencyuse.html.
13 Information is available at CDC, “Swine Flu: Emergency Use Authorization (EUA) of Medical Products and
Devices,” http://www.cdc.gov/swineflu/eua/.
14 CDC, Travel Health Warning: Travel Warning: Swine Influenza and Severe Cases of Respiratory Illness in Mexico–
Avoid Nonessential Travel to Mexico, April 27, 2009, http://wwwn.cdc.gov/travel/contentSwineFluMexico.aspx.
15 U.S. Department of State, Bureau of Consular Affairs, Travel Alert: Mexico - 2009-H1N1 Influenza, April 28, 2009,
http://travel.state.gov/travel/cis_pa_tw/pa/pa_3028.html.
16 U.S. Customs and Border Protection, CBP Monitors H1N1 Flu Outbreak; All Ports Operating Routinely, April 30,
2009, http://www.cbp.gov/xp/cgov/newsroom/alerts/flu/.
17 Donald G. McNeil, “Containing Flu Is Not Feasible, Specialists Say,” The New York Times, April 29, 2009.
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Related Agencies Appropriations Subcommittee, both suggested that Congress might add funds to
the pending defense supplemental appropriations request to respond to the recent swine flu
outbreak.18 On April 28, the White House sent a letter to congressional leaders requesting $1.5
billion for swine flu preparedness measures, including supplementing stockpiles of antiviral
medications; developing a vaccine; supporting monitoring, diagnostic, and public health response
capabilities; and assisting international efforts to control the disease.19
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When news of the outbreak of a new flu strain emerged, WHO, CDC, and others referred to the
virus as H1N1 “swine influenza” or “swine-origin influenza.” This is based on the presumed
evolutionary origin of the strain from strains that circulate in swine, since it contains genetic
material typically found in North American and Eurasian swine flu strains. However, there has
been no evidence to date that pigs are involved in the transmission of the virus involved in the
current outbreak. The designation of the outbreak as “swine flu” has concerned the swine
industry, who believe it has led to unwarranted economic and trade consequences for swine and
pork products. Others have raised concerns that because of religious practices that call for the
avoidance of swine and pork products by some persons of Jewish or Muslim faiths, disease
control measures may be compromised in these groups if illness is perceived as a social stigma.
On April 29, 2009, officials from HHS, DHS, and other federal agencies referred to the virus as
“2009 H1N1.”20 On April 30, 2009, WHO began referring to the new strain as influenza A(H
1N1).
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Numerous federal and other planning documents that are specific for the response to a flu
pandemic have been published. Selected documents are listed below. These plans are intended to
address a pandemic caused by any applicable flu strain, but they were written when there was
significant global concern about H5N1 avian flu. Unless otherwise noted, these plans can be
found on a government-wide pandemic flu website managed by HHS.21
• The National Strategy for Pandemic Influenza, November 2005, published by the
Homeland Security Council, outlines general responsibilities of individuals,
industry, state and local governments, and the federal government in preparing
for and responding to a pandemic.
• National Strategy for Pandemic Influenza, Implementation Plan, May 2006,
published by the Homeland Security Council, assigns more than 300
preparedness and response tasks to departments and agencies across the federal

18 Rob Margetta, “Harkin, Obey Want Swine Flu Funds in Supplemental,” CQ Today, April 27, 2009.
19 Drew Armstrong, “Obama Seeks $1.5 Billion in Supplemental To Fight Flu Outbreak,” CQ Today, April 28, 2009.
For more information, see CRS Report R40531, FY2009 Spring Supplemental Appropriations for Overseas
Contingency Operations, coordinated by Stephen Daggett and Susan B. Epstein.
20 See, for example, HHS, “Secretary of Health and Human Services Kathleen Sebelius Holds News Conference on
Swine Flu,” transcript, comments of Anthony Fauci, Director of the National Institute of Allergy and Infectious
Diseases, National Institutes of Health, April 29, 2009.
21 See http://www.pandemicflu.gov/plan/federal/index.html.
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government; includes measures of progress and timelines for implementation;
provides initial guidance for state, local, and tribal entities, businesses, schools
and universities, communities, and non-governmental organizations on the
development of institutional plans; provides initial preparedness guidance for
individuals and families. One- and two-year implementation status reports have
also been published.
• The HHS Pandemic Influenza Plan, November 2005, provides guidance to
national, state and local policy makers and health departments, outlining key
roles and responsibilities during a pandemic and specifying preparedness needs
and opportunities. This plan emphasizes specific preparedness efforts in the
public health and health care sectors.
• The HHS Pandemic Influenza Implementation Plan, Part I, November 2006,
discusses department-wide activities: disease surveillance; public health
interventions; medical response; vaccines, antiviral drugs, diagnostic tests, and
personal protective equipment (PPE); communications; and state and local
preparedness.
• Department of Defense Implementation Plan for Pandemic Influenza, August
2006, provides policy and guidance for the following priorities: (1) force health
protection and readiness; (2) the continuity of essential functions and services;
(3) Defense support to civil authorities (i.e., federal, state, and local
governments); (4) effective communications; and (5) support to international
partners.
• VA Pandemic Influenza Plan, March 2006, provides policy and instructions for
Department of Veterans Affairs (VA) in protecting its staff and the veterans it
serves, maintaining operations, cooperating with other organizations, and
communicating with stakeholders.
• Pandemic Influenza Preparedness, Response, and Recovery Guide for Critical
Infrastructure and Key Resources, published by DHS, September 2006, provides
business planners with guidance to assure continuity during a pandemic for
facilities comprising critical infrastructure sectors (e.g., energy and
telecommunications) and key resources (e.g., dams and nuclear power plants).
• State pandemic plans: All states were required to develop and submit specific
plans for pandemic flu preparedness, as a requirement of grants provided by
HHS.22

22 For more information, see HHS, Assessment of States’ Operating Plans to Combat Pandemic Influenza: Report to
Homeland Security Council, January 2009, at http://www.pandemicflu.gov/plan/states/index.html, and CRS Report
RL34190, Pandemic Influenza: An Analysis of State Preparedness and Response Plans, by Sarah A. Lister and Holly
Stockdale.
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CRS Reports on Public Health and Emergency Preparedness http://apps.crs.gov/cli/
cli.aspx?PRDS_CLI_ITEM_ID=3276&from=3&fromId=13
World Health Organization
• Information about the current H1N1 swine flu situation: http://www.who.int/csr/
disease/swineflu/en/index.html
• Pandemic Influenza Preparedness and Response: A WHO Guidance Document,
(April 2009): http://www.who.int/csr/disease/influenza/pipguidance2009/en/
index.html
• Current phase of flu pandemic alert: http://www.who.int/csr/disease/
avian_influenza/phase/en/index.html
• International Health Regulations (2005): http://www.who.int/topics/
international_health_regulations/en/
U.S. Government
• CDC 2009 H1N1 flu page: http://www.cdc.gov/swineflu/investigation.htm
• Pandemic flu planning information: http://www.pandemicflu.gov/ (Note: much of
this information is in the context of planning for the H5N1 avian flu threat.)
• Department of Health and Human Services Pandemic Planning Updates,
addressing monitoring and surveillance, vaccines, antiviral medications, state and
local preparedness, and communications, through January 2009:
http://www.pandemicflu.gov/plan/federal/index.html#hhs (Note: much of this
information is in the context of planning for the H5N1 avian flu threat.)

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Sarah A. Lister
C. Stephen Redhead
Specialist in Public Health and Epidemiology
Specialist in Health Policy
slister@crs.loc.gov, 7-7320
credhead@crs.loc.gov, 7-2261

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