Challenges of the 2009 H1N1 Pandemic Influenza:

Charles Penn

Global Influenza Programme

World Health Organization

Geneva

Challenges of 2009 H1N1 Pandemic | March 16th 20102 |

Influenza Pandemics 20th CenturyInfluenza Pandemics 20th Century

A(H1N1) A(H2N2) A(H3N2)

1918: “Spanish Flu” 1957: “Asian Flu” 1968: “Hong Kong Flu”

20-40 million deaths 1-4 million deaths 1-4 million deaths

Credit: US National Museum of Health and Medicine

Challenges of 2009 H1N1 Pandemic | March 16th 20104 |

Definition of "pandemic"Definition of "pandemic"

Many definitions:– "Epidemic over a wide geographic area and affecting a large

proportion of the population"– "Worldwide epidemic"

Context of influenza virus:– New strain – Antigenic "shift" (new subtype)– Transmissible human to human– Cause illness

Challenges of 2009 H1N1 Pandemic | March 16th 20105 |

OutlineOutline

History of the pandemic

Current status (epidemiology)

Clinical presentation and impact

Vaccines & antivirals

Challenges of 2009 H1N1 Pandemic | March 16th 20106 |

4 April: outbreak of ILI in Veracruz

15-17 April: clusters of severe pneumonia in Mexico

April May June July August OctoberSeptemberMarch

Pandemic H1N1 2009 TimelinePandemic H1N1 2009 Timeline

Challenges of 2009 H1N1 Pandemic | March 16th 20107 |

Age-related distribution of deaths from severe pneumonia compared to influenza seasons 2006-08

(Mexico, 24 March- 29 April 2009)

Age-related distribution of deaths from severe pneumonia compared to influenza seasons 2006-08

(Mexico, 24 March- 29 April 2009)

During 5-weeks period, 2155 cases of severe pneumonia with 821 hospitalizations + 100 deaths: 87% of deaths and 71% of severe pneumonia cases aged 5- 59 yrs

Challenges of 2009 H1N1 Pandemic | March 16th 20108 |

4 April: outbreak of ILI in Veracruz

15-17 April: clusters of severe pneumonia in Mexico

27 April: WHO phase 4

May June July August OctoberSeptemberMarch

21 April: 2 cases of H1N1 confirmed in California, USA

23 April: H1N1 confirmed in several patients in MX

27 April: Canada and Spain report H1N1 cases

April

Pandemic H1N1 2009 TimelinePandemic H1N1 2009 Timeline

29 April: WHO phase 5

Challenges of 2009 H1N1 Pandemic | March 16th 20109 |

4 April: outbreak of ILI in Veracruz 29 April: WHO phase 5

April

27 April: WHO phase 4

11 June: WHO phase 6 pandemic declared; H1N1 in 74 countries

May June July August OctoberSeptemberMarch

21 April: 2 cases of H1N1 confirmed in California, USA

Pandemic H1N1 2009 TimelinePandemic H1N1 2009 Timeline

Challenges of 2009 H1N1 Pandemic | March 16th 201010 |

29 April: WHO phase 5

April

27 April: WHO phase 4

11 June: WHO phase 6 pandemic declared; H1N1 in 74 countries

May June July AugustMarch

WK 24: SA H3N2 peak

Increasing activity throughout Northern Hemisphere

September October

Pandemic H1N1 2009 TimelinePandemic H1N1 2009 Timeline

Challenges of 2009 H1N1 Pandemic | March 16th 201011 |

Challenges of 2009 H1N1 Pandemic | March 16th 201012 |

Challenges of 2009 H1N1 Pandemic | March 16th 201013 |

Exacerbation of Underlying conditions

Disease presentation and progressionDisease presentation and progression

Uncomplicated self limiting illness

Severe lower respiratoryTract infection:

Viral pneumonitisARDS

Bacterial pneumonia

Challenges of 2009 H1N1 Pandemic | March 16th 201014 |

Age-Specific (population based) hospitalization rates (Australia, Chile, Argentina, New Zealand)

Age-Specific (population based) hospitalization rates (Australia, Chile, Argentina, New Zealand)

Challenges of 2009 H1N1 Pandemic | March 16th 201015 |

Within Vaccine Area, Four Particular Priorities

Within Vaccine Area, Four Particular Priorities

Facilitate rapid development and manufacture of pandemic vaccine

Provide guidance on use of pandemic vaccine

Monitor vaccine safety

Open or increase vaccine access for developing & middle income countries

Challenges of 2009 H1N1 Pandemic | March 16th 201016 |

Update on DonationsUpdate on Donations

13 donor governments*

5 donor manufacturers**

190 M vaccine doses pledged

74.5 M syringes pledged

US$ 46M pledged for operations

**Becton-Dickinson, CSL, GSK, MedIummune, Sanofi Pasteur, Temptime

*Australia, Belgium, Brazil, Canada, France, Germany, Italy, Japan, New Zealand, Singapore, Switzerland, Thailand, UK, USA (and the Bill and Melinda Gates Foundation)

Challenges of 2009 H1N1 Pandemic | March 16th 201017 |

Guidelinesfor use

Equitable Access

Monitoringeffectiveness

Role of AntiviralsRole of Antivirals

Challenges of 2009 H1N1 Pandemic | March 16th 201018 |

Final commentsFinal comments

Never enough information

World looks to WHO for leadership– Evidence-based responses

– Be prepared to go where others don't

– Unintended consequences

Tide of media interest, public opinion

Better prepared than ever before BUT...– Virus still spread faster than we could act

– News and opinion travels faster and further than ever before

Challenges of 2009 H1N1 Pandemic | March 16th 201019 |

Some successesSome successes

Rapid isolation and characterisation of new virus

Vaccine developed and available in 6 months

New antivirals since last pandemic which are effective– Reducing severity of illness, hospitalisation, death

Advances in healthcare (especially CC/ICU)

Clinical networks effective in real time– From science to public health to critical care

Challenges of 2009 H1N1 Pandemic | March 16th 201021 |

THANK YOU