Pandemic (H1N1) 2009: The Public Health Response Dr. Sylvie Briand Global Influenza Programme WHO, Geneva

Faces of the Pandemic: Old and New

Pandemic (H1N1) 2009 Overview As if 15 August 2010, 215 countries and territories have reported cases 18,631 laboratory-confirmed deaths in 125 countries Official numbers significantly underestimate actual numbers Widespread community transmission in all areas From April 2009 to August 2010

Pandemic Response Tools Spanish flu pandemic Asian flu pandemic Hong Kong flu pandemic A (H1N1) 2009 pandemic H5N1 Asia 504 C 299 D H5N1 Hong Kong 18 Cases (C) 6 Deaths (D) Sulfonamides (1939) Penicillin (1945) Cephalosporins (1964) Aminoglycosides (1943) Erythromycin (1952) Introduction of other classes of antibiotics Antibiotics Amatadane for influenza (1966) Rimatadane (1993) Neuraminidase inhibitor Oseltamivir and Zanamivir (1999) Antivirals PH measures (i.e. school closures, mask, mass gathering) Non-pharmaceutical Interventions Inactivated Influenza Vaccine (IIV) (1944) Improved IIV (1960 purified) IIV (1968 fragmented) IIV (1980 sub-unit) GISN (1952) Cell-based IIV (2007) LAIV (live-attenuated, 1960, Russia) Adjuvanted IIV (1997) Vaccines LAIV (2003, USA)

Pandemic Response Tools Virus and benefit sharing discussion (2007) PIP OEWG Pandemic Preparedness Guidelines (1999): 3 phases PP guide (2005): 6 phases PP guide (2009): 6 phases Revision of International Health Regulations (IHR) (1969) Plague Yellow fever Cholera IHR revision Includes all Public Health Emergencies of International Concern (PHEIC) (2005) Spanish flu pandemic Asian flu pandemic Hong Kong flu pandemic A(H1N1) 2009 pandemic H5N1 Asia 504 C 299 D H5N1 Hong Kong 18 C 6 D SARS Global >8000 C 774 D

Assessment of Severity Characteristics Source: Weekly Epidemiological Record, 13 November 2009.

Infection and Disease Broad clinical spectrum of disease –High proportion of pauci or asymptomatic –10-50% of GI symptoms –Severe viral pneumonia in healthy adults –10-20% of hospitalizations required ICU Groups at increased risk of severe disease once infected (hospitalization, ICU, death) –Chronic medical conditions –Pregnant women –Very young and the elderly –Obese –Aboriginal/ethnic minorities –40% were previously healthy Highest rates of clinical infection: Teens and young adults Highest rates of hospitalization: Children < 5 (median age 20s-30s) Highest rates of death: Adults (median 35-51; younger age group compared to seasonal influenza)

How is this pandemic different? –First large scale response under the revised International Health Regulations (2005) framework –Global sharing of information and viruses through expert networks E.g. Virus sharing: As of 5 May 2010, 155 countries shared 26,066 specimens with WHO Collaborating Centres –Significant, previous pandemic preparedness efforts, incl. the area of risk communication E.g. 140 countries with pandemic preparedness plans before the pandemic –Access to –antibiotics –antiviral –vaccines (developed and available in 6 months) –high-quality health care (i.e. ICU) –Early detection and response at international level E.g. Virus sequence made publicly available on 25 April 2009 RT-PCR kits available on 2 May 2009

Spread of Pandemics 1957: Spread throughout China in 6 weeks and throughout the world in 6 months : Started in North America; spread to all continents in less than 9 weeks and throughout the world in 10 months – Announcement of pandemic phase 6 on 11 June countries reporting cases of (H1N1) 2009 virus –West Africa reported A (H1N1) pandemic outbreaks only in early 2010

Continued Global Spread of H1N1 April February 2010 April 2009May 2009 (1 month)July 2009 (3 months) September 2009 (5 months) December 2009 (8 months) February 2010 (10 months)

Proposed 2009 Phases Structure and Pandemic Disease "Risk" Sustained human-to-human transmission Time Predominantly animal infections; Limited transmissibility among people Geographic spread Post Peak Post Pandemic Rapid containment

Early Responses to the Pandemic No travel restrictions. Attempt to contain the spread with societal measures (e.g. school closures or antiviral prophylaxis in close communities). More information is needed to assess the impact and cost effectiveness of the various strategies.

Molecular Evolutionary Analysis of the Influenza A (H1N1) pdm, May–September, 2009: Temporal and Spatial Spreading Profile of the Viruses in Japan. (Shiino T et al. PLoS ONE 1 June 2010, Vol. 5:6) School closure: 16 May – 5 June (Kobe prefecture) Source: Infectious Agents Surveillance Report, 2009

Time course of the H1N1 pandemic for select countries* Peak(s)** Sporadic Cases Detected Cases detected Data sources vary by country and include: country- provided epi curves of case onset; ILI consultation rates; Virus isolates by date; percentage of positive specimens collected; media source (first case report for some countries). *Table developed by: Maria Van Kerkove PhD, MRC Centre for Outbreak Analysis and Modeling, Imperial College London ** N.B. Not all countries have detected peak inactivity.

Global Spread of Pandemic (H1N1) 2009, Co-circulation of Viruses

Challenges

Surveillance and Severity Assessment Severity assessed and monitored with a basket of indicators –3 dimensions: Severity of the disease (clinical epidemiological and virological) Vulnerability of the population Capacity to respond During the pandemic, the heterogeneity of systems and indicators has been a major challenge for global monitoring Different age groups No standardized definition of underlying factors No standardized definition of Influenza deaths Different laboratory capacity More than 100 countries have very limited or no influenza surveillance capacity

Phases in Preparedness Guidelines Since 1999, pandemic phases have been used as a tool for planning pandemic responses at global and country levels. Pandemic phases were never used during a pandemic. Main challenge: Publication of new guidelines in early 2009 presented a communications challenge, namely helping the media and Member States (MS) understand the meaning of the phases version

Communications The first phase went well: Early announcement, transparent communication Then things started to unravel: Conspiracy theories started to spread in media and through networks on the internet The consequences were : –Misunderstanding of the public health response from the general public and low uptake of vaccine in some countries –A number of parliamentary enquiries and external reviews of technical agencies' responses to the pandemic New sources of information dissemination have to be taken into account in future pandemic preparedness plans: internet, blogs, virtual social networks

Naming of the Pandemic

Global Health Challenges International mass gatherings (Hajj, FIFA World Cup, Vancouver Olympics) Global solidarity –Access to antivirals Deployment to 72 countries –Access to pandemic vaccines Deployment started in November 2009 As of 30 August 2010, reached 72 countries 73 million doses

Concluding Observations Certain events were correctly anticipated –Eventual emergence of a pandemic –Spread was more rapid than in the past Certain events theoretically acknowledged, but still a surprise –Started in North America –Origin of pandemic virus came from swine H1 viruses Certain events were simply surprising –Effectiveness of one vaccine dose Preparedness was crucial but remains incomplete Impact of control measures on the spread and severity of the disease are being assessed

Acknowledgments Hundreds of people have contributed to the global response to the pandemic (H1N1) 2009 –Global Influenza Programme and WHO regional offices –Technical partners, including national CDC, ECDC, national influenza centres of GISN, WHO CC and academia –Professionals at country level participating in technical networks (Ministries of Health, Public health agencies)

Thank you 谢谢 Merci Gracias