H1N1 after action review: learning from the unexpected, the success and the fear

In less than 3 months, a novel influenza virus – influenza A (H1N1) – emerged in North America and appeared rapidly around the world, eventually becoming the first declared influenza pandemic in 40 years. Although the H1N1 pandemic had not ended at the time of writing, enough experience with this virus and the responses to it have accrued to permit assessment of its impact and implications. Despite this novel virus‘ lack of lethal virulence, its emergence and spread constitute extraordinary global health events that will affect how future threats will be approached. This influenza pandemic has generated scientific surprises and policy controversies, tested plans and preparations made in expectation of such global health events, and raised concerns and fears about what might be over the horizon concerning influenza and other emerging infectious diseases.

Viral surprise

As of 26 June 2009, the WHO reported that over 100 WHO member states had cumulatively reported 58,914 cases and 263 deaths involving the novel H1N1 virus [101]. These statistics provide important information but do not capture the scientific surprise and policy controversies that have accompanied this outbreak. Certainly, given the mutational wickedness of influenza, public-health officials have expected new influenza viruses to appear and threaten national and global health. Still, the novel H1N1 virus that emerged appeared to catch scientific, public health and policy experts by surprise.

Most concerns about a future influenza crisis arose from worries that the avian influenza A (H5N1) virus would mutate into a pathogen combining high virulence and ready human–human transmissibility. The most likely ‘hot spot‘ for the development of such a threatening virus was thought to be Asia, where the H5N1 virus has become dangerously endemic. The appearance of a novel H1N1 influenza virus in Mexico and the USA did not meet the H5N1-centric expectations that had developed since H5N1‘s emergence in 2004.

In addition, the genetic makeup of the novel H1N1 virus contained more evidence of swine origin than avian origin. However, the virus was infecting and being transmitted between humans, not pigs, making it not a swine virus, despite the nearly universal initial reference to it as ‘swine influenza‘ (much to the commercial chagrin of the pork industry). Although pigs have long been identified as a locale for the mixing of swine, avian and human influenza viruses, H1N1‘s genetic complexity has stymied efforts to trace the origins of this genetic reassortment, leaving many scientific questions unanswered and creating new policy challenges.

Another unexpected feature of this virus‘ emergence was its moderate impact in terms of morbidity and mortality. With the virulence of H5N1 infections in humans in mind, combined with the constantly conjured nightmare of the great 1918–1919 influenza pandemic, the prevailing assumption was that the next pandemic would be not only global in its geographic spread, but also severe in terms of illnesses and deaths. Although the H1N1 virus does not replicate patterns seen with seasonal influenza, the virus has not, to date, proved to be the indiscriminate killer that was feared.

Pandemic that was, & was not, a pandemic

These scientific surprises contributed to a major policy controversy that emerged from H1N1‘s appearance and spread – the application of the WHO‘s pandemic-alert system to the outbreak. Adopted as part of preparations for pandemic influenza in the wake of the H5N1 scare, the alert system‘s various phases correspond with recommended actions that countries should take. As the H1N1 virus‘ moderate impact became clear, the WHO‘s pandemic-alert system came under criticism for failing to include virus severity as a criterion along with geographical spread, a shortcoming the WHO agreed to address in revising the alert system.

The WHO found itself in the epidemiologically and politically awkward position of facing a pandemic (according to its definition) that should not, according to many governments and experts prior to and during the World Health Assembly meeting in May 2009, be declared a Phase 6 pandemic. Only with political difficulty and intense diplomacy did the WHO maneuver itself into a position to raise the pandemic alert level to Phase 6 and declare a pandemic on 11 June 2009. This unanticipated, less-than-optimal application of the pandemic-alert system raised questions over whether politics had unduly influenced public health and scientific decision-making, or if poor public-health decisions reflected in the pandemic-alert system necessitated political interventions.

The unprecedented obscured, confused & infringed

Another interesting, and unexpected, feature of the H1N1 episode involved how the controversy over the pandemic-alert system overshadowed the first utilization of provisions in the WHO‘s International Health Regulations 2005 (IHR 2005). Adopted in 2005, and legally binding since June 2007, the IHR 2005 radically revised the international law on infectious disease control [1]. The H1N1 outbreak triggered the first time under the IHR 2005 that the WHO Director General declared a “public-health emergency of international concern” and issued temporary recommendations to guide country responses to such an emergency [2].

The IHR 2005 also played a critical role in the surveillance undertaken for H1N1 cases because countries are obliged to report all cases of human influenza caused by new viral subtypes to the WHO. Unlike China‘s failed attempt to hide SARS cases, the H1N1 outbreak has not yet witnessed countries engaging in covering up H1N1 cases. The influenza-preparedness planning governments have been undertaking has also supported the effective operation of the IHR 2005 in this outbreak.

However, the successful application of the IHR 2005 to the H1N1 outbreak tended to be obscured by, and confused with, the use of the pandemic alert system, even though the IHR 2005 contain no provisions that mention or authorize anything about that system. Part of the confusion stemmed from the use of the Emergency Committee established under the IHR 2005 to advise the WHO Director General on whether to raise the phase levels under the pandemic alert system. Contrary to the WHO Director General‘s assertions that the Emergency Committee was established for providing advice on this system [102], the Committee‘s mandate under the IHR 2005 does not authorize it to provide such advice to the Director General, which raises policy and legal questions about how the authorities in the IHR 2005 and the procedures of the pandemic-alert system relate to each other.

Problems under the IHR 2005 also arose because certain countries applied unjustified measures to the trade and travelers of H1N1-affected nations. Contrary to scientific evidence and principles, and rules under the IHR 2005 and international trade agreements, some countries banned pork exports from countries experiencing H1N1 cases. Human rights concerns were also raised about the manner in which, for example, China applied quarantine measures to Mexican and Canadian nationals arriving from or already present in China. These measures prompted the WHO, under the IHR 2005, to request that China provide the public health justification for its actions. Although unfortunate, such excessive measures against trade and travel in response to the H1N1 threat were not widespread, meaning that the world experienced fairly robust compliance with the relevant trade and human rights rules in the IHR 2005.

Future perspective

Tempering the positive aspects of national and global responses to the H1N1 virus is the realization that whilst it did not trigger the crisis everyone feared, it has exposed serious problems. The crisis revealed weaknesses in surveillance and response capabilities of many countries, especially developing and least-developed nations. It drew attention to the challenges that implementation of the IHR 2005‘s obligations on developing and maintaining core surveillance and response capacities create – challenges that remain unmet by a global strategy and adequate funding. The outbreak exposed continuing fissures and frictions between human and animal health communities, which impedes improved collaborations on zoonotic diseases. Strategies for developing and distributing vaccines and antivirals for H1N1 recalled the unresolved disputes about access to technological benefits of scientific research on influenza virus strains raised by Indonesia and other developing countries in the context of the H5N1 virus. Finally, the emergence of H1N1 in the midst of a global economic crisis demonstrated the vulnerability of progress made on pandemic influenza preparedness and the IHR 2005 to larger macroeconomic forces.

The H1N1 virus that captured the world‘s attention in April and May 2009, but then faded from the limelight, might retain its current epidemiological profile or, as public-health experts fear, it might mutate or genetically mix with other influenza viruses to produce a more dangerous threat in the autumn 2009 influenza season. The H1N1 outbreak has demonstrated that geographical containment of a readily transmissible influenza virus is impossible, which places additional policy weight on improving surveillance and response capacities, as outlined in the IHR 2005 and pandemic influenza-preparedness strategies. With many global political, economic and ecological challenges presently pressuring policymakers, there is a great danger that insufficient political, economic and intellectual capital will be focused on learning the lessons of the H1N1 outbreak and implementing strategies to prepare for what certainties and surprises pathogens and politics will generate in the future.

Financial & competing interests disclosure

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.