The 1918 influenza pandemic: Lessons for 2009 and the future

Abstract

The 1918 to 1919 H1N1 influenza pandemic is among the most deadly events in recorded human history, having killed an estimated 50 to 100 million persons. Recent H5N1 avian influenza epizootics associated with sporadic human fatalities have heightened concern that a new influenza pandemic, one at least as lethal as that of 1918, could be developing. In early 2009, a novel pandemic H1N1 influenza virus appeared, but it has not exhibited unusually high pathogenicity. Nevertheless, because this virus spreads globally, some scientists predict that mutations will increase its lethality. Therefore, to accurately predict, plan, and respond to current and future influenza pandemics, we must first better-understand the events and experiences of 1918. Although the entire genome of the 1918 influenza virus has been sequenced, many questions about the pandemic it caused remain unanswered. In this review, we discuss the origin of the 1918 pandemic influenza virus, the pandemic’s unusual epidemiologic features and the causes and demographic patterns of fatality, and how this information should impact our response to the current 2009 H1N1 pandemic and future pandemics. After 92 yrs of research, fundamental questions about influenza pandemics remain unanswered. Thus, we must remain vigilant and use the knowledge we have gained from 1918 and other influenza pandemics to direct targeted research and pandemic influenza preparedness planning, emphasizing prevention, containment, and treatment.

N-Linked Glycosylation of the Hemagglutinin Protein Influences Virulence and Antigenicity of the 1918 Pandemic and Seasonal H1N1 Influenza A Viruses

“…Following the 1918 pandemic, the H1N1 influenza virus continued to circulate in humans, causing annual epidemics with the exception of years 1957 to 1977, in which the H2N2 and H3N2 viruses emerged in humans to become the dominant subtypes (3). Unlike seasonal influenza, in which infection usually causes only mild respiratory symptoms in most healthy adults, the 1918 virus caused severe respiratory illness with high mortality rates (4,5). In particular, mortality rates were high among healthy adults 15 to 34 years old, an age group not usually associated with severe illness or death from influenza (5).…”

“…Unlike seasonal influenza, in which infection usually causes only mild respiratory symptoms in most healthy adults, the 1918 virus caused severe respiratory illness with high mortality rates (4,5). In particular, mortality rates were high among healthy adults 15 to 34 years old, an age group not usually associated with severe illness or death from influenza (5). In 2009, a novel influenza A H1N1 virus [A(H1N1)pdm09] emerged in humans and spread throughout the world, resulting in the declaration of a pandemic by the World Health Organization (WHO) (6).…”

Das pandemische H1N1-Influenzavirus/2009

“…Auch das gegenwärtige pandemische Influenzavirus (H1N1) 2009 scheint hier keine Ausnahme zu sein[2,4]. Der direkte Über-gang eines IAV aus dem aviären Bereich auf den Menschen mit der direkten Folge einer Pandemie konnte bislang nicht sicher belegt werden[29,30]. Eine engmaschigere und gezieltere weltweite Surveillance porziner, aber auch aviärer IAV-Infektionen könnte das Auffinden solcher Vorläuferviren begüns-tigen, bevor sie sich zu einem Pandemievirus weiterentwickeln.…”

Influenza in the 21st century: a call for papers

“…Influenza pandemics can have an even bigger impact in the wider population, including younger age groups, because of a lack of population immunity to the new strain. 3,4 Influenza is, however, both a vaccine-preventable and treatable disease. Opportunities remain for the improvement of both vaccines and treatments, and for ensuring wider equitable and affordable access to these interventions, so that the morbidity and mortality from seasonal, zoonotic and pandemic influenza can be reduced.…”