Influenza

NexBio is developing Fludase®, a broad-spectrum drug candidate for the prophylaxis and treatment of respiratory infections caused by all variations of influenza and parainfluenza virus, including the viruses that may cause an influenza pandemic. See the Fludase page for more information.

INFLUENZA

Influenza is a contagious respiratory illness that can cause mild to severe illness, and at times lead to death. The influenza viruses are highly infectious respiratory pathogens that have plagued the human race since ancient times. Influenza is characterized by recurrent annual epidemics, and periodic worldwide pandemics.

The two strains of influenza virus that are responsible for annual seasonal epidemics are A and B. The Influenza A viruses are further broken down into sub-types such as H1N1 and H3N2. Over the course of a flu season, typically one or two strains and subtypes circulate and cause illness. All the while and in the background, the influenza viruses are changing through a process called "antigenic drift," preparing to infect people anew for the next year’s season.

The direct and indirect social and economic impacts of influenza are enormous. Every year, influenza is the most common cause of medically-attended acute respiratory illness in the U.S. On average, up to 20% of the population in the United States become infected with an influenza virus annually, resulting in approximately 300,000 hospitalizations and 36,000 deaths. According to the Centers for Disease Control and Prevention (CDC) and the American Lung Association, influenza causes 70 million lost workdays and 38 million lost school days per year (Adams, P.F, 1996. National Center for Health Statistics. Vital Health Sta. 10:200). Remarkably, at peak season, as many as 7.5% of every doctor visit in the U.S. (for any reason) is due to a patient presenting with “flu-like symptoms.”

Certain people, such as the elderly, young children, and people with certain chronic health conditions (e.g. asthma, COPD and diabetes) are at higher risk for serious complications. The size of this high-risk population, for whom doctors are especially aggressive in prescribing anti-viral medications, is vast, numbering in the tens of millions.

A tool to track the emergence of seasonal outbreaks is Google’s Flu Trends.

To track the ongoing Pandemic Influenza A(H1N1) progression, please go to 2009 H1N1 Flu Outbreak Map.

PANDEMIC INFLUENZA

Fig 1: 2009 H1N1 Flu Outbreak Map

A pandemic is a global disease outbreak. A pandemic occurs when a new influenza virus emerges for which people have little or no immunity, and for which there is no vaccine. The disease spreads easily person-to-person, causes serious illness, and can sweep around the world in very short time.

In the past century there have been three influenza pandemics: 1918, 1957, and 1968. Together, they resulted in at least 50 million deaths. Pandemics typically result from an avian influenza virus acquiring the ability to infect and spread among humans. It has long been thought that the next pandemic would be caused by H5N1 (“Bird Flu”), an especially lethal influenza virus strain. However, unexpectedly, Pandemic Influenza A(H1N1), has emerged as well. Thus far, it has not been nearly as virulent as H5N1; however, given influenza’s ability to mutate, this could change.

In the worst case, based on World Health Organization analysis, up to 25% of the world’s population may be infected in a pandemic within a matter of months, and the death rate may reach 30% or higher (Enserink, M., 2003. Science 300:718). The potential cost of a worldwide influenza pandemic is staggering. In October of 2008, Bloomberg world news reported: “A flu pandemic could kill 71 million people worldwide and push the global economy into a “major global recession'' costing more than $3 trillion, according to raised estimates by the World Bank of a worst-case scenario.” As said by the famous philanthropist, Mary Lasker:

"If you think research is expensive, try disease."

1918 “SPANISH FLU” PANDEMIC

The pandemic influenza of 1918 serves as an historical precedent for pandemic flu outbreak. No one knows exactly how many people died during the 1918-1919 influenza pandemic, but recent estimates have estimated global mortality at anywhere between 30 and 50 million. An estimated 675,000 Americans were among the dead. For a walk through history please see the Pandemic Influenza Storybook, provided by the CDC.

U.S. GOVERNMENT INFLUENZA PANDEMIC PREPARATION

The U.S. Government is allocating substantial resources for global influenza pandemic preparedness. For more information about the U.S. Governments efforts, as well as additional influenza information, see:

National Institute of Allergy and Infectious Diseases (NIAID), NIH, “Flu webpage”

U.S Dept. of Health and Human Services (HHS), “Pandemic Influenza webpage”