But every 30 or 40 years or so, an especially serious flu season can develop into a worldwide epidemic — known as a pandemic — that can claim millions of lives including young and otherwise healthy people. .

Computer generated model of a Type A influenza virus.

In humans, the flu is a respiratory infection caused by the influenza virus (in some other animals, such as birds, the flu acts primarily in the intestinal tract). There are three basic types of influenza viruses that affect humans, referred to as influenza virus type A, B and C. Type C influenza is not a significant source of disease, and while type B influenzas can cause serious illness, only type A influenza strains are known to cause pandemics.

Type A influenza viruses are broken down into subtypes based on the specific features of two proteins that project from their surfaces. (See illustration above.) These proteins, called hemagglutinin and neuraminidase, each have several possible variations. Influenza A viruses can have any of 16 H subtypes and 9 N subtypes, but only certain subtype combinations are associated with serious illness. Hemagglutinin is involved with how the influenza virus gains entry to a cell while neuraminidase is involved with the release of newly formed copies of the virus from the cell. 

Any particular type A influenza virus is named for its specific H and N subtype variations. For example, the current avian influenza is described as HPAI A/H5N1 meaning, “highly pathogenic avian influenza type A subtype hemagglutinin subtype 5, neuraminidase subtype 1,” usually just called H5N1 for short. Influenza viruses may be further identified with the date and presumed geographic origin of a particular strain.

It’s important to note that it is possible for an H5N1 virus to exist that is not highly pathogenic. For example, many H5N1 strains have been circulating in the bird population for many years without causing serious problems. It’s the combination of a virus’s HN structure and the specific genetic content that combine to define its overall characteristics, including its pathogenicity for any particular species.

Soldiers being treated at an influenza clinic at Fort Riley, Kansas during the 1918 "Spanish Flu" pandemic.

The most recent pandemics occurred in 1957 and 1968, claiming a total of more than 3 million lives. The "Spanish Flu" pandemic, which ran from 1917 through 1919, was the greatest medical calamity in human history. Estimates range from 20 million to more than 80 million deaths worldwide, even though only an estimated 2.5 percent of those who were infected with the disease died.

Many experts fear that the highly pathogenic avian H5N1 strain that is spreading rapidly through the worldwide bird population may lead to a comparable pandemic. A grim statistic, however, is that the current human mortality rate for this particular influenza virus is currently more than 50%.

Originating in Southern China, the H5N1 virus has now been reported in Europe, Africa, Southeast Asia and the Middle East and experts agree that it will soon arrive in the United States - probably first in Alaska and then in California.

This H5N1 avian flu virus is exceptionally pathogenic, that is, it has a high potential for causing life-threatening and fatal disease. Fortunately, as of this moment, the virus has not yet mutated into a form that is easily transmitted from infected animals to humans, or from one human to another. Experts disagree on how likely such transmission will become in the future, but everyone agrees that the potential exists and should be taken seriously. For now, most if not all human cases of the H5N1 avian flu have involved direct contact with infected birds.

H5N1 avian flu migration pattern.

Whether the current bird flu will develop into a serious human pandemic remains to be seen. However, chances are good that even if it doesn't, the human population will experience some form of influenza pandemic in the coming years. While predicting the exact time and circumstances of a pandemic is akin to predicting the exact timing of a major earthquake, from a statistical perspective it’s overdue.

Public health experts say that if a pandemic does begin, then it is essential to limit contact with others and to stay indoors as much as possible. Companies are creating contingency plans for some workers who can "telecommute" from home through electronic means. Essential workers who cannot communicate electronically may be advised to work in shifts so that fewer workers are present at any physical site at any given time. This simple concept, called “social distancing,” can be extremely important in limiting the spread of infection.

But jobs that depend on being out in the world, including service providers, delivery people and others supporting our healthcare, social and business infrastructure, may be temporarily inaccessible. Michael Leavitt, Director of the U.S. Health and Human Services Administration, has recently issued a statement that Americans should stockpile enough food and essentials to last at least 2 weeks in case they are ordered to "shelter in place" to help stop the spread of an avian flu outbreak. This may be particularly important for individuals who rely on medications, such as insulin, to maintain their health. If deliveries of essential goods are shut down for an extended period of time, then having a stockpile of prescription medications on hand for all family members is vital.

Some companies and individuals have taken to stockpiling Tamiflu®, an antiviral drug from Roche Laboratories that interferes with the ability of type A influenza viruses to cause infection. The U.S. government has stockpiled millions of doses of Tamiflu to use in the event of a major flu outbreak. However, some strains of the H5N1 influenza virus have already mutated to reduce the effectiveness of Tamiflu. A series of articles in the New England Journal of Medicine documented Tamiflu resistance to the highly pathogenic H5N1 strains that have developed in Vietnam (see de Jong MD et al. Oseltamivir Resistance During Treatment of Influenza (H5N1) Infection, New England Journal of Medicine. 2005; 353(25): 2667-72.

Please note that this information is provided for educational purposes only and is not intended to act as a substitute or replacement for proper health and medical advice from a trained and licensed professional healthcare provider. If you are ill, or are concerned about your health, please contact an appropriate healthcare professional.

ViraWall is not a medicine. It is not intended to prevent or cure avian influenza. However, its active ingredients have been shown to nutritionally support the body's natural resistance to viral challenges by powerfully blocking some viruses, including tested strains of type A influenza, from entering cells.

ViraWall is a nutritional supplement that may help play an important role in maintaining health. However, it should not be considered a substitute or alternative for proper medical diagnosis, advice or treatment.