However, 40 years elapsed between the first flu pandemic of the 20th century and the second, followed by 10 years between the second and third - which can hardly be viewed as a predictive pattern.

Scientists made similar warnings over the SARS (severe acute respiratory syndrome) virus in 2003, which was also expected to become a major pandemic. Like H5N1, it started in Asia before spreading to the West, where it seemed set to reach Canada. The Canadian health authorities - so concerned by the threat - allowed the United Nations and the WHO to take over the day-to-day responsibility for controlling any outbreak.

In the event, SARS proved to be a damp squib, killing fewer than a thousand people worldwide.

Why flu drugs don’t work All flu viruses change antigenically to evade recognition by the host’s immune system. These modifications take place rapidly and often - a flu virus can mutate up to a million times more often than a DNA virus (Vaccine, 2002; 20: 3068-87). Vaccine designers at the WHO Global Influenza Program have to prepare new antigen formulations every year, often nine months ahead of the next major flu outbreak. Their role is therefore mainly predictive as they try to second-guess what the new flu virus strain will be to achieve a perfect antigenic match. Only the vaccine that is a perfect match to the virus can combat it, and achieving this is almost impossible, given the infinite permutations that the virus can undergo (Lancet, 2005; 366: 1139-40).

Ironically, and not surprisingly, the perfect flu vaccine is always a year too late.

Over the past 40 years, the drug industry has produced four major antiviral drugs to combat flu - amantadine in 1966, rimantadine in 1993, zanamivir in 1999, and oseltamivir, marketed as Tamiflu, also in 1999 - and resistance to all four is regularly reported (Lancet, 2000; 355: 827-35; J Infect Chemother, 2003; 9: 195-200).

The hope, therefore, that any one of these can combat a virus that has not even crossed over into humans is futile. And yet, Tamiflu is consistently promoted as the main weapon against the H5N1 virus. The US government has placed an order for 20 million doses at a cost of $2 billion (USA Today, October 8, 2005), while the UK government is ordering 14.6 million doses, even though America’s advisors at the Centers for Disease Control and Prevention (CDC) in Atlanta, GA, have gone on record as stating that there is no vaccine to protect people against the H5N1 virus (www.cdc.gov/flu/avian/gen-info/facts.htm).

Protecting against avian flu At its worst, the avian flu has killed fewer than half the number of poultry workers who have been infected, according to WHO statistics. However, if it truly is as lethal as we have been warned, it surely should have eventually killed everyone it infects. This suggests that a healthy body, and a properly functioning immune system, can withstand any viral attack.

* Supplements

- Vitamin A is one of the most important nutrients for establishing a healthy immune system. It helps maintain the surface tissues that line the eyes as well as the respiratory, urinary and intestinal tracts which, in turn, act as physical barriers against bacteria and viruses (Clin Infect Dis, 1994; 19: 489-99; J Nutr, 1995; 125: 1211-21).

It also helps to regulate the immune system by enabling lymphocytes - the white blood cells that fight infection and disease - to do their job more effectively.