Influenza and its enemies: government badly wants Americans to line up for annual flu shots, but though highly touted, there are indications the vaccines may not be as effective as advertised.(HEALTHCARE)(Cover story)

According to the Centers for Disease Control, the flu sickens over 200,000 people each year and kills 36,000 more. To fight this menace and to raise awareness about the availability of the flu vaccine, the Department of Health and Human Services declared the week of November 27 to December 3 to be "National Flu Vaccination Week."

In the press release announcing "Flu Vaccination Week," HHS noted that the United States has up to 115 million doses of influenza vaccine on order and that the vaccine "is especially recommended for those 50 and older, those with chronic illnesses, pregnant women, children 6 months until their 5th birthday, health care workers, and household contacts and caregivers of high-risk persons." Moreover, HHS pointed out, flu vaccination is "a smart choice for anyone wishing to avoid becoming sick--or spreading illness at home, the office, or on holiday visits with friends and family."

That's the conventional wisdom anyway. But what if the flu vaccine was largely irrelevant? While vaccinations, when used appropriately, have proven to be remarkably effective in fighting a number of debilitating illnesses, the flu vaccine may not be nearly so effective.

The Wages of Mutation

To get a better picture of how well flu vaccines may work, it helps to understand a little bit about the virus that causes the disease. Influenza is caused by a family of viruses known in scientific literature as orthomyxoviruses. These are tiny little pirates, usually spherical in shape and no more than 80 to 120 nanometers in diameter. In order to spread, these tiny pirates invade host cells and hijack the cell's internal machinery, forcing it to produce the bits and pieces needed to make new viruses. When these are assembled into new viruses, they exit the host cell and move on.

Fortunately, the body's immune system can usually detect and destroy viruses, after it learns to recognize them. The practice of vaccination takes advantage of this immune response by introducing either dead or very weakened viral elements into the body. After the vaccination, the immune system learns to recognize the viral matter that has been introduced and is able to respond effectively should a real infection occur.

The trick to this is that the immune system can only respond to what it recognizes, and orthomyxoviruses have a nasty habit of mutation.