Strangely enough, there are three groups most likely to die from some strains of influenza, the weakest, oldest, and the strongest. The flu itself is seldom life threatening, at worst requiring some people to be put on a respirator until their body can overcome the virus infection, but Type A H1N1 and some other flu strains can cause the body’s immune system to overreact to the infection and actually damage the body by the resulting inflammation.

Cytokine Storm

A young person with a healthy immune system can die of the flu due from something doctors call a cytokine Storm.

Cytokines are tiny proteins manufactured in immune cells and distributed through the bloodstream triggering an immune reaction among all cells. Cytokines aren’t a single chemical and can include such things as interleukin which is known as a drug of last resort for treating some infections such as those caused by viruses.

Influenza, like the common cold, is caused by a virus rather than a bacteria and therefore there is no treatment which directly attacks the infection. Antibiotics only treat bacterial infections, so the body’s own Cytokines are the only way to defeat the flu.

But sometimes Cytokine-producing cells are overstimulated and produce too many Cytokine chemicals which cause damage to the body, sometimes even attacking the body’s organs and leading to death.

This can happen in very healthy individuals whose immune system is too strong, or in the very young and very old where the body is less able to withstand even mild floods of the powerful chemicals.

Cytokine Storms can also occur in other infections of the respiratory tract such as SARS or Hantavirus where the immune reaction causes the lungs to fill with fluids.

Not all flu strains cause the extreme reaction but with a new influenza strain each year there is no way to predict when the next dangerous infection will become common.

The treatment

Fortunately on the near horizon is a new drug class which can reduce the storm of vital immune system chemicals below the danger level. Sphingosine-1-phosphate regulates the production of Cytokines in the body and thereby gives the body time to overcome the underlying infection.

Sphingosine analogs are still being tested but in the meantime, it is important to note that cholesterol-fighting drugs known as statins can also interfere with Cytokine production and therefore can help reduce deaths in severe influenza cases where the immune system is actually life threatening.

There is no guarantee that oral statins will save someone with an overactive immune system but they are relatively safe, especially when taken for short periods as would be the case in such infections. It is important to remember that statins are not anti-bacterial or anti-viral, but just happen to alter the body's immune response by reducing inflammation.

The University of Minnesota's study looked at the mortality rate for those who were already taking statins vs those who weren't and they found that the number of survivors was nearly double in the statin group.

Whether this would occur if someone was given statins during the flu episode is unknown but it is unlikely to cause harm and if it is their anti-inflammatory action which helps people survive flu then it is more probable that taking it when you have the flu might help reduce the chance of death.

One reason not to take statins routinely is that they reduce the effectiveness of the flu vaccine presumably because they reduce the body's immune reaction which is how vaccines work, by stimulating the body to produce antibodies which kill the infection. the body will usually defeat any infection given enough time and vaccines give the immune system a head start.