 |  |  |
Influenza, or “the flu” causes high fevers and body aches. It also kills thousands of
people each year. In 1918, an outbreak of flu killed as many as 50 million people. Influenza
is caused by a virus that is always changing, and the danger of a new, deadly strain of the
virus is always looming.
The genetic material of influenza contains the instructions for making new viruses.
Influenza viruses are special because have eight separate pieces of genetic material. This
lets them mix and match.
Imagine picking eight black cards and eight red cards out of a deck of cards. You have
two sets of cards, one all black and one all red. Now shuffle them together. If you pick up
eight cards, some of them will be black and some of them will be red. You have a new
combination of black and red.
That’s what happens when two different influenza viruses infect the same cell. The
segments can shuffle themselves into new combinations, producing new kinds of viruses.
Some of these new viruses may be harmless, and some of them may be deadly. Scientists
are constantly on the lookout for new influenza viruses, hoping to prevent the next
outbreak of killer flu.