Flu Breakthrough: The Search for a Universal Vaccine
Tired of having to get a different flu shot -- or two -- every year? Someday one shot may protect us against all the strains.
The 1918 Flu Pandemic continued...
Researchers have since discovered one reason the 1918 flu strain was so
lethal. Unlike most of today's flu viruses, which can only copy themselves in
the upper respiratory system (mouth, nose, and throat), the Spanish flu was
able to replicate inside the lungs. As infected peoples' lungs filled with
fluid, they suffocated to death, sometimes within a day or two of showing
symptoms. While the H1N1 swine flu virus is also able to directly infect the
lungs, researchers note that so far it has not been nearly as deadly as the
Recently, researchers have discovered something else about that 1918 strain
-- it's the genetic granddaddy of the H1N1 flu strain that's making headlines
today. They traced the 2009 H1N1 virus back to the 1918 Cedar Rapids Swine Show
in Iowa, where many pigs developed a respiratory infection that looked an awful
lot like the influenza virus that was spreading like wildfire among humans.
Over the next 90 years, that virus swapped genes a few times with other flu
viruses, and re-emerged as the H1N1 flu strain we're dealing with today. The
H1N1 flu strain circulating now is nowhere near as lethal as its
predecessor, but unlike the H1N1 flu, it tends to be more dangerous to young
people, and researchers think they've figured out why. Older people
(particularly those born before 1950) have been exposed to the swine flu's
relatives, and their bodies have built up antibodies to the virus. Young people
don't have that same immunity.
The History of the Flu Shot
The 1918 pandemic was particularly vexing to doctors because they had
nothing at their disposal to prevent or treat it. Researchers didn't even
discover the influenza virus until 1933, and a working vaccine wasn't released
until a decade later. Even today, with 21st century medical technology at our
disposal, flu vaccination involves a lot of guesswork and uncertainty.
Researchers from around the world have to look at flu surveillance reports
several months in advance, anticipate which strain will be prevalent in the
coming season, and hope their prediction is correct. They still haven't been
able to create one vaccine that can target all strains for all seasons.