Part 1 of 2
Viruses are among the nastiest creatures, if you can even call something that is not technically alive a creature, known to man. They replicate only within another living being and seem to serve no purpose other than to divide and destroy.
Flu is one of the most feared and rightly so. Influenza and pneumonia are the eighth-leading cause of death in the United States, according to the Centers for Disease Control. Every winter flu spreads, and this year seems to be particularly bad in South Mississippi, with many hospitals overwhelmed with cases.
Thankfully, scientists have developed a potent tool for fighting viruses: vaccines. Diseases like smallpox and polio that once tormented humanity are essentially gone. Others like measles and diphtheria are greatly reduced.
Vaccines have also proven to be very effective against the flu, yet many are wary about taking the shot. Our readers poll showed 54 percent had received a flu shot this year, while 26 percent said they haven’t because they don’t think it works and 18 percent haven’t because of concerns about taking the vaccine.
Perhaps some of the confusion about the efficacy and risk of the flu shot is because it’s complicated to understand what a flu shot does. We’re going to try to explain it as best we can.
Why it’s worse in winter
No one had proven why this was until 2007 when Dr. Peter Palese of New York led a study in guinea pigs that showed the animals transmitted the virus excellently at 41 degrees but not at all at 86 degrees, according to a New York Times story about the study. The virus also transmitted best at 20 percent humidity and not at all at 80 percent humidity.
It’s no coincidence that this has been an unusually cold and clear winter in South Mississippi, and we’ve seen a multitude of flu cases.
“Flu viruses are more stable in cold air, and low humidity also helps the virus particles remain in the air. That is because the viruses float in the air in little respiratory droplets, Dr. Palese said. When the air is humid, those droplets pick up water, grow larger and fall to the ground,” the Times story said.
How flu vaccines are made
There are actually three ways to do it, according to the U.S. Food and Drug Administration, but most commonly, vaccine viruses of the desired strain (we’ll cover the different types of viruses in the future) are grown in chicken eggs. Then they inject the viruses into fertilized chicken eggs and incubate them to let the virus reproduce. A fluid containing the virus is drawn from the eggs, and the virus is then “inactivated,” which means it can no longer reproduce. You can “kill” it with several methods, including heat, formaldehyde and detergents. A study published in 2010 in the Journal of Clinical Microbiology showed formaldehyde and a detergent called Triton X-100 worked best because they didn’t reduce the characteristics that make the vaccine effective like heat did.
As the CDC plainly states, “There is no live flu virus in flu shots. They cannot cause the flu.”
— By Charlie Smith. Part 2 will be published Saturday and will cover what vaccines do inside the body and the different strains of flu
