Flu season is here, which means doctors’ offices and drug stores around the nation are promoting flu shots. Some swear by the flu shot, flocking to get their annual shot without a second thought, while others resist being vaccinated, citing health concerns. With so many strong voices out there, it can be hard to decide what’s best.
So here’s a quick look at some flu shot facts to help you sort fact from fiction.
What is the flu shot?
The first flu shot was invented in 1938 by Jonas Salk, the same man who invented the polio vaccine. Like all vaccines, the flu shot uses a small amount of an inactive virus to spur the immune system to produce protective antibodies that prevent recipients from contracting that virus.
How does it work?
The immune system mistakes the dead virus for the real thing, prompting the body to produce protective antibodies that prevent recipients from succumbing to that virus if exposed to it in the future.
How effective is it?
Because the flu vaccine combats only certain strains of influenza — usually three, though that has recently increased to four — its efficacy varies from year to year, depending on what strains are most dominant in any given year. In addition, the vaccine’s effectiveness varies among individuals. That said, the Centers for Disease Control estimates that a season flu vaccine can reduce the risk of contracting the flu by between 70% and 90%.
Does it work immediately?
No. It takes about two weeks for the body to produce the necessary antibodies to fight off future encounters with the virus. The earlier in the season you get a flu shot, the better the chance that your body will have its defenses in place if an when you need them.
Can it make me sick?
No. The influenza virus present in a flu vaccine is not live, and is incapable of transmitting the flu. Some people do report feeling mildly fatigued for a day or two after receiving a flu vaccine.
I heard the flu shot contains mercury. That sounds dangerous. Is it true?
At one time, vaccines included a small amount of a type of mercury called thimerosal, which was used as a preservative to ensure freshness. Experts say that, unlike the more common methyl mercury, thimerosal is harmless. However, vaccine producers stopped using thimerosal a few years ago due to concerns among some parents that the compound may be responsible for causing autism in children. This belief has been discredited in recent independent studies, but vaccine manufacturers have opted to stick with less controversial preservatives.
I heard flu shot is dangerous for people with egg allergies. Is that true?
Some flu vaccines are produced inside of eggs and may contain trace amounts of egg protein. Allergists agree that the risk of becoming ill from such a small amount of egg protein is slim. For those who are still concerned, it is possible to find flu vaccines that were not made using eggs.
If the flu shot is safe, why can’t I get it when I’m sick?
Being sick will not increase the likelihood of becoming sick from the flu vaccine. Getting the flu shot when you’re sick can reduce the effectiveness of the vaccine, though. When you’re sick, your immune system is already working hard to make you well. An already compromised immune system will not be able to produce sufficient antibodies in response to the inactive flu strains from the vaccine, so you may not be be fully protected if and when you encounter the real thing.
What about pregnant or nursing women? Is it safe for them?
Doctors say it is completely safe for pregnant women and nursing mothers to receive a flu shot.
What about babies?
The flu shot is considered safe for babies over six months of age, and doctors say that children up to the age of two are among those who are most in danger of dying from contracting influenza.
What if I’m afraid of needles?
A nasal spray version of the vaccine is now available for those who hate needles.
The flu is no big deal. Is it really worth the expense and trouble?
Each year, in the United States, about 500,000 people die from the flu, and millions of others become severely ill to the point of hospitalization. While most of these deaths are among very young children and the elderly, doctors insist that as many people as possible should be vaccinated. This reduces the overall cases of the flu, which protects the most vulnerable among us.