Vaccines are complicated, so it's easy to see why there are misunderstandings---and no vaccine is as misunderstood as the influenza vaccine. Myths abound surrounding the flu shot, and the reasons people give for avoiding it are sometimes so deeply entrenched that it's difficult to convince them of the truth. But the fact is, the flu vaccine protects against a deadly virus that hospitalizes over 200,000 people each year; of those, 36,000 people die. In contrast, according to the Centers for Disease Control and Prevention, the risk for a severe reaction to the influenza vaccine is approximately one to two in 1 million people.
Myth 1: The Shot Will Give You the Flu
The influenza vaccine is available in two forms: an injection and a nasal spray. It is impossible for either form to infect a person with the flu, because the flu shot is made of inactivated (killed) virus, and the nasal spray is made of weakened virus that, according to Dr. Edward Sherwood of the Texas Medical Association, cannot grow in the lungs or make you ill.
It can take 10 to 14 days for the body to be fully protected after receiving the vaccine, so during flu season it's quite possible to become ill during this lag time. But it's strictly coincidental---the vaccine did not cause the flu.
Myth 2: It's Better to Just Get the Flu
Some people believe that, with or without the vaccine, they're going to get sick anyway, so it's better to just go ahead and get the flu naturally. These people don't understand how the vaccine works or the seriousness of the disease. Although it's true that approximately two to three out of 10 people receiving the vaccine may still catch the flu, the course of their illness will be much milder and of shorter duration than if they had not received the vaccine. People who catch the flu naturally, on the other hand, face up to two weeks recovery time and complications beyond respiratory symptoms.
Myth 3: The Flu Vaccine Contains Mercury and Causes Autism
The rumor that some vaccines contain mercury and that mercury causes autism has run rampant in recent years and is extremely unfortunate. It is entirely untrue, yet parents hear the word "autism" and immediately determine that vaccines must be harmful. The myth is fueled by misinformation and confusion over names.
To set the record straight, no vaccine contains mercury. Even if one did, mercury does not cause autism. In the case of the influenza vaccine, Thimerasol is used as a preservative in some flu vaccines---those that come in multiple-dose containers. As it is metabolized by the body, Thimerasol changes into ethylmercury, which harmlessly leaves the body within four days. The type of mercury that is harmful is methylmercury which, while it does not cause autism, can cause heavy-metal poisoning. Vaccines have no association with this substance.
If a person does not feel comfortable receiving the flu vaccine with thimerasol, he should simply ask his health care provider if a single-dose vaccine (without preservative) is available.
Myth 4: "I Never Get the Flu"
Approximately 20 percent of the population catches the flu each year. Of those infected, many won't develop any symptoms but will still be contagious and may infect others. Chances are, even if a person thinks she's never had influenza, she's probably been infected without knowing it. Getting immunized will not only protect the person, but will also protect others in the community with whom the individual interacts.
