It can't. Doctors are in widespread agreement on this. Influenza virus is made from dead virus, which means it is not capable of launching an infection in your body.
Nonetheless, physicians and other health-care workers know they'll hear whining this year from patients who fear getting the flu shot they need. Now that the vaccines are recommended for babies, such unfounded worries become even more serious — they could prevent some of the most vulnerable from getting the protection they need.
"There is a prevailing myth that the vaccine causes the flu, and it bothers me," says Dr. Richard Kent Zimmerman, an associate professor of family medicine and clinical epidemiology at the University of Pittsburgh. "It particularly bothers me because, in the 1990s, there were 36,000 deaths annually in the United States from flu. We were fortunate we've had a couple of milder years since then, but we may not have a mild year this year."
Zimmerman is the author of the study of 1,383 people, age 66 and older, which found that 38% of unvaccinated people feared that they would get the flu from the vaccine. Among the vaccinated people in the study, published in January in the American Journal of Medicine, only 6% believed the myth.
According to the CDC, the flu shot can cause only mild symptoms such as soreness in the arm, a low-grade fever and body aches.
"You would not get a cough, runny nose, congestion or sore throat," says Jeffrey A. Goad, an assistant professor of clinical pharmacy at the USC School of Pharmacy. If you develop more severe symptoms, you probably contracted a virus about the time you received the flu shot, Goad says.
Because the elderly are more likely than other age groups to develop a low fever from the flu vaccine, they often are more reluctant to get the shot, says Stella Henry, a nurse and founder of the Vista del Sol Care Center in Culver City. Officials at the skilled nursing and assisted living center have promoted flu vaccination in recent years, because flu deaths most often occur in the elderly.
"We certainly experience residents who, after they have the shot, get a slight temperature," Henry says. "But we're pretty pro-flu vaccine. I start talking about it in August. If an elderly person gets the flu, they really get sick."
Thelma Zigler, a Vista del Sol resident in her late 70s, got her flu shot a few weeks ago. She says she once feared the vaccine too. But in the 1960s, while operating a drugstore with her husband, a doctor in the office next door to the pharmacy walked in one day, syringe in hand.
"Everyone back then said, 'Don't take it; you'll get sick,' " Zigler recalls. "But the doctor said, 'I want you to have a flu shot. You take care of my patients, and I don't want you getting sick.' I've had one every year since, and it has never made me sick. But some people make up their mind that it's going to make them sick, and you'll never change it."
The vast majority of Americans lining up for flu vaccines this year will receive the shot, including the newest group considered a "high risk" for influenza — babies ages 6 to 23 months.
Last month, a CDC advisory committee recommended adding annual flu shots to the childhood immunization schedule. The CDC still must formally enact the recommendation, but many doctors are expected to comply this year with the change.
Although influenza rarely kills babies, it can cause serious complications such as pneumonia. According to the CDC, 17,000 children under the age of 2 are hospitalized each year from flu complications, making this age group as likely to be hospitalized for flu as people age 65 and older.
Preventing flu in this age group may also spare more adults from getting sick. "A lot of preschool-age children bring flu home and give it to others in the family," Zimmerman says.
Federal health authorities had discussed recommending the flu vaccine for babies for several years, but held off because of the logistics involved. Babies already receive well over a dozen shots in the early years. Under the flu shot regimen, a baby's first flu vaccination would require that two shots be given a month apart. The second dose would be given before December, if possible. Only one shot annually would be required thereafter.
"The second dose is a challenge," Zimmerman acknowledges. "But a number of doctors' offices are setting up express services where you can just see a nurse for the vaccine, some even during evening hours. A physician doesn't have to see the child in order for the child to have a flu shot."
As in adults age 65 and older, some babies may have a slight fever from a flu shot.
But Zimmerman urges Americans to put the importance of vaccination over inconvenience and minor side effects.
"The number of deaths in adults and hospitalizations is the reason we use the vaccine," he says. "A flu shot is something fairly simple that is going to be cost-saving. There are so many benefits to vaccination. A flu shot costs $9 wholesale. That's a pretty good deal in my book."
Adapted from an article written by