Influenza, commonly known as flu, affects as many as one in five Americans each year, while more than 200,000 get hospitalized due to seasonal flu-related complications, yet many still do not get vaccinated, reports said.

According to experts, the best way a person can be protected against flu is to get vaccinated. The Centers for Disease Control and Prevention (CDC) recommends everyone ages six months or older get vaccinated.

"Some don't believe the flu is a real threat to them. Others don't trust the vaccine to do its job," says Dan Dworsky, MD, medical director for Scripps Clinic and Scripps Coastal Medical Center in San Diego, California. "It's unfortunate that there is still a lot of misinformation about the flu and vaccines designed to protect the public from it."

Every season, Dr. Dworsky leads a campaign to vaccinate and educate patients and staff. That effort includes dispelling flu vaccine myths like these:

Myth #1. The flu vaccine can give you the flu.

The injectable influenza vaccine is composed of inactivated virus particles, so it can't transmit infection, according to Dr. Dworsky. "It's still possible for someone to get the flu in the days following vaccination," he says. "It takes about two weeks after vaccination for antibodies to develop in the body and provide protection against influenza."

The side effects of the vaccine could also be to blame for this myth. All vaccines stimulate the immune system and can occasionally cause mild muscle aches and a low-grade fever. "These symptoms are very rare, mild in nature and are nothing compared to influenza illness," Dr. Dworsky emphasizes.

Myth #2. The flu vaccine is dangerous.

"The flu vaccine is extremely safe for most people," asserts Dr. Dworsky. "That being said, there are certain populations that are at special risk." If you have a severe, (life-threatening) allergy to eggs or have had Guillain-Barré syndrome, the CDC recommends you skip the seasonal shot. People who are moderately or severely ill should usually wait until they recover before getting the flu vaccine.

Myth #3. If you are young and healthy, you don't need to get vaccinated.

Even if you are not at risk for severe complications from the flu, you can still pay a hefty price if you get it. Having the flu can result in a significant loss of work time. "Some people need up to 10 days off in order to recover," says Dr. Dworsky.

Vaccines also create herd immunity. Because influenza is transmitted from person to person, when a critical mass of community members is immunized against it, most members of the community are protected because there are fewer sick people passing the illness to others. "Think of it like tic-tac-toe," explains Dr. Dworsky. "The more Xs on the grid, the less likely you are able to get three 0s in a row."

Myth #4. The vaccine isn't effective.

The flu shot isn't 100 percent effective at guarding against the flu. In fact, a study published in The Lancet examined the efficacy of the most popular flu shot in the United States-the trivalent inactivated vaccine. The results indicated it was effective about 59 percent of the time.

"That's less effective than previously thought. But the findings shouldn't discourage people from getting the vaccine or derail the ongoing efforts to immunize people against influenza," says Dr. Dworsky. "The flu vaccine needs improvement, but it remains the best defense we have against a potentially lethal disease."