Why Flu Shots Matter

Flu shots are important because the virus that causes the flu changes constantly, and a new strain appears almost every spring.

"So the shot that protects you one year won't necessarily protect you the next," says Suzanne F. Bradley, M.D., an infectious disease specialist in Ann Arbor, Mich. Scientists track mutations of the virus and develop new vaccines against it.

Effects can be severe

The flu can be deadly in older individuals. Changes in your immune system increase your chance of getting it, and the flu's effects can be especially severe if you have a chronic lung or heart condition. "The flu vaccine is 90 percent effective in preventing deaths and 80 percent effective in preventing hospitalizations," Dr. Bradley says. "If everyone who should have one got one, it would save lives."

Your body can take weeks to respond to the vaccine. "That's why it's important to ask for a shot in October or November before the flu season starts," says Dr. Bradley. "But even if you miss your shot in the fall, you should still get one if there is an outbreak in your area."

The shot doesn't guarantee you won't get sick, nor will it protect you against other respiratory diseases, Dr. Bradley says, "but it's important to remember that the flu kills, colds don't." 

The flu shot may not be for you if you are allergic to eggs, are ill with a high fever, or have had a severe reaction to the flu vaccine in the past. If you are unsure if you should get the shot, consult your health care provider. In addition to the injected vaccine, a nasal spray vaccine is available for children and adults ages 2 to 49.

Warding off pneumonia

Immunization also can lower the risk of pneumonia. Many kinds of bacteria can cause pneumonia, and the vaccine won't protect you against all of them. But if you are over 65, talk with your doctor about when to get the shot and when to get a booster, because it can protect you against a number of them.

Dr. Bradley says getting a pneumonia shot is even more important today. When bacteria cause pneumonia, "we use antibiotics to treat it. Some of the bacteria are becoming resistant. So you really gamble if you don't get the shot. There's a chance that the medicine won't work" if you wait until you have pneumonia.

Viruses also can cause pneumonia. There is no immunization against those types of pneumonia, which don't respond to antibiotics.