Flu Shot Effectiveness

Getting a flu shot is the most effective way of preventing seasonal influenza. It's still possible to get the flu after being vaccinated, but it will greatly reduce the likelihood. The Centers for Disease Control offers many helpful facts for flu season.

Factors

• The flu shot is most effective when the vaccine viruses are a close match to the flu viruses currently in circulation. Effectiveness rates also vary from person to person based on age and general level of health.

Healthy Adults

• If the flu vaccine is a close match to circulating viruses, the flu shot is 70 to 90 percent effective in preventing the flu in healthy adults.

The Elderly

• The flu shot is less effective in preventing flu in adults over the age of 65.

Children

• The flu shot is 66 percent effective in preventing influenza in young children. Older children receive greater protection from the shot.

Other Infections

• The flu shot provides protection against only seasonal influenza. It will not help prevent 2009 H1N1 flu or any non-flu viruses such as the common cold.

Increasing Effectiveness

• You need to get a new flu shot each year, preferably by October or November. Since the vaccine will not completely protect you against the flu, it's important to continue common sense prevention measures.