fluenza (the “flu”) is a common, often miserable, and sometimes very serious illness. The symptoms of classic influenza include the abrupt onset of fever, sore throat, headache, cough, muscle aches, and fatigue. Every year, influenza kills between 12,000 and 50,000 people in the United States.

Influenza viruses are constantly changing, but what doesn’t change is that flu shots are the best tool we have to combat influenza. Annual flu vaccination is recommended for everyone older than the age of 6 months. This is especially important for women who will be pregnant during the flu season, persons with chronic diseases or immunosuppressive disorders, and residents of assisted living or long-term care facilities.

How is influenza spread?

The primary mode of influenza transmission is through large, virus-laden respiratory particles called droplets. When an infected person coughs or sneezes, they generate droplets that can travel up to 6 feet or more. When someone near the infected person breathes the droplets in, they can settle on the mucous surfaces of the upper respiratory tract, which can lead to infection.

What are some of the complications of the flu?

Most people who develop influenza recover without any complications. However, the elderly, young children, and individuals with underlying medical conditions such as chronic heart or lung disease or diabetes are more susceptible to more serious complications. These complications can include pneumonia and the worsening of underlying medical conditions.

What are the best ways to prevent the flu?

Seasonal influenza infection is preventable. Annual vaccination against influenza is the best way to protect against serious illness.

We are often asked, “Can I get influenza from getting a flu shot?” The answer is “No,” the flu shot does not cause the flu. The influenza viruses contained in a flu shot are inactivated (killed), which means they cannot cause infection. Flu vaccine manufacturers kill the viruses used in the vaccine-making process, and batches of flu vaccine are tested to make sure they are safe.

Some additional steps you can take to prevent the flu include:

• Wash hands often with soap and water or an alcohol-based hand rub.
• Avoid touching your eyes, nose, or mouth. Germs and viruses that cause illness can be spread this way.
• Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash afterwards, and wash your hands.
• If you are sick with a flu-like illness, stay home for at least 48 hours after your last fever without the use of fever-reducing medicine.
• Find more tips at cdc.gov/flu/consumer/prevention.htm.

Influenza vaccines are very safe. Each year tens of millions of doses of vaccine are used in the United States and extensive surveillance confirms vaccine safety. In the U.S., because flu activity typically peaks between December and February, September and October are the best times to get vaccinated. Ideally, everyone should be vaccinated by the end of October, however; even after October, vaccination is still recommended because significant flu activity can continue into the late spring.