By Dr. Carolyn Stratz

joe hu/town crier There was no shortage of flu shot vaccines this year, either nationally or locally. Registered nurse Mary Shoenky gives Los Altos Hills resident Steve Neil a flu shot at Draeger’s Market Saturday in Los Altos.

Q:Should I get a flu shot?

A: Welcome to the flu season, which in the United States is usually from November through April each year. During this time flu viruses are circulating in the general population, increasing your chances of catching one. An annual flu shot is the best way to reduce the chances that you’ll suffer from the flu this season.

Influenza is a serious disease, one that can affect people of any age. In an average year, the flu precipitates 114,000 hospitalizations. The vaccine is the primary means of preventing influenza and its complications, which include pneumonia.

Complications from the flu occur most commonly in patients over 65. Those under 65 but with certain medical conditions, including diabetes and autoimmune disorders, are also susceptible. It is therefore recommended that these two groups get vaccinated, as well as those over 50.

Flu viruses change from year to year, which, unfortunately, means you can get the flu more than once in your lifetime and also explains the need for a flu shot every year. Each season the vaccine is updated to include current viruses.

The best time to get a flu shot is October or November. You should avoid getting a flu shot too early in the season because protection can begin to decline within a few months after getting the shot. Once you get a flu shot, your body makes protective antibodies in about two weeks. However, because the vaccine simply attempts to match the virus strain and is not exact, it is possible to still contract the virus. Typically the virus prevents the flu in 70 percent to 90 percent of those receiving it, depending on health and chronic medical conditions.

The viruses in the flu shot are inactivated, so you cannot get the flu from a shot. While the risk of side effects from a flu shot is small, some may suffer an allergic reaction. The most common side effects are soreness, redness or swelling at the inoculation site and fever or aches. Make sure to let your doctor know if you are allergic to eggs or if you’ve had a severe reaction to a flu shot in the past.

Caroline K. Stratz, M.D., is an internist in private practice near El Camino Hospital. For more information, call 988-9975.