While it is important to get vaccinated against the flu virus as early as possible, it is never too late to reap the benefits of this vaccine. According to The Centers for Disease Control and Prevention, the peak months for the spread of the flu virus are January and February and the season can last into mid-May. Those at highest risk of complications from the flu are young children; people 65 and older; pregnant women; and people with health conditions such as heart, lung or kidney disease, or a weakened immune system.

"Adults age 65 and older face the greatest risk of serious complications and even death as a result of influenza. That is why it is so important that they get immunized. Even when older adults contract the flu after immunization, which can happen, those cases tend to be less severe and of shorter duration," says Dr. Mark Lachs, director of geriatrics at NewYork-Presbyterian Hospital.

"It is important that all children get immunized against this illness," says Dr. Gerald Loughlin, pediatrician-in-chief at the Phyllis and David Komansky Center for Children's Health at NewYork-Presbyterian Hospital/Weill Cornell Medical Center.

Dr. Lachs and Dr. Loughlin offer the following guidelines to help protect these most vulnerable populations from catching the flu this winter:

• Get vaccinated early. The flu vaccine is most effective when administered during the fall months, before the onset of flu season.

• It's never too late. The flu season begins in the fall and can last through the spring, so if you do not get vaccinated in October you can still be immunized in December or January.

• Know your options. A nasal vaccine is available for healthy children from age two and over, and for adults up to the age of 49. There are some restrictions so check with your doctor first.

• Get your family members vaccinated. The Centers for Disease Control and Prevention recommends that the following groups get immunized against the flu every year:

o Children beginning at six months of age

o Pregnant women

o People 50 years of age and older

o People of any age with certain chronic medical conditions such as asthma, diabetes, cardiovascular disease, and any form of immunosuppressive illness

o People who live in nursing homes and other long-term care facilities

o People who live with or care for those at high risk for complications from flu, including:

* Health care workers

* Household contacts of persons at high risk for complications from the flu

* Household contacts and out-of-home caregivers of children less than 6 months of age (these children are too young to be vaccinated)

Physicians and nurses at the Komansky Center for Children's Health at NewYork-Presbyterian Hospital/Weill Cornell strongly urge parents to have their children immunized early to make sure they have optimal protection during December and January when flu epidemics are at their peak.