November may bring thoughts of Thanksgiving and Christmas shopping, but it also is the time Americans should protect themselves against one of the top 10 killer diseases: influenza.

That's the advice from the federal Centers for Disease Control, the agency that monitors flu outbreaks across the country and issues recommendations on how to ward off the influenza virus.Widespread outbreaks of flu usually do not start until December, according to the CDC's Immunization Practices Advisory Committee. Therefore, November is the best time to get flu shots, which usually take about two weeks to protect against the flu virus.

Last year, the United States experienced its worst flu epidemic in five years, with outbreaks beginning in early December. Federal health officials estimated the death toll at 52,000, about 10,000 more than in non-epidemic years.

In some weeks, more than 1,000 people died of influenza and its principal complication, pneumonia.

Flu vaccinations are especially recommended for those over 65, and adults and children with chronic disorders of the pulmonary or cardiovascular systems, including children with asthma.