SPRINGFIELD, Ill. – The cooler temperatures not only signal the beginning of fall, but the nearing of flu season. To avoid influenza, Dr. Eric E. Whitaker, state public health director, today urged Illinoisans, young and old, to get their annual flu shot.

"Each year hundreds of Illinoisans are hospitalized due to complications of influenza," Dr. Whitaker said. "The good news is that this year's supply of the vaccine is plentiful and readily available so anyone wishing to get a flu shot can do so."

The flu season typically runs from November until April and peaks between January and March. October is the optimal time to be vaccinated because it takes about two weeks for immunity to develop and provide protection. The vaccination, however, can be given at any time during the flu season.

Although anyone who wishes to avoid influenza should be vaccinated, Dr. Whitaker strongly recommended the shot for those most at risk of developing serious complications from influenza.

Following are those considered most at risk and for whom a yearly flu shot is recommended:

• Persons 50 years of age and older;
• Residents of nursing homes and other long-term care facilities that house persons of any age who have long-term illnesses;
• Adults and children 6 months of age or older who have chronic heart or lung conditions, including asthma;
• Adults and children 6 months of age or older who have needed regular medical care or hospitalization during the past year because of metabolic diseases (for example, diabetes), chronic kidney disease or a weakened immune system, including immune problems caused by medicine or infection with human immunodeficiency virus (HIV/AIDS);
• Children and teenagers 6 months to 18 years of age who are on long-term aspirin therapy and therefore could develop Reye syndrome after the flu; and
• Women who will be more than three months pregnant during the flu season.

In addition, those who care for or live with persons at high risk should get a flu shot, including:

• Health care workers (doctors, nurses, hospital and medical staff, personnel of nursing homes or chronic-care facilities, providers of home health care), including emergency response workers, who have contact with patients or residents;
• Household members, including children, who live with persons in high-risk groups; and
• Care-givers for children younger than 2 years of age.

Again this year, the state is encouraging flu shots for healthy children 6 months to 23 months of age because of increased rates of influenza-related hospitalizations in this age group. Unlike the annual flu shot provided to most people, children 6 months to 8 years of age receiving their first-ever influenza vaccination require two doses a month apart to build immunity.

"Influenza vaccination is the best way to prevent influenza and its severe complications," Dr. Whitaker said. "While the vaccine does not always protect a person from getting the flu, it typically reduces the severity of the illness and the risk of serious complications." The vaccine is 70 to 90 percent effective in preventing influenza among -more- add 2 healthy adults 65 years of age or younger.

Besides the flu shot, Dr. Whitaker also recommended that the elderly receive a vaccination against pneumococcal pneumonia and others with chronic medical conditions should check with their physician about the vaccine. Unlike the flu shot, the pneumococcal vaccine is usually given only once for lifetime protection rather than yearly.

Dr. Whitaker said the flu vaccine is safe, effective and made from killed influenza viruses, which cannot cause the flu. Less than one-third of those who receive the shot have some soreness at the vaccination site and about 5 percent to 10 percent experience mild side effects, such as headache or low-grade fever, for about a day after vaccination. People who are allergic to eggs or who have an acute illness with fever should check with their physician before receiving the vaccine.

Influenza, commonly called the flu, is caused by viruses that infect the respiratory tract and spreads from person to person when an infected person coughs or sneezes. Typical flu symptoms include fever (usually 100 degrees F in adults and often higher in children), dry cough, runny or stuffy nose, headache, muscle aches and extreme fatigue.

After a person has been infected with the virus, symptoms usually appear within one to four days. The infection is considered contagious for up to five days after symptoms appear and illness usually lingers for a week or two. Each year, an estimated 10 percent to 20 percent of the population contracts influenza.

Flu shots must be given annually, since scientists formulate a new vaccine each year from inactivated influenza viruses in circulation at this time. This year's shot is designed to provide protection against three strains of flu that the federal Centers for Disease Control and Prevention expects to circulate in the United States this flu season: A/Moscow, A/New Caledonia and B/Hong Kong.