SPRINGFIELD, Ill. -- While a vaccination against influenza is encouraged for all those wanting to avoid the sniffles, cough, fever, sore throat and body aches associated with the disease, recent studies have found a flu shot is especially important for infants and toddlers who are as likely to be hospitalized with flu complications as are people 65 years and older.

Dr. Eric E. Whitaker, state public health director, today issued a reminder that all healthy children 6 months to 23 months of age, as well as their older siblings, parents and out-of-home caregivers should get the vaccination.

"With predictions by the U.S. Centers for Disease Control and Prevention (CDC) that this year's influenza season may be more severe than in the recent past, it is more important than ever that children get their flu shots now," Dr. Whitaker said. "A flu shot can help prevent needless hospitalizations and deaths."

While so far in Illinois this year there have been few cases of the flu reported, outbreaks of influenza have been reported in a number of states, including Colorado where there have been more than 6,300 confirmed cases and at least five children have died.

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

The American Academy for Pediatrics first recommended flu shots for children 6 months to 23 months of age in 2002. Unlike the one annual shot given for most people, the first-ever flu immunization for any child 6 months to 9 years of age requires two-doses of vaccine because their initial shot doesn't offer enough protection. After that, it is recommended that they receive annual shots because there are different strains of influenza each year.

The vaccine has not been approved by the U.S. Food and Drug Administration for infants under 6 months of age, but their relatives and caregivers should be vaccinated so they don't spread the virus to the newborns.

It has been a recommendation for years that senior citizens get flu shots because they are at high risk of death from the flu, but now doctors are counting on the vaccine to curb the number of toddlers and infants who have to be hospitalized with influenza.

"Flu can be a serious illness and each year it kills an average of 36,000 Americans and requires 114,000 people to be hospitalized with complications, including pneumonia," Dr. Whitaker said. "A simple flu shot can help prevent a person from getting the virus, as well as helping to limit the number of people who spread the disease."

In addition to young children, the 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.

Those who care for or live with persons at high risk should also 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.

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 CDC expects to circulate in the United States this flu season: A/Moscow, A/New Caledonia and B/Hong Kong.

Some states have reported a Fujian strain of the flu this year, but CDC believes this vaccine will provide cross protection against this strain.