Influenza

Are You Protected?

The U.S. Centers for Disease Control and Prevention (CDC) recommends annual influenza vaccination for the following groups:

• all persons who want to reduce the risk of becoming ill with influenza or of transmitting influenza to others;
• all children aged 6 months through 18 years of age;
• all persons aged 50 years and older;
• women who will be pregnant during the influenza season;
• adults and children who have chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, hematological or metabolic disorders (including diabetes mellitus);
• adults and children who have immunosuppression (including immunosuppression caused by medications or by human immunodeficiency virus;
• adults and children who have any condition (e.g., cognitive dysfunction, spinal cord injuries, seizure disorders, or other neuromuscular disorders) that can compromise respiratory function or the handling of respiratory secretions or that can increase the risk for aspiration;
• residents of nursing homes and other chronic-care facilities;
• health-care personnel;
• healthy household contacts (including children) and caregivers of children aged <5 years and adults aged 50 years and older, with particular emphasis on vaccinating contacts of children aged <6 months; and
• healthy household contacts (including children) and caregivers of persons with medical conditions that put them at higher risk for severe complications from influenza.

Individuals with severe hypersensitivity to eggs or those who have had a previous vaccine-associated allergic reaction should avoid immunization.

Influenza vaccine is 70 to 90 percent effective in preventing influenza infection in healthy persons younger than 65 years of age. While the vaccine's effectiveness in preventing influenza infection decreases in older persons, it does provide substantial protection. Among elderly persons not living in nursing homes or similar chronic-care facilities, influenza vaccine is 30 to 70 percent effective in preventing hospitalization for pneumonia and influenza. For the elderly living in nursing homes or other long-term care environments, the vaccine is 80 percent effective in preventing death from infection.

Influenza vaccination rates continue to fall below the target rates set by public health authorities. In 2005, the percentage of persons vaccinated in each risk category was:

• Persons 65 years of age and older, 63 percent
• Children 6 through 23 months of age, 48 percent
• High-risk children 2 to 17, 35 percent
• High-risk adults 18 to 64, 26 percent
• Health care workers, 36 percent

Although the CDC and other infection control and major medical and nursing groups have long recommended yearly influenza vaccination for all health care workers, only 36 percent are actually immunized each year. Unvaccinated health care workers can spread the virus to patients in their care, putting them at increased risk of serious complications and even death.

Because asthma is the most common long-term illness in children, another area of concern is the more than eight million infants and children with asthma who should receive influenza vaccine each year. Nearly 70 percent of this vulnerable population does not receive an annual vaccine - this is the lowest vaccination rate for any recommended childhood vaccine in the U.S.