Fa Re cul vie ty w
Expanded Options for Influenza Protection A Vaccine Designed for Older Adults © Tetra Images/Getty Images
Dear Colleague: People 65 years of age and older experience flu-related morbidity and mortality in far greater numbers than do other age groups. That fact is of particular concern given that the first Baby Boomers turned 65 years of age in 2011. Traditional influenza vaccines help protect seniors against the disease and its complications, but not nearly as well as we’d like; many older adults simply don’t have as robust an immunologic response to vaccines as younger people do. In 2005, the Centers for Disease Control and Prevention and the National Institutes of Health called for better methods to protect the older population from influenza. In the 2010-2011 flu season, an influenza vaccine intended specifically for older adults became available for the first time. That vaccine—the focus of this newsletter—gives us an important new tool in the medical armamentarium aimed at influenza, and reflects the evolution in influenza vaccines away from “one size fits all” toward a more patient-specific approach. As clinicians, it’s imperative that we take seriously the very real risk that influenza poses to our patients, young and old, and make full use of the panoply of available tools to help minimize that risk. Flu will continue to exact an unacceptably high price unless we do.
Sincerely,
William Schaffner, MD FACULTY REVIEWER William Schaffner, MD Professor and Chair Department of Preventive Medicine, Vanderbilt University School of Medicine Nashville, Tennessee
E
ach year, an estimated 15 to 60 million people in the United States—some 5% to 20% of the population—become ill with influenza.1 In any given influenza season, 55,000 to 431,000 people are hospitalized as a result of the infection, and up to 49,000 people die from its complications.1-3 The burden of disease falls disproportionately on older adults: Adults ≥65 years of age represent approximately 15% of the US population but account for more than 60% of influenza-related hospitalizations and 90% of influenza-related deaths.2,3 Influenza and pneumonia, taken together, are the seventh leading cause of death in the US among older adults.4 The clinical consequences of influenza come with a high economic price. Across all ages, direct medical costs of an outbreak of seasonal influenza in the US can amount to more than $10 billion.5 Adults ≥65 years of age account for nearly two thirds of the total annual economic burden—direct and indirect costs combined—of seasonal influenza.5 Influenza vaccination rates for older adults have hovered in the 65%-70% range in recent years.2,6 Although well below the 90% Healthy People 2010 and 2020 goals for adults 65 years of age and older, those rates are nonetheless much higher than for younger age groups. Yet the majority of influenza hospitalizations and deaths still occur in the 65-plus population. Moreover, while older adults are at increased risk for influenza infection and its potentially severe complications, they exhibit a decreased immune response to traditional influenza vaccines, part of an age-related phenomenon known as immunosenescence. All of these facts and figures are of par-
ticular concern given the population surge among seniors. Between 2000 and 2030, the number of adults 65 years of age and older is expected to double, so that by 2030 approximately 1 in 5 people in the US will be in that age group.7 The growing risk when growing old
Influenza-related mortality rates increase with advancing age (Figure 1). The mortality rate for people 65-69 years of age, for example, is approximately 3 times higher than it is for adults 50-64 years of age and 60 times higher than it is for people 5-49 years of age.8 The increase in mortality rates accelerates to the end of life. The presence of a chronic medical condition significantly increases the risk of influenzarelated death in older patients. In a study conducted within a health maintenance organization during two influenza epidemics, the mortality rate from influenza and pneumonia among persons ≥65 years of age without any comorbid high-risk condition was 9 per 100,000.9 That rate was approximately 20-fold higher in patients with one high-risk condition and 90-fold higher in those with two or more such conditions. More than 90% of patients who died in this study had at least one chronic underlying condition.9 Nationwide, more than 80% of adults 65 years of age and older have at least one chronic condition, and more than 60% have two or more chronic conditions.10 The reported efficacy of traditional influenza vaccines in preventing laboratoryconfirmed influenza infection in older adults is lower than it is in younger persons.2,11 Age-related differences in the effectiveness of influenza vaccine at preventing influenza-like