Extending the benefits of influenza vaccination

October 2006

Most physicians, and indeed most adults, are aware that influenza vaccination is recommended for everyone 65 and older. But fewer know that since the year 2000, the Centers for Disease Control and Prevention actually recommends annual vaccination for all adults aged 50 to 64, too. This lack of awareness is one reason less than 40% of adults in this age group get the influenza vaccine annually.

Influenza vaccination offers many benefits to these younger adults. It reduces influenza incidence, morbidity and mortality. Vaccination also leads to savings in both direct (eg, medical care) and indirect (eg, lost work time, increased childcare expenses) costs. And, for those aged 50 to 64, the so-called “sandwich generation,” it may reduce the risk of transmitting the virus to their young children or grandchildren and to their older parents, all of whom may be at increased risk for serious complications from influenza.

Given the CDC’s vaccination recommendations, low immunization rates and clear benefits of immunization, we must ask ourselves: Am I doing enough to increase vaccination rates to protect my patients? We must recognize the importance of our role; patients often act on our advice. Although research indicates many specialists do not administer influenza vaccine, we can take an active role by advising our patients to seek influenza vaccination, whether from their primary health care provider or an alternative vaccination setting (eg, retail stores). We can encourage our colleagues to do the same with their patients.

Vaccination and older patients

As is true for all age groups, vaccination is the optimal way to prevent influenza infection in this cohort. Efficacy against culture-confirmed influenza infection in healthy people aged 50 to 64 is 70% to 90%. Reasonable and expected uncertainties, immune status of those vaccinated and antigenic match between circulating and vaccine strains affect vaccine efficacy. When antigenic match is not perfect, however, vaccination invariably provides at least partial protection. Even in the case of less than optimal efficacy, providing some protection is better than providing none. To paraphrase Voltaire: Waiting for perfection is the greatest enemy of the current good.

Preventing infection would be the optimal goal; however, the main reason for influenza vaccination is prevention of serious complications, such as pneumonia, hospitalization and death. Vaccinated people who contract influenza generally have less severe courses than their unvaccinated counterparts. This is especially important for infants, toddlers, the elderly and those with high-risk conditions (eg, asthma, diabetes and cardiovascular disease), which describes more than one-third of people aged 50 to 64.

However the value of avoiding influenza or reducing its severity, even in those who are not at increased risk of serious complications should not be underestimated. Influenza is a severe illness characterized by an abrupt onset of high fever accompanied by myalgia, headache, malaise, non-productive cough and pharyngitis. These symptoms cause substantial morbidity for those aged 50 to 64, including increases in outpatient visits, antibiotic prescriptions and work absenteeism.

Influenza morbidity may be mitigated by antiviral medications, which, when administered within two days of symptom onset, reduce the duration of illness by one to two days. Antiviral medications are also approved for influenza prophylaxis during certain outbreak situations (eg, in institutions), and they should be considered when vaccination is not an option (eg, for patients with a hypersensitivity to egg proteins or other vaccine components).

Beyond individual protection

Although reducing personal influenza-related morbidity and lost work time alone are sufficient reasons to vaccinate those aged 50 to 64, there are additional benefits. As part of the sandwich generation, these people often have responsibilities to young children or grandchildren and also to older parents. Influenza infection can affect their ability to meet these obligations. A disruption of two to three days or more in the life of a typical 50-something can have a considerable effect on the lives of many others.

Perhaps an even more important reason to vaccinate is that influenza is easily transmitted. Infected people are contagious for at least one day before symptom onset and for several days after. The virus can make its way to infants, toddlers, young children and elderly contacts — all of whom are at increased risk for serious complications, including death, from influenza infection. No one wants to be responsible for bringing home a virus to his or her family.

The negative effect of influenza in elderly people is well acknowledged, but the negative effect on infants, toddlers and young children has become more evident in recent years. We now know that infants and toddlers are hospitalized with complications from influenza infection at rates similar to or higher than elderly people. A recent study also makes it clear that most influenza infections in hospitalized infants and toddlers are not recognized. Poehling et al. report that influenza was listed as a diagnosis in only 28% of hospitalized children younger than 5 years who later were confirmed to have laboratory-confirmed influenza infection.

What you can do

Every health care provider who treats people aged 50 to 64 should consider his or her role in increasing influenza vaccination rates. There are things we all can do. First, strongly recommend the vaccine. Whether we recognize it or not, we have substantial influence over our patients’ vaccination decisions. Even if you are not a vaccinator, your recommendation will likely persuade patients to seek vaccination.

Certain specialists are probably unlikely to provide direct vaccination services. However, their professional organizations recognize the need for annual influenza vaccination in their patients. For example, the American Diabetes Association includes annual influenza vaccine for all diabetic patients 6 months and older as part of their “Standards of Medical Care in Diabetes.” In recently published guidelines on secondary prevention, the American Heart Association and the American College of Cardiology recommend annual influenza vaccination for individuals who have chronic disorders of the cardiovascular system because they are at increased risk for complications from influenza.

Second, take advantage of the simplicity of following age-based recommendations. It is far easier to identify patients based on age rather than underlying conditions. Age-based recommendations for influenza vaccination include adults aged 50 and older and children aged 6 to 59 months. Vaccines cannot be administered to infants younger than 6 months, which is why vaccination of their close contacts is so important.

Recommendations based on underlying conditions are less straightforward than those based on age. For people aged 5 to 49 years, annual influenza vaccination is recommended if they have conditions such as chronic cardiovascular or pulmonary disorders (including asthma), chronic metabolic diseases (including diabetes), renal dysfunction, hemoglobinopathies, immunosuppression (including that caused by medications or HIV) or any condition that can compromise respiratory function or handling of respiratory secretions. In addition, children aged 6 months to 18 years on long-term aspirin therapy should be vaccinated, as should pregnant women and residents of nursing homes or other chronic care facilities, regardless of age.

The CDC’s Advisory Committee on Immunization Practices has discussed the benefits of a universal influenza vaccination recommendation. A universal vaccination strategy would likely have a great impact on the annual number of deaths, estimated at 36,000, and hospitalizations, more than 200,000, due to influenza in the United States each year.

The CDC has also called on health care providers to continue recommending and administering influenza vaccine into the late season. Vaccination efforts tend to drop off after Thanksgiving, but vaccination into December, January and even beyond can be effective. It generally takes about two weeks to develop protective immunity after vaccination and influenza activity most often peaks in the United States around February. The value of vaccination into what is erroneously thought of as late season is evident.

Finally, we must get vaccinated ourselves. Annual influenza vaccination of health care workers is important. We get all the same benefits as everyone else: reduced morbidity, mortality, fewer lost workdays and reduced risk of transmitting the virus to our friends and family.

Most importantly, we also fulfill an integral professional obligation — reducing the risk of transmitting the virus to patients in our care. Unvaccinated health care workers have been implicated as the likely source of influenza transmission during inpatient influenza outbreaks. By getting vaccinated, we reduce this risk and set a good example for our patients.

Part of the routine

Many routine patient screenings begin or continue through age 50. Annual influenza vaccination is a simple, safe and effective preventive measure that should be added to the routine. And, despite the media (and hopeful middle-agers) trumpeting “40 as the new 30” and “50 as the new 40,” the medical reality is that 50 is, well, 50 and it’s a perfect time to add influenza vaccination to our patients’ annual regimen, helping them to stay healthy and active.

For more information:

• William Schaffner, MD, is Professor and Chairman of the Department of Preventive Medicine and Professor of Medicine in the Division of Infectious Diseases at Vanderbilt University School of Medicine in Nashville, Tennessee. He also serves as Hospital Epidemiologist at Vanderbilt University Hospital and is a member of the National Foundation for Infectious Diseases’ board of directors and executive committee.
• Poehling KA, Edwards KM, Weinberg GA, et al. The underrecognized burden of influenza in young children. N Engl J Med. 2006;355:31-40.
• American Diabetes Association. Standards of medical care in diabetes – 2006. Diabetes Care. 2006;29(Suppl. 1):S4-S42.
• Smith SC Jr., Allen J, Blair SN, et al. AHA/ACC guidelines for secondary prevention for patients with coronary and other atherosclerotic vascular disease: 2006 update: endorsed by the National Heart, Lung, and Blood Institute. Circulation. 2006;113:2363-2372.