En español | Earlier than ever this year, pharmacies, doctor's offices and local health departments are rolling out the annual vaccine against that age-old but unpredictable scourge, influenza.
And this season, for the first time, many are offering a form of that shot specially designed to give people age 65 and older enhanced protection. Approved by the Food and Drug Administration late last year, the new, more expensive flu vaccine is covered by Medicare Part B.
Flu shots work by stimulating the body's immune response, and that response is typically much weaker in older folks — the very people who need protection the most. The new shot, Fluzone High-Dose, contains four times the amount of dead virus as the regular flu vaccine.
In a 2009 study of 3,876 people 65 and older, the new vaccine triggered up to an 80 percent stronger antibody response than the regular flu vaccine.
It is hoped — though not yet proven — that this apparent boost in immunity will lead to fewer or less serious cases of influenza in older people. So far, the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices has declined to recommend for or against the use of the new vaccine in place of the regular flu shot, citing a lack of evidence that the antibody boost it triggers results in more protection. A clinical trial, scheduled to be completed in 2012, is now under way to study that question.
Older men and women have always been a focus of flu vaccination campaigns because they're much more likely to suffer potentially deadly complications from influenza, such as pneumonia. Some nine out of 10 influenza deaths occur among people older than 65. And while those adults make up 15 percent of the population, they account for 65 percent of all hospitalizations and 90 percent of all deaths attributed to flu.
In general, the flu vaccine is not as effective in older people because of their reduced immune response to the shot, says Sean X. Leng, M.D., a geriatrician at Johns Hopkins University School of Medicine who studies flu immunization in older people.
In healthy adults younger than age 65, says Leng, some 70 to 90 percent mount an adequate antibody response to the flu vaccine; that's compared with about 20 to 50 percent of older adults. Preliminary results of Leng's work with the frail elderly indicate that fewer than 20 percent produce an effective immune reaction to the shot.
Wider recognition of these facts has created increasing controversy over the last few years about whether vaccination works to safeguard older people against flu. Even so, most experts continue to recommend those 65 and older get a flu shot.
Leng concurs, citing a few reasons:
- Antibody development may not be the only pathway for immune response, so that measure may not capture all the benefits older people receive from the vaccine.
- Even if a small percentage of people over 65 mount adequate immune reactions, that could have a relatively large real-world impact, since older people are so at risk from influenza.
Leng recommends the high-dose flu shot for his older patients as one way to increase protection. Researchers found that the shot was as safe as other flu vaccines but did, as expected, produce more of the typically mild side effects associated with flu shots, including redness and swelling at the injection site, as well as headache, muscle aches and fever.
The Fluzone High-Dose shot provides protection against the same three virus strains as this year's regular seasonal flu shot.
For those under age 65
Indeed, for everyone else that regular flu shot is the ticket to protection. And just about everybody over 6 months old should get it, according to new CDC guidelines. Vaccine makers expect to produce as many as 165 million doses of that regular seasonal shot — a record number. Some 67 million doses already had shipped by mid-September, well before the flu season typically gets into full swing in late autumn.
For the first time this year, all 50 states allow pharmacists to give the flu shot, which should accelerate a trend toward Americans rolling up their sleeves at the local drugstore.