What about the new quadrivalent vaccine?
While the high-dose shot seems to offer stronger protection against flu, the quadrivalent shot gives broader protection. Every year public-health authorities design the trivalent vaccine to build immunity against the three strains of flu deemed most likely to circulate that season — two strains of type A flu and one strain of type B.
The trouble is, two separate subtypes of B virus are common causes of illness, and it's not easy to predict which one will predominate in a given year. "We're wrong about half the time," says Gregory Poland, M.D., a vaccinologist who founded and leads the Vaccine Research Group at the Mayo Clinic in Rochester, Minn.
The quadrivalent shot solves that by including both common B subtypes, so its protection is broader. However, the B viruses tend to be more virulent in children, while the A strains are more likely to cause severe illness in older people. For this reason, all three experts we spoke with recommended that people 65-plus get the high-dose standard shot — with its extra dose of A-strain vaccine — rather than the quadrivalent. The high-dose also may be easier to find than the quadrivalent, which is in shorter supply.
If You're Ages 50 to 64
The choices include the regular flu shot, the new quadrivalent flu shot, the tiny-needle shot and the egg-free Flucelvax.
Should I get the quadrivalent vaccine?
For somewhat younger adults, the quadrivalent shot may be ideal in terms of protection against flu. But here as well, studies have yet to prove superior performance over regular vaccine. And because it's brand new this year, supplies are limited. Zimmerman says that if all the alternatives were offered at the same price, for people 50 to 64 he'd choose the quadrivalent vaccine. "However, I would not travel an extra 20 minutes for it," he adds.
Is the tiny-needle shot a good option?
Those wary of needles can also opt for the tiny-needle or "intradermal" shot, which deposits the medicine under the skin rather than in the muscle, as a standard shot does. It's been approved for people ages 18 to 64 and protects against three viral strains, same as the standard flu shot. It also can be harder to find than the standard flu shot.
What about the egg-free vaccine?
Anyone 18 or older who is hypersensitive to eggs — a problem that's actually far more common in young children — can choose a vaccine whose virus is grown in mammalian cells rather than chicken eggs.
Katharine Greider is a freelance writer.