Oct. 11, 2024 – “I want the senior flu vaccine.”
That’s a request Steven Furr, MD, a family doctor in Jackson, Alabama, hears more and more these days from his patients who are 65 and older.
They’re talking about flu “super vaccines” – high-dose or adjuvanted influenza vaccines made to produce a stronger than usual immune response. Since 2022, the CDC has recommended that adults 65 years and older get one of three such flu vaccines instead of a standard dose.
An ever-growing body of research backs up the advice, confirming that the shots reduce both office visits and hospitalizations for the flu among the 65-plus crowd. And we’re learning more about these powerful vaccines. Here’s what to know.
The Three Available Vaccines
If you’re 65 or older, the CDC recommends you get one of these three.
- Fluzone High-Dose is the one “most of us use,” said Furr, board chair and immediate past president of the American Academy of Family Physicians. It has four times the antigens (substances that trigger an immune response) of a standard flu shot. It is approved for adults 65 and above and is also acceptable for younger people who have had a solid organ transplant and are on immunosuppressive medicine, the CDC says.
- Flublok, the recombinant flu shot, uses an egg-free technology to trigger a stronger immune response. It is approved for anyone age 18 and older but typically reserved for people ages 65 and above, Furr said.
- Fluad Trivalent is a standard-dose flu shot with an adjuvant, an ingredient added to a vaccine that helps stimulate the immune system. It is approved for adults 65 and older but is also an option for people who have had a solid organ transplant and are on immunosuppressive medicine.
Drugmakers say all are widely available this year at doctors’ offices and pharmacies. But not all locations may always have them, depending on demand and wait times for new supplies. In that case, you should consider a standard dose rather than waiting, advises the CDC.
Some side effects are reported more often with high-dose vaccines than standard-dose ones, according to the CDC – including pain, muscle aches, and soreness at the injection site – but are usually mild. Furr said most of his older patients tolerate the enhanced vaccines well.
What Recent Research Found
While the relative benefits of enhanced flu shots have been known for several years, few studies have compared the vaccines head-to-head with the standard dose – or with each other. An analysis of 32 studies and more than 71 million people, published in September and done by the CDC, did just that.
It found that the enhanced vaccines provided modestly stronger protection against flu-related hospitalization than the standard-dose vaccine for adults 65 and above. When the researchers looked at data from all three vaccines combined, the risk of flu-related hospitalization declined by 11% in the bulk of the studies. The researchers also found that none of the three vaccines performed better than the others in providing protection.
Should You Get an Enhanced Flu Shot if You’re Under 65?
Some research is finding these enhanced vaccines may help adults 50 to 64 as well. A study of 675,000 people ages 50 to 64, funded by Sanofi (one of the vaccine makers), found that one enhanced vaccine – the recombinant flu shot known as Flublok – was 15% better at preventing infection than the standard dose.
“There’s no reason to think it wouldn’t benefit them,” said Aaron Glatt, MD, chair of medicine and a hospital epidemiologist at Mount Sinai South Nassau in Oceanside, New York, who reviewed the study.
But does that mean you should get one if you’re under 65? The short answer: Probably not.
Younger age groups are at lower risk of flu-related complications to begin with, Glatt said. Up to 85% of flu-related deaths and up to 70% of flu-related hospitalizations happen in adults ages 65 and over, the CDC estimates.
Glatt doesn’t anticipate the CDC to change its recommendation based on the current evidence. “The CDC and [its] Advisory Committee on Immunization Practices (ACIP) make recommendations very slowly and carefully,” he said.
“The reason we do the high-dose for the older group is that they are more likely to have complications and be hospitalized,” Furr said, noting the higher cost of the enhanced vaccines. “Only further studies will determine whether there’s really a cost benefit.”
He said he wouldn’t consider the enhanced vaccines for those the CDC doesn’t recommend them for.
Glatt said he’d consider it case-by-case for higher-risk patients under 65, such as those with an illness or a history of severe flu.
Sanofi said that its Flublok, approved for ages 18 and up, is often given to patients ages 50 to 64 who may have a higher rate of chronic health conditions and are prone to flu complications.
