A super-vaccine for the flu is being marketed to people 65 and older

Flu season is upon us, and the demographic most vulnerable to the disease is people 65 and older.

According to the Centers for Disease Control and Prevention, about 70%-80% of seasonal flu-related deaths occur in this age group. 

 The regular flu vaccine just won't cut it, some doctors say.

James Steckelberg of the Mayo Clinic said people 65 and over should be administered high-dose vaccines to stimulate their immune system. 

The U.S. Food and Drug Administration has licensed two high-dose vaccines to people 65 and older: Fluzone High-Dose and FLUAD.

What are Fluzone High-Dose and FLUAD? 

Dr. William Schaffner, an infectious diseases specialist at Vanderbilt University Medical Center, said that although the two vaccines have the same outcome, they work a little differently.

Fluzone High-Dose contains four times the antigen that's in a standard dose, effectively making it a stronger version of the regular flu shot. FLUAD pairs the regular vaccine with an adjuvant, an immune stimulant, to cause the immune system to have a higher response to the vaccine. 

“The data indicates that no matter what flu strain is out there, it provides more protection for older people,” Schaffner said.

What's the research behind these shots? Do they work?

Research indicates that high-dose flu vaccines, such as Fluzone High-Dose and FLUAD, have improved a patient's protection against the flu. 

A peer-reviewed study published in The New England Journal of Medicine and sponsored by Sanofi, the company behind Fluzone High-Dose, found that the high-dose vaccine is about 24% more effective than the standard shot in preventing the flu.

An observational study in 2013 found that FLUAD is 51% effective in preventing flu-related hospitalizations for patients 65 and older. 

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Kristin Englund, an infectious disease physician at the Cleveland Clinic, noted that some hospitals might carry only Fluzone High-Dose because there are more studies on it and it's been on the market longer than FLUAD. 

There are no studies that do a comparative analysis between the two vaccines. There also aren't any studies that test the high-dose vaccine on younger patients, which is why the FDA licensed the vaccines only for people 65 and older. 

Will these super-vaccines cost more money?

Schaffner said that because both vaccines are more elaborate than the normal dose, they cost more to make. 

Both Fluzone High-Dose and FLUAD are covered by those who qualify for Medicare with no out-of-pocket cost. 

What flu shot to take?

The Advisory Committee on Immunization Practices at the CDC does not recommend one vaccine over the other. 

Englund said the high-dose vaccines are preferable for patients 65 and older, but they should get the regular dose if a high-dose is unavailable. 

"If the option is to get the standard dose or nothing," Englund said. "We absolutely prefer the standard dose vaccine."

How effective is it?:Here's what doctors say about the flu shot

Fluzone High-Dose and FLUAD, like many other vaccines, are egg-based. Patients with severe egg allergies shouldn't get the shot.

It's not recommended for people who have a rare disorder called Guillain-Barré syndrome, in which the body's immune system attacks the nerves. 

Side effects for the high-dose vaccines mirror the standard dose: soreness around the injection site and a low, 24-hour fever. 

Schaffner said this shouldn’t deter patients as the alternative can be fatal.

“A sore arm and one day of fever is a small price to pay to get prevention against influenza, which can be a very deadly infection,” he said.

Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT