Alberta seniors will have to wait until December if they want high-dose flu shot

A flu vaccine that may offer more protection for seniors will likely not be available in Alberta pharmacies until December.

The regular flu shot is free for all Albertans above six-months-old and already available at many pharmacies, doctors offices and clinics.

But while the Fluzone High-Dose vaccine is covered for all seniors or all long-term care home residents in six provinces and territories, Alberta seniors who prefer the high-dose to the regular vaccine will have to pay $75 out of pocket.

Our messaging to seniors is to take advantage of the opportunities around them to get the vaccine that's available free of charge.- Dr. Deena Hinshaw, Alberta Health

The high-dose vaccine offers four times the amount of antigen — the part of the vaccine that stimulates the body's immune response — than the free vaccine.

But the high-dose shot only contains three strains of the virus, while the regular flu shot protects against four.

"There's a bit of a trade off there when you're making a population coverage decision. So again we've chosen to go with the vaccine that provides the protection against the most strains," said Dr. Deena Hinshaw with Alberta Health.

Hinshaw said there is evidence the high-dose vaccine has benefits for individuals.

The high-dose vaccine was found to be 24 per cent more effective than the standard-dose vaccine for seniors in a 2014 study from the New England Journal of Medicine. However, that study only looked at a single season — so available research hasn't assessed its effectiveness over longer periods with multiple circulating viruses.

Seniors more vulnerable

Adults over 65 are more vulnerable to the flu because of weaker immune systems and because they're more likely to have other compounding medical conditions.

"The protection you get from a vaccine is really dependent on how strong your immune response is. So if a standard vaccine isn't activating enough of your immune system the patient may not have the same level of protection," said Dr. Craig Jenne, who researches infectious diseases at the University of Calgary.

Canada's influenza vaccination rate for seniors is lower than other developed countries like New Zealand, the U.S. and South Korea.

Alongside vaccines that are targeted to seniors, another way to increase protection is herd immunity — ensuring people who interact with seniors or other vulnerable groups are vaccinated, according to Canada's National Institute for Aging.

Sanofi Pasteur, which manufactures the high-dose shot, says it's prioritizing deliveries to provinces that have provincial coverage. Shipments to Alberta will be sent in late November and early December in time for peak flu season from December to February, a company spokesperson said in an email.

Hinshaw says the most important thing is to get vaccinated, no matter which vaccine someone chooses.

"Our messaging to seniors is to take advantage of the opportunities around them to get the vaccine that's available free of charge," Hinshaw said.