Recently, many physicians offices have been inundated with requests for the so called “high dose” flu shot. I know I’ve had many patients ask in my own office, and this is the result of all the publicity around these shots. Pharmacies were specifically advertising that they had the high dose shots available. Heck some pharmacies even offered customers points for getting your shots. Until of course, they ran out. (Memo to pharmacies – unlike Teslas, generally not a good idea to advertise something you can’t deliver on time).
Of course once they ran out came the inevitable concerns expressed about why people couldn’t get a “high dose” shot themselves. I have also heard some isolated reports in my community about people waiting to get their flu shot until the high dose were back in supply.
But here’s the thing. There is no evidence to suggest that the high dose flu shot is actually better than the current standard dose shot. Seriously.
In 2014, a study was done looking at the high dose versus regular flu shots, particularly in older patients. The study clearly showed that there was a higher immune response in older patients with the high dose shot. But from a clinical perspective, it really only made a minor (although what statisticians will call a statistically significant) difference. 1.9% of people who got the standard flu shot went on to get the flu, and 1.4% of people who got the high dose flu shot went on to get the flu, for an effective difference of 0.5%. All this hype for 0.5%??
But more importantly, that study looked at what are called trivalent flu vaccines. In essence, both the standard and the high dose vaccines in the study were good against three strains of the flu.
However, in Ontario, our standard dose flu shot is a quadrivalent. It’s good against four strains of the flu. The high dose continues to be a trivalent. So the option for people in Ontario is to get a flu shot that has a regular dose against four strains, or a high dose shot that is good against three strains only.
Importantly, there has not been a head to head study between the high dose trivalent and the standard dose quadrivalent used in Ontario. Which means no one really knows which vaccine is better.
Heck even the Public Health Ontario Fact Sheet on flu vaccines states there is “insufficient evidence” to recommend one over the other. There is some supposition about the extra B strain that is covered in the quadrivalent vaccine not being as common in those over 65, and perhaps having a lower disease burden, but it’s not really clear cut.
So what should you do?
As I mentioned in my last blog, you should wait until November to get your flu shot. It now being November – GET IT! If you are over 65 and are unable to get the high dose, don’t sweat it, just get the standard one. Because frankly the protection you get from that is still really really good (I mean why all this fuss over a measly 0.5%??). But don’t put off getting your shot now just to wait and see if more high dose vaccines are coming.
It’s time to protect yourself and your loved ones. Both flu shots are good. Get whichever one you can, and let’s help each other stay safe.