To get or not to get the flu shot — that is the annual question. This year we asked Dr. Robin Williams, Ontario’s Associate Chief Medical Officer of Health, to address many common questions and concerns.
How is the flu shot different every year?
“The virus is very smart, it migrates and shifts and changes,” said Dr. Williams. “Sometimes it does a big shift, sometimes it just does a little shift. The world experts gather at the World Health Organization in Geneva every year and look at what they’ve isolated in the previous season, both in the Northern and Southern hemisphere, to try to determine what the best match of the subsets of the virus and the bugs are, and what’s the best match to put in the vaccine.”
This year, researchers have landed on three components, making it a trivalent vaccine. At its best, this year’s vaccine is 90 percent efficient. According to Dr. Williams, it’s usually somewhere between 70 and 90 percent. “You don’t know until you start to see what bug it is we get, and have we got a good match.” But even if it’s “only 70 percent effective,” Dr. Williams says, this protection is much better than nothing. And she adds that the percentage only represents its protective efficacy, and has nothing to do with risk.
Who should get the flu shot? Who shouldn’t?
Infants over six months old can start getting the flu shot, says Dr. Williams, adding that they need two doses if it’s their first time getting vaccinated. The same applies to anyone who hasn’t had a shot since July 2010. This is the H1N1 (swine flu)-containing vaccine. After that, it’s just a single dose. Pregnant women should also get the flu shot. The only people who should not get the flu shot are infants under six months old, anyone with an anaphylaxis allergy to any of the ingredients in the vaccine, or anyone who has developed the rare one-in-a-million Guillain-Barré Syndrome (GBS) within six weeks of a previous influenza immunization should avoid influenza immunization in the future.
Hold off on the flu shot if you have a moderate to severe illness with fever, wait until your symptoms subside. People with a cold, but no fever, can get the flu shot. If you have a neurological disorder that is developing, hold off until the disease is stable.
Does the flu shot give me the flu?
“I can say with factual clarity that you do not get influenza from this vaccine, it does not give you influenza,” said Dr. Williams.
There are many factors for why people have personal anecdotes about feeling sick after getting the flu shot. “You might have been incubating influenza before we gave you the shot, that’s not to say it didn’t fully protect you – although we do know that if you get influenza in the environment you’re in after you’ve had the shot, it’s more likely not to be as serious an illness.”
Dr. Williams says some people might mistake their illness for the flu. “There’s a whole variety of other viruses that we follow every morning on rounds, coronavirus, rhinovirus, others that can give you illness, and it wouldn’t have been the influenza.”
How do you address concerns about formaldehyde, aluminum, mercury, Alzheimer’s?
Some components of a vaccine have raised concerns because it is perceived as dangerous; however, these ingredients or preservatives are tested and known to be harmless and already naturally found in our bodies or in nature. The mercury found in vaccines, for example, is not the poisonous methylmercury many mistake it for, but the natural ethylmercury, called thimerosal, which is an additive and keeps vaccines safe and clean, preventing any bacteria or fungi growth. The mercury used in vaccines is harmless and not worth any concern, according to Dr. Williams.
That said, even thimerosal has been removed from some vaccines. “Thimerosal has been removed not because of science, but because of perception,” says Dr. Williams. “It’s an ethylmercury, not the methylmercury, which is the one that has been associated with Minamata disease and Alzheimer’s.
“It’s been removed where it could be removed, since it keeps the vaccines safe from being contaminated. The multi-dose flu vaccine does contain thimerosal. If people feel strongly, though, there’s a vaccine available, it’s a single dose, without thimerosal. But I want to clarify that this kind of mercury that’s in it, keeps vaccines clean and sterile and allows it to be stored. The ethylmercury is removed very quickly from the body, so I’m not concerned about thimerosal. It has been removed because of perception. We want to go with what parents are comfortable. It’s absolutely safe.”
Formaldehyde, another concern to some patients, is found not only in the flu vaccine but also the diphtheria, tetanus, and polio vaccines. It inactivates the toxins from the weakened virus in vaccines. Commonly associated with preserving dead bodies, formaldehyde has a scary reputation, but we are constantly exposed to it, says Dr. Williams. Formaldehyde is made inside our own bodies, as part of single carbon metabolism; it’s used to make DNA and the building blocks of amino acids. There is a quantity of formaldehyde in our bodies much greater than any small amount found in vaccines, so it is also not a concern.
According to Dr. Williams, aluminum, another additive, has also caused unnecessary concern. As aluminum is found in much larger quantities in baby formula, flour, dairy products, and our daily ingestion than in a vaccine, it is nowhere near being dangerous as well.
Isn’t it better to boost your immunity naturally?
Many believe that whatever is natural is better for you, and that “naturally” building your immune system with vitamins is preferable to a vaccine. But Dr. Williams says there is no better or alternative way to fight the flu than the vaccine.
“I do think a healthy lifestyle is important: physical fitness, washing your hands, a healthy diet, and appropriate vitamins,” said Dr. Williams. “You stay within the speed limit, wear your seatbelt, don’t drink and drive, those are all healthy things all of us should do, and I believe getting vaccines is part of that.”
Flu season generally lasts from November to April, but flu shots are available now as it takes a while for your body to build its immunity.