10 flu shot myths demystified

Flu season is almost upon us, and St. Michael’s, Providence and St. Joseph’s are once again waging a campaign to protect patients, staff and the public from this serious infectious disease through vaccination. 

Unfortunately, we are also once again facing resistance from people who are reluctant to get the flu shot. So we asked Dr. Matthew Muller, medical director of Infection Prevention and Control at St. Michael’s, and Dr. Mark Downing, infection control officer at St. Joseph’s, to set the record straight.

Myth No.1: “I’m healthy, so I won’t get the flu. But even if I do, it’s not a serious illness.”

Dr. Muller: “Flu is not something you want to get: you could have a fever for four days, fatigue for a month and a cough even longer. In rare cases, the severe complications of flu that affect those at highest risk, such as the elderly, can result in hospitalization and death – even for young people. Also, flu can have a huge impact on those around you. In at-risk people, it can cause pneumonia, respiratory failure and death. It also can cause other illnesses. If you have underlying heart disease, it can trigger a heart attack, and if you have lung disease, it can exacerbate asthma or COPD. Healthy people can protect those around them by getting the flu shot.”

Myth No.2: “The vaccine has serious side effects.”

Dr. Downing: “Sometimes there’s a small amount of pain and a mild fever. That’s the immune system reacting to the vaccine. The only serious documented side effect is an allergic reaction if you’re hypersensitive to components in the vaccine, but this is extremely rare. Also, there is Guillain-Barré syndrome, which is when your nerves become inflamed in reaction to some sort of trigger. But the risk of that is low, around one in a million. You’re more likely to get it from the flu itself.”

Myth No.3: “You can get sick after the shot anyway – sometimes the shot gives you the flu.”

Dr. Muller: “There’s more than one virus circulating in the winter. So it could be that the vaccine protected you from flu, often the more serious infection, but you ended up getting rhinovirus or something else. Also, most people get vaccinated when they hear that flu season has arrived or start seeing people around them getting sick. The problem is that it takes two weeks for the flu shot to be effective and you might already have been exposed. And the idea that the flu shot causes the flu is completely false. We use an inactivated virus in the vaccine, so it cannot cause the flu.”

Myth No.4: “It’s just guesswork predicting the strain of the virus so I’m worried I won’t really be protected.”

Dr. Downing: “It takes some time to develop the vaccines every year, as they have to predict what strains will be circulating. Typically, what goes into a vaccine are three or four different strains, meaning either a trivalent or quadrivalent vaccine. There are usually two strains of influenza A (H1N1 and H3N2) and one or two strains of influenza B. I just read the Public Health communication saying that this year we’re probably all going to get a quadrivalent vaccine, which will give us added protection. “ 

Myth No.5: “It’s not worth getting vaccinated if I’m not fully protected”

Dr. Downing: “One of the strongest arguments for getting the flu shot is that it also impacts the severity of the illness. So even if you do get influenza, there’s good evidence that you won’t get as sick if you’ve had the flu shot, and fewer patients end up in the intensive care unit. Also, you may not transmit it as easily, so you could be protecting your colleagues and your family.”

Myth No.6: “The flu is just a 24-hour stomach bug.”

Dr. Muller: “That’s not influenza. There is a group of respiratory viruses, of which influenza is one, and a group of bacteria and viruses that can cause gastroenteritis, and Norwalk virus is one. Norwalk commonly gets labelled as the ‘stomach flu’ where you vomit for 24 hours. It also tends to hit in the winter, but it has nothing to do with the flu.”

Myth No.7: “I’m pregnant and I won’t take the shot in case I harm my baby.”

Dr. Downing: “The flu shot is recommended during pregnancy. Babies under six months old are kind of coasting on their mother’s immunity, so there’s a good reason to get the flu shot if you’re pregnant — to protect your baby when it’s born. Newborns are one of the highest-risk groups for complications from influenza.”

Myth No.8: “Isn’t it just old people who are at risk?”

Dr. Muller: “The high-risk groups for complications from influenza include babies, the elderly, pregnant women, those with compromised immune systems, those with cardiac, respiratory or neurologic conditions, Indigenous individuals and people who are overweight.”

Myth No.9: “The vaccine doesn’t always work, so why bother?”

Dr. Downing: “The important things are that you’re protecting yourself, and that you’re also protecting everyone around you. Influenza may not be a serious disease for you, but if you pass it on to your grandfather or your newborn child, it could be serious for them. And if you have to take time off work, that impacts your colleagues too. We all have a responsibility to protect those around us the best we can.”

Myth No.10: “It’s complicated to get: I don’t know where to go, when it will be available or how much it will cost.”

Dr. Muller: “Public health is saying the vaccine should be widely available on Oct. 22, but hospitals may get it a week or two earlier. It is free and you can get it from your family doctor or at most pharmacies.” (That includes the St. Joseph’s and Providence pharmacies.)