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July 22, 2019

Australia’s flu: What’s it have to do with you?

Dr. Jeff PernicaDr. Jeff Pernica is an infectious disease specialist at Hamilton Health Sciences.

There’s a lot of attention in the news right now about the flu season in Australia. Some are calling it the worst in years. Although this sounds scary, it’s important to understand what we can learn from Australia’s flu, and how we can use this information to protect ourselves in Canada.

Influenza is an interesting infection – only the same few strains of flu circulate all over the world. So, when Australia’s flu season begins in June, we pay close attention over here in North America. (Because Australia is located in the southern hemisphere, its winter begins in June.) As flu causes illness in the south, scientists can study those viruses and make predictions about how the flu will impact those of us in the north.

The types of flu strains circulating most widely in Australia right now are likely to be very similar to the ones that will appear in Canada in the fall. These insights help us make decisions about how to formulate our influenza vaccine for the fall so that it can be as effective as possible. And while predictions are never perfect, they’re often accurate.

How effective is the flu vaccine?

You might ask: if we have all this information, why isn’t the vaccine 100 per cent effective? And that’s a very good question. Last year, scientists’ predictions about what specific influenza viruses would be circulating were quite accurate, and so vaccine effectiveness was very good (at 72%) – but even so, science has not yet been able to design a vaccine that can guarantee immunity from infection.

What’s more is that, some years, the type of influenza virus that arrives in the fall in Canada is different than what scientists predict. When this happens, vaccine effectiveness is even lower. Educated guesses are made based on global trends and scientific knowledge, but sometimes nature surprises us. A new strain of flu might crop up unexpectedly, or the patterns change between seasons. In an ideal world we wouldn’t have to guess at all, but generally speaking the science of flu prediction is well-advanced.

So, should we be worried about our flu fate for this year in Canada? It’s true that, in Australia, influenza season has arrived early and that numbers are higher than expected. However, at the same time, these influenza viruses do not appear to be causing more severe disease than normal. As an expert in infectious disease, my advice is the same as any other year: you can significantly lower your risk of getting the flu by getting your flu shot.

For the average healthy adult, the likelihood of the flu causing complications is very low. But, in Canada, every year, influenza causes more than 12,000 hospitalizations and 3,500 deaths. Many of those people are young, old, or immunocompromised, meaning their body can’t fight off infections as well as others. By getting vaccinated, we are helping to prevent serious illness and even death from the flu.

Flu myths put us at risk

There are many myths surrounding the flu shot. Unfortunately, myths cause people to avoid getting their flu shot which, in turn, puts others at risk. If you have questions about the flu vaccine, speak with your family doctor who can provide balanced, evidence-based information.

Like all medicine, the flu shot isn’t perfect but it’s the best tool we have available to us. Combined with regular hand-washing and other healthy habits, it’s your best line of defense against the flu this fall.

To stay up-to-date on flu shot availability and clinics in Hamilton, visit the City of Hamilton’s website.