When was the last time you got sick? If you’ve avoided the ‘rona, it’s probably been a while since you caught any minor illnesses.
That’s because, in our bid to eliminate COVID, we’ve also managed to largely wipe out many other infectious diseases. Mask wearing, social distancing and hand washing all work great to stem the spread of COVID-19, but they also work on pretty much everything else.
In 2019, Australia experienced one of the worst flu seasons on record, with 313,085 cases recorded in that year, resulting in the deaths of 953 people. In 2021, we’ve had just 436 cases so far and not a single person has died.
In August, typically one of the worst months for the flu, 2019 saw nearly 61,000 cases. This year? Just one case of the flu across the entire country.
While this is certainly a cause for celebration, experts are warning that the flu could return once international travel resumes and we don’t know how bad it could be. Medical professionals across the globe are gearing up for a serious flu season, particularly in places like the US, where much of the population has had COVID and could be recovering with a weakened immune system.
What Happened to the Flu?
Speaking to the ABC, the deputy director of the WHO Collaborating Centre for Reference and Research on Influenza, Professor Ian Barr said that the measures introduced to fight the COVID-19 pandemic have worked to wipe out the flu as well.
“As soon as COVID restrictions were enforced, and international borders were closed … last year, we saw a dramatic tail-off in influenza cases,” he said.
The closures of schools and workplaces, which are normally key areas for the spread of that virus, have also hugely contributed to limiting its reach. Not to mention the complete lack of travel both domestically and internationally.
“All those measures have contributed to the lack of influenza circulating over the last two years,” he said.
The flu is typically seasonal, thriving in colder weather when our immune systems are a little more rundown. Because of the wonders of international travel, infected travellers carry the virus across the globe, allowing it to circulate and mutate during the winter months before it heads back across the globe for the following season.
This is why we get flu shots every year as, like COVID-19, the virus changes over time and becomes more effective at navigating our immune responses.
However, not all viruses have been hit quite as badly as influenza. Rhinoviruses — those that cause the common cold — are still around as well as respiratory syncytial virus that infects the respiratory system.
The survival of these viruses and not the flu could be down to the fact that these are tougher, more resilient viruses whereas the flu is more susceptible to being broken down in the body.
What Happens When the Flu Comes Back
With the return of international travel and the relaxing of COVID restrictions, it’s undoubtable that the flu will also be reappearing.
What is concerning to doctors is the fact that hardly anyone has caught the disease this year, meaning that there is very little immunity towards the more advanced and developed flu strains that we’ve yet to get.
Speaking to the Royal Australian College of General Practitioners, Professor Barr has said that “Things will start to happen pretty quickly as borders are relaxed”.
“It will take a while for the numbers to build up to feed into the surveillance systems. I would think within 12–18 months we’ll have a good idea of where the human seasonal influenza viruses are hitting.”
The lack of flu vaccinations too in Australia is likely to have a big impact on our immunity towards the disease which could again lead to a larger outbreak when it does return.
Interestingly, Novavax is already trialling combined COVID-19 and flu jabs in one so that if, as it has been suggested, the coronavirus does become a seasonal concern like the flu, we can be more efficiently protected against both in the future.