The influenza-causing family of viruses has spread across the country until a recent, delayed return of influenza A caught the attention of scientists. In March – as COVID-19 restrictions were lifted and more people began to associate – HIV-positive tests began to rise in Canada. In late April, showed federal data a test rate of almost seven percent, close to the average for this time of year and largely due to the sharp increase in Quebec. This unusually delayed flu season may provide clues as to how COVID and the flu will affect each other in the coming years, with one theory suggesting that these two rival viruses could go away – but it is difficult to predict how it will just look like. “It will be interesting to see what happens as COVID becomes less dominant if the flu starts to compete with it and they have a tug of war over the next two years,” said Dr. Sumon Chakrabarti, an infectious disease specialist with Trillium Health Partners in Mississauga, Ont.

The flu usually increases in winter

In a typical flu year, cases initially increase in the fall, increase in the winter, and decrease in the spring, with sporadic infections throughout the rest of the year – with influenza A viruses circulating before influenza B. The disappearance of viruses throughout the pandemic may be associated, in part, with behavioral changes over much of the past two years, as COVID-19 has increased unpredictably from any other variant. “We have been able to successfully curb influenza with our other public measures related to COVID-19,” said Dr Danuta Skowronski, chief of epidemiology for influenza and emerging respiratory pathogens at the BC Centers for Disease Control. The lifting of restrictions, combined with increased global and domestic travel, has likely played a role in the return of the flu in recent months, said Dr. Isaac Bogoch, infectious disease specialist at the University Health Network in Toronto. An unmatched flu vaccine at this time of year may be another factor behind this unusual rise, as reported by the US public health authoritiesor just a reduction in immunity from shots fired back in the fall, according to Skowronski. However, some avid observers of COVID-19 say that the virus that causes it, SARS-CoV-2, may also have helped keep the flu away. A sign showing the estimated waiting time at Humber River Hospital is displayed in its Toronto Emergency Department on April 26. The hospital is treating a higher volume of patients and an increase in flu cases. (Alex Lupul / CBC)

“Viral intervention”

There was once speculation that COVID-19 and the flu could create what some have called “didimia”, Both types of infections affect countries at the same time, but these fears have not been realized. On the contrary, some medical experts say that there could be some level of “viral intervention” in which a virus such as COVID-19 repels other pathogens in the general population over a period of time. “There is some interesting antivirus and competition here,” said Chakrabarti, who suggested that COVID and the flu could be circulating. Throughout the pandemic, he explained, widespread COVID-19 infections may have kept the human immune system on high alert, giving SARS-CoV-2 a long-term advantage over the flu. Influenza A cases began to rise unusually in Canada later this year, following the lifting of public health restrictions and when more Canadians began socializing and traveling. (Alex Lupul / CBC)
“There have been flu cases this year, mostly in US pockets, but again it was clearly not a normal flu season and the flu was clearly suppressed,” Bogoch said. “Now, people are talking about viral influenza with the flu and COVID and I would not have known anything. I think the short answer is that you can not be overconfident about how things will go next year.” On the other hand, virologist Alyson Kelvin of the University of Saskatchewan Vaccine and Infectious Diseases Organization said the sudden return of the flu could actually be linked to the weakening of the immunity of millions of Canadians from the fifth and sixth wave of COVID-19 – not exacerbated by Covid19 Infection. “The release of SARS-CoV-2 – specifically Omicron – may have left humans slightly immunosuppressed,” he said. “Once the virus enters and infects humans, their immune systems are weaker, leaving an opportunity for influenza A to infect people in the weeks following their initial Omicron infection.” CLOCKS Canadians are urged to receive amplifiers during the 6th wave:

Canadians urged to receive boost shots for COVID-19 to mitigate 6th wave

All indications are that Canada is going through a sixth wave of pandemics, confirms Dr. Theresa Tam. Her message to Canadians: wear a mask and step up if they are eligible. 2:00 p.m.

Possible different flu pattern

Several experts who spoke to CBC News agreed that there could be unexpected changes in the flu season based on how the virus behind COVID-19 works in the future. “Will SARS-CoV-2 and COVID-19 cases become more seasonal? If so, can we see a different pattern of flu cases,” Kelvin said. In the short term – more reassuringly – both viruses are expected to disappear as the weather warms before they return, sometime in the fall. This period of calm is a time when health care systems and governments must begin to plan for an uncertain future, according to Dr. Leon Rivlin, head of emergency medicine at Humber River Hospital. Dr. Leon Rivlin, Head of Emergency Medicine at Humber River Hospital, Emergency Department in late April. It is preparing to increase the number of COVID-19 cases. (Alex Lupul / CBC)
At the moment, as flu cases are on the rise, hospitals are still experiencing staff shortages associated with COVID-19, he said. In his team, seven doctors called patients for suspected SARS-CoV-2 infections just last weekend. “We will have this upsurge again,” he warned. “Once again, we will push for human resources.” The coming months could be crucial to ensure that Canadians continue to receive vaccines that provide protection against serious illness, while policymakers ensure that there is sufficient space and staff to treat patients with severe COVID-19 or flu. “There will be both short-term and long-term solutions,” Chakrabarti said. “Ultimately, we need some way to absorb every sudden wave of infection that occurs.”