What Canada can learn from the Southern Hemisphere's season of 'virtually no influenza'
The Southern Hemisphere has been celebrating a silver lining in the dark cloud of the COVID-19 pandemic -- historically low rates of seasonal influenza, particularly in Australia.
“There is virtually no influenza here currently and hasn’t been since the end of March,” said Ian Barr, Deputy Director of the World Health Organization Collaborating Centre for Reference and Research on Influenza in Melbourne.
As an example, Barr cites the numbers from July when Australia charted 93 cases of lab-confirmed cases of influenza. “In 2019 we had 70,071 [cases] so you can see they're dramatically different,” he said.
Hospitalizations for influenza in Australia are also dramatically lower this year than the previous five years.
“We'll never see these numbers again, I don't think,” said Barr in an interview with CTV News.
South Africa, Argentina, Chile and New Zealand also noted the same surprising trend. In some cases there was a marked uptick in flu vaccinations. Australia reported a near 150 per cent increase in flu vaccine uptake, which is a record rate.
But many experts credit health measures against COVID-19 for apparently stopping the spread of flu in its tracks.
“It tells you that …. when you stop airlines, you stop the influenza coming in and if you stop people circulating and meeting each other you stop influenza spreading and it's not just influenza I should add, so it's a whole host of other respiratory diseases,” said Barr.
But influenza hasn’t disappeared altogether. A WHO report says that while "globally, influenza activity was reported at lower levels than expected for this time of year," sporadic cases are still being reported.
And as countries relax coronavirus control measures and open up travel and commerce, they become doorways for the flu virus to enter and spread to some degree.
“I think while you've got an open society and free movement between borders, then you're quite susceptible to having a major influence around outbreak along with COVID, said Barr.
The advice from the Southern Hemisphere? “Be prepared -- you know there's not a lot you can do once you have influenza circulating at higher levels … all you really do is prepare for it,” Barr said. “And vaccine is the best measures we have against influenza so you know it's a relatively cheap method.”
The Southern Hemisphere’s unusually mild flu season brings a new challenge – there were so few cases it may be difficult, if not impossible, to find a vaccine match for next season since there were so few sample of the flu virus taken.
The meeting to discuss the composition of the next flu vaccine is set for Sept. 16. Barr calls it unsettling because COVID-19 has now changed the normal ebb and flow of flu vaccine design and production.
“It's going to be a difficult task,” he said of the efforts to decide how the next flu vaccine should be prepared.