An unnerving flu season in the Southern Hemisphere bodes poorly for those in the north.
Sometime in the spring of 2020, after centuries, perhaps millennia, of tumultuous coexistence with humans, influenza abruptly went dark. Around the globe, documented cases of the viral infection completely cratered as the world tried to counteract SARS-CoV-2. This time last year, American experts began to fret that the flu’s unprecedented sabbatical was too bizarre to last: Perhaps the group of viruses that cause the disease would be poised for an epic comeback, slamming us with “a little more punch” than usual, Richard Webby, an influenza expert at St. Jude Children’s Research Hospital, in Tennessee, told me at the time.
But those fears did not not come to pass. Flu’s winter 2021 season in the Southern Hemisphere was once again eerily silent; in the north, cases sneaked up in December—only to peter out before a lackluster reprise in the spring.
Now, as the weather once again chills in this hemisphere and the winter holidays loom, experts are nervously looking ahead. After skipping two seasons in the Southern Hemisphere, flu spent 2022 hopping across the planet’s lower half with more fervor than it’s had since the COVID crisis began. And of the three years of the pandemic that have played out so far, this one is previewing the strongest signs yet of a rough flu season ahead.
It’s still very possible that the flu will fizzle into mildness for the third year in a row, making experts’ gloomier suspicions welcomingly wrong. Then again, this year is, virologically, nothing like the last. Australia recently wrapped an unusually early and “very significant” season with flu viruses, says Kanta Subbarao, the director of the WHO Collaborating Centre for Reference and Research on Influenza at the Doherty Institute. By sheer confirmed case counts, this season was one of the country’s worst in several years. In South Africa, “it’s been a very typical flu season” by pre-pandemic standards, which is still enough to be of note, according to Cheryl Cohen, a co-head of the country’s Centre for Respiratory Disease and Meningitis at the National Institute for Communicable Diseases. After a long, long hiatus, Subbarao told me, flu in the Southern Hemisphere “is certainly back.”
That does not bode terribly well for those of us up north. The same viruses that seed outbreaks in the south tend to be the ones that sprout epidemics here as the seasons do their annual flip. “I take the south as an indicator,” says Seema Lakdawala, a flu-transmission expert at Emory University. And should flu return here, too, with a vengeance, it will collide with a population that hasn’t seen its likes in years, and is already trying to marshal responses to several dangerous pathogens at once.
The worst-case scenario won’t necessarily pan out. What goes on below the equator is never a perfect predictor for what will occur above it: Even during peacetime, “we’re pretty bad in terms of predicting what a flu season is going to look like,” Webby, of St. Jude, told me. COVID, and the world’s responses to it, have put experts’ few forecasting tools further on the fritz. But the south’s experiences can still be telling. In South Africa and Australia, for instance, many COVID-mitigation measures, such as universal masking recommendations and post-travel quarantines, lifted as winter arrived, allowing a glut of respiratory viruses to percolate through the population. The flu flood also began after two essentially flu-less years—which is a good thing at face value, but also represents many months of missed opportunities to refresh people’s anti-flu defenses, leaving them more vulnerable at the season’s start.
Some of the same factors are working against those of us north of the equator, perhaps to an even greater degree. Here, too, the population is starting at a lower defensive baseline against flu—especially young children, many of whom have never tussled with the viruses. It’s “very, very likely” that kids may end up disproportionately hit, Webby said, as they appear to have been in Australia—though Subbarao notes that this trend may have been driven by more cautious behaviors among older populations, skewing illness younger.
Interest in inoculations has also dropped during the pandemic: After more than a year of calls for booster after booster, “people have a lot of fatigue,” says Helen Chu, a physician and flu expert at the University of Washington, and that exhaustion may be driving already low interest in flu shots even further down. (During good years, flu-shot uptake in the U.S. peaks around 50 percent.) And the few protections against viruses that were still in place last winter have now almost entirely vanished. In particular, schools—a fixture of flu transmission—have loosened up enormously since last year. There’s also just “much more flu around,” all over the global map, Webby said. With international travel back in full swing, the viruses will get that many more chances to hopscotch across borders and ignite an outbreak. And should such an epidemic emerge, with its health infrastructure already under strain from simultaneous outbreaks of COVID, monkeypox, and polio, America may not handle another addition well. “Overall,” Chu told me, “we are not well prepared.”
www.theatlantic.com
Sometime in the spring of 2020, after centuries, perhaps millennia, of tumultuous coexistence with humans, influenza abruptly went dark. Around the globe, documented cases of the viral infection completely cratered as the world tried to counteract SARS-CoV-2. This time last year, American experts began to fret that the flu’s unprecedented sabbatical was too bizarre to last: Perhaps the group of viruses that cause the disease would be poised for an epic comeback, slamming us with “a little more punch” than usual, Richard Webby, an influenza expert at St. Jude Children’s Research Hospital, in Tennessee, told me at the time.
But those fears did not not come to pass. Flu’s winter 2021 season in the Southern Hemisphere was once again eerily silent; in the north, cases sneaked up in December—only to peter out before a lackluster reprise in the spring.
Now, as the weather once again chills in this hemisphere and the winter holidays loom, experts are nervously looking ahead. After skipping two seasons in the Southern Hemisphere, flu spent 2022 hopping across the planet’s lower half with more fervor than it’s had since the COVID crisis began. And of the three years of the pandemic that have played out so far, this one is previewing the strongest signs yet of a rough flu season ahead.
It’s still very possible that the flu will fizzle into mildness for the third year in a row, making experts’ gloomier suspicions welcomingly wrong. Then again, this year is, virologically, nothing like the last. Australia recently wrapped an unusually early and “very significant” season with flu viruses, says Kanta Subbarao, the director of the WHO Collaborating Centre for Reference and Research on Influenza at the Doherty Institute. By sheer confirmed case counts, this season was one of the country’s worst in several years. In South Africa, “it’s been a very typical flu season” by pre-pandemic standards, which is still enough to be of note, according to Cheryl Cohen, a co-head of the country’s Centre for Respiratory Disease and Meningitis at the National Institute for Communicable Diseases. After a long, long hiatus, Subbarao told me, flu in the Southern Hemisphere “is certainly back.”
That does not bode terribly well for those of us up north. The same viruses that seed outbreaks in the south tend to be the ones that sprout epidemics here as the seasons do their annual flip. “I take the south as an indicator,” says Seema Lakdawala, a flu-transmission expert at Emory University. And should flu return here, too, with a vengeance, it will collide with a population that hasn’t seen its likes in years, and is already trying to marshal responses to several dangerous pathogens at once.
The worst-case scenario won’t necessarily pan out. What goes on below the equator is never a perfect predictor for what will occur above it: Even during peacetime, “we’re pretty bad in terms of predicting what a flu season is going to look like,” Webby, of St. Jude, told me. COVID, and the world’s responses to it, have put experts’ few forecasting tools further on the fritz. But the south’s experiences can still be telling. In South Africa and Australia, for instance, many COVID-mitigation measures, such as universal masking recommendations and post-travel quarantines, lifted as winter arrived, allowing a glut of respiratory viruses to percolate through the population. The flu flood also began after two essentially flu-less years—which is a good thing at face value, but also represents many months of missed opportunities to refresh people’s anti-flu defenses, leaving them more vulnerable at the season’s start.
Some of the same factors are working against those of us north of the equator, perhaps to an even greater degree. Here, too, the population is starting at a lower defensive baseline against flu—especially young children, many of whom have never tussled with the viruses. It’s “very, very likely” that kids may end up disproportionately hit, Webby said, as they appear to have been in Australia—though Subbarao notes that this trend may have been driven by more cautious behaviors among older populations, skewing illness younger.
Interest in inoculations has also dropped during the pandemic: After more than a year of calls for booster after booster, “people have a lot of fatigue,” says Helen Chu, a physician and flu expert at the University of Washington, and that exhaustion may be driving already low interest in flu shots even further down. (During good years, flu-shot uptake in the U.S. peaks around 50 percent.) And the few protections against viruses that were still in place last winter have now almost entirely vanished. In particular, schools—a fixture of flu transmission—have loosened up enormously since last year. There’s also just “much more flu around,” all over the global map, Webby said. With international travel back in full swing, the viruses will get that many more chances to hopscotch across borders and ignite an outbreak. And should such an epidemic emerge, with its health infrastructure already under strain from simultaneous outbreaks of COVID, monkeypox, and polio, America may not handle another addition well. “Overall,” Chu told me, “we are not well prepared.”
The Strongest Signal That Americans Should Worry About Flu This Winter
An unnerving flu season in the Southern Hemisphere bodes poorly for those in the north.
www.theatlantic.com
