But when forecasters try to get an idea of what the flu could hold for North America in any given winter, they look to countries like Australia and New Zealand, where the season generally runs from April to October – the winter months in the Southern Hemisphere. .
This year Australia had its worst flu season in five years. Cases peaked about three times higher than average for that period, and they peaked about two months earlier than they normally do, according to official government surveillance reports.
Flu-like illness rates have also been higher in New Zealand this year than they have been for the past two years.
The United States should take this into account, Dr. Anthony Fauci, director of the National Institutes of Allergy and Infectious Diseases, told Bloomberg News.
“The southern hemisphere had a pretty bad flu season, and it came early,” Fauci said. “The flu – as we’ve all experienced for many years – can be a serious illness, especially when you have a bad season.”
He said that means the United States could see the flu make a comeback while Covid-19 is still circulating at higher levels.
Recent government modeling predicts Covid-19 will peak again in early December.
If that happens, it would be the first winter the United States has had to deal with these two respiratory viruses circulating together at high levels, something infectious disease experts have warned about since the start of the pandemic. pandemic.
Low immunity and children without a mask
When Americans began self-isolating, social distancing and masking to slow Covid in early 2020, the flu all but disappeared.
While people have returned to their normal habits, the flu has receded, but cases have not approached pre-pandemic levels, which means most of us have not been exposed to the flu for a few years, said Dr. Jennifer Nayak, a pediatric infectious disease specialist at the University of Rochester Medical Center.
“With these few consecutive mild flu seasons, I think population immunity is probably lower than it comes into an average flu season,” Nayak said.
In addition to this, most children no longer wear masks in schools.
“We know that children are a major source of influenza infections. They catch it at school or day, and they bring it home,” says Nayak. Many adults also don’t wear masks or avoid crowded spaces, “so there’s potential for increased flu transmission” this year.
All of this underscores the need for Americans to get vaccinated. But usually about half don’t. According to the US Centers for Disease Control and Prevention, only 45% of Americans got their flu shot last season. Flu vaccination rates have plummeted for several people at risk groups, including pregnant women and children.
The US government will launch a campaign this fall to urge people to get their flu shots and update Covid-19 reminders at the same time.
Nayak wonders how these public health messages — urging people to get more vaccines to avoid more infections — might sound to pandemic-weary Americans.
“I think we still have to see how that plays out with what our flu vaccination rates are going to do,” she said.
The burden of influenza on society
All of this is still hypothetical. We won’t really know for about eight weeks what winter has in store for us.
“I think we have to keep an eye – if we’re going to have something analogous to Australia – on what’s happening in November,” said Jeffrey Shaman, modeling expert at the Mailman School of Public Health in Australia. ‘Columbia University. “Are we starting to see the flu a little earlier than usual? And it can take off. And of course, on top of that, we have to worry about how this compiles with the circulation of Covid.
Two co-circulating respiratory viruses could cause problems for hospitals, which are still strained and struggling.
It could also mean people contracting viral illnesses that could leave them vulnerable to persistent health problems, serious illness and death.
“The flu didn’t become an afterthought,” Shaman said. “The seasonal flu has imposed and continues to impose a very heavy burden on society, a burden that we would like to control.”