The flu virtually disappeared for two years as the pandemic raged. But the flu appears poised to hit the US again this year, threatening to trigger the long-feared “twindemic.”
Both the flu and coronaviruses are notoriously unpredictable, but there are troubling signs that COVID cases are likely to spike again this winter, and the flu could return.
Dr. William Schaffner, professor of infectious diseases at Vanderbilt University, said, “This year is very likely to be the year we see a twindemic.” may affect the population at the same time.”
The strongest indication that influenza could hit the United States this winter is what happened in the Southern Hemisphere winter. The flu has returned to some countries such as Australia, where respiratory infections began to rise months earlier than usual, causing one of the worst flu seasons in recent years.
What happens in winter in the southern hemisphere often portends what happens north of the equator.
“If we have a serious flu season and the omicron variants continue to cause predominantly mild disease, this winter could be a much worse flu season than COVID,” warns Schaffner.
And the combination of the two viruses could seriously strain the health system, he says. The Centers for Disease Control and Prevention estimates that influenza causes between 140,000 and 710,000 hospitalizations each year.
“There should be concern,” said Dr. Richard Webby, an infectious disease specialist at St. Jude Children’s Research Hospital. should be concerned.”
The main reason the flu has basically disappeared over the past two years was the behavioral changes people have made to avoid COVID, such as staying home, avoiding public gatherings, wearing masks, and not traveling. This also prevented the spread of the influenza virus. However, these measures have largely been abandoned.
Alicia Fry, Ph.D., lead of influenza epidemiology and prevention at the CDC, said: “You can expect flu season this year — sure.”
Young children at particularly high risk
The CDC reports that influenza is already spreading in parts of the South, including Texas. And experts warn that very young children may be at particular risk this year.
While COVID-19 is generally milder for young people, influenza usually poses the greatest threat to both the elderly and children. H3N2, the main strain of influenza currently circulating, tends to hit older people hard. But health experts are also concerned about young children who haven’t been exposed to the flu for two years.
“Every 1-year-old, 2-year-old, and 3-year-old has the flu for the first time, but none of them have pre-existing immunity to the flu,” said Dr. Helen Chu, Adjunct Assistant Professor of Epidemiology, said:
In fact, the flu appears to have hit young Australians particularly hard.
“We know that schools are where the flu actually spreads. Schools are thought to be the engine of transmission,” Chu said. “They’re going to be spreaders. They’ll take it home to their parents. Parents will take it to work. They’ll take it to their grandparents in nursing homes and nursing homes. And those populations then get pretty sick with the flu.”
“I think we’re headed for a bad flu season,” Chu says.
‘Virus interference’ may offset risks
Some experts suspect that COVID and influenza could hit the country at the same time. This is because of a phenomenon known as “virus interference” that occurs when infection with one virus reduces the risk of infection with another virus. This is another possible reason why the flu has disappeared in the last two years.
“Those two viruses could hit in the same season, but I have a feeling they’re going to hit sequentially rather than both at the same time,” says Webby. I’m not too worried about
Nonetheless, Webby and others urge people to get everyone in their family vaccinated against the flu as soon as possible. does not work on
So far, this year’s flu vaccine appears to be well-matched with the circulating strains and should provide effective protection.
But health officials fear fewer people will be vaccinated against the flu this year, as anti-vaccination sentiment has grown following the coronavirus vaccination. Influenza vaccination coverage is already lagging.
“I’m worried people won’t get vaccinated, and the flu vaccine is the best prevention tool we have,” says Fry of the CDC.
Fry also hopes that some of the habits people have learned to fight COVID will continue and help soften the effects of the flu.
“The wild card here is that people don’t know how much mitigation they’re going to take,” Fry says. “For example, people now stay home when they are sick instead of going to work. They don’t send their children to school. All these kinds of things can reduce infection..”