Flu season could be tough this year: Vaccines


Health officials predict this winter could see an active flu season in addition to possible increases in COVID. In short, it’s a good year to be a respiratory virus. Left: Image of SARS-CoV-2 omicron virus particles (pink) replicating inside an infected cell (teal). Right: Image of an inactive H3N2 influenza virus.

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NIAID/Science Source


Health officials predict this winter could see an active flu season in addition to possible increases in COVID. In short, it’s a good year to be a respiratory virus. Left: Image of SARS-CoV-2 omicron virus particles (pink) replicating inside an infected cell (teal). Right: Image of an inactive H3N2 influenza virus.

NIAID/Science Source

The flu virtually disappeared for two years while the pandemic raged. But the flu appears poised to make a comeback in the United States this year, threatening to spark a long-feared “twindemia.”

While the flu and the coronavirus are notoriously unpredictable, there’s a good chance that COVID cases will spike again this winter, and troubling signs that the flu could make a comeback as well.

“This could be the year we see a twindemic,” says Dr. William Schaffner, a professor of infectious diseases at Vanderbilt University. “That is, we have an increase in COVID and simultaneously an increase in influenza. We could have both affecting our population at the same time.”

The strongest indication that flu could hit the US this winter is what happened during the Southern Hemisphere winter. The flu returned to some countries, including Australia, where respiratory infections began to rise months earlier than normal, leading to one of the worst flu seasons in recent years.

What happens in the southern hemisphere winter often foreshadows what will happen north of the equator.

“If we have a severe flu season, and if omicron variants continue to cause mostly mild disease, this coming winter could be a much worse flu season than COVID,” warns Schaffner.

And the combination of the two viruses could seriously strain the healthcare system, he says. The Centers for Disease Control and Prevention estimates that the flu causes between 140,000 and 710,000 hospitalizations annually.

“We should be concerned,” says Dr. Richard Webby, an infectious disease specialist at St. John’s Children’s Research Hospital. Jude “I don’t think he’s necessarily worried about running for the hills. But we have to be worried.”

The main reason the flu basically disappeared in the last two years was the behavioral changes people made to avoid COVID, such as staying home, avoiding public gatherings, wearing masks, and not traveling. This prevented flu viruses from spreading as well. But these measures have been largely abandoned.

“As community mitigation measures begin to roll out around the world and people return to their normal activities, the flu has begun to circulate around the world,” says Dr. Alicia Fry, who leads ​​influenza epidemiology and prevention for CDC. “We can expect a flu season this year, for sure.”

Young children at particularly high risk

The CDC reports that the flu is already starting to spread to parts of the South, including Texas. And experts warn that very young children may be especially at risk this year.

While COVID-19 has generally been mild for young people, the flu usually poses the greatest threat to both the elderly and children. The main flu strain currently circulating, H3N2, tends to hit the elderly hard. But health experts are also concerned about young children who haven’t been exposed to the flu for two years.

“You have 1-year-olds, 2-year-olds, and 3-year-olds who are seeing it for the first time, and none of them have any pre-existing immunity to the flu,” says Dr. Helen Chu, assistant professor of medicine and allergy and infectious diseases and adjunct assistant professor of epidemiology at the University of Washington.

In fact, the flu seems to have hit particularly young people in Australia.

“We know that schools are really the places where flu spreads. They’re really considered the engines of transmission,” says Chu. “They will be the spreaders. Then they will take it home to parents. Parents will then take it to the workplace. They will take it to grandparents who are in assisted living, nursing home. And then these populations will. then get quite sick with the flu.”

“I think we’re headed for a bad flu season,” Chu says.

“Viral interference” could offset the risks

Some experts doubt that COVID and the flu will hit the country simultaneously because of a phenomenon known as “viral interference,” which occurs when infection with one virus reduces the risk of catching another. This is an additional possible reason why the flu disappeared in the last two years.

“These two viruses can still both happen in the same season, but my intention is that they will happen sequentially rather than both at the same time,” says Webby. “So I’m less worried about twindemia.”

However, Webby and others are urging people to make sure everyone in the family gets the flu shot as soon as possible, especially if flu season is also coming soon in the US. (Most years, officials don’t start pushing people to get flu shots until October.)

So far, this year’s flu vaccines appear to be a good match for the circulating strains and should therefore provide effective protection.

But health officials fear fewer people will get a flu shot this year than usual because of anti-vaccine sentiment that has risen in reaction to the COVID vaccinations. Flu vaccination rates are already lagging.

“We worry about people not getting vaccinated. And the flu shot is the best prevention tool we have,” says the CDC’s Fry.

Fry also hopes that some of the habits people developed to fight COVID will continue and help reduce the impact of the flu.

“The wild card here is that we don’t know how many mitigation practices people will use,” Fry says. “For example, people now stay at home when they are sick instead of going to work. They keep their children out of school. Schools are strict about not letting children come to school if they are sick . All these kinds of things could reduce transmission. .”

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