The flu disappeared for almost two years as the pandemic spread. But influenza is set to make a comeback in the US this year, raising long-held fears “Twindemic.”
While both the flu and the coronavirus are notoriously unpredictable, there is a good chance that COVID cases will rise again this winter, and there are troubling signs that the flu may also return.
“This could very well be the year in which we see a twin disease,” Dr. William Schaffner, an infectious disease professor at Vanderbilt University. “That is, we have an increase in COVID as well as an increase in influenza. We can have both of them affecting our population at the same time.”
The strongest indication that the flu may hit the US this winter occurred during the Southern Hemisphere winter. The flu returned in some countries, such as Australia, where respiratory infections began to rise months earlier than usual, and caused one of the worst flu seasons in recent years.
What happens in the winter of the Southern Hemisphere often foreshadows what is about to happen north of the equator.
“If we have a severe influenza season, and if the omicron variant causes predominantly mild disease, this coming winter could be a much worse flu season than COVID,” warned Schaffner.
And the combination of the two viruses can seriously overwhelm the health system, he says. Centers for Disease Control and Prevention Estimate That flu causes between 140,00 to 710,000 hospitalizations annually.
“We should be concerned,” Dr. Richard Webby, an infectious disease specialist at St. Jude Children’s Research Hospital. “I don’t think it’s necessarily a concern for hills. But we need to be concerned.”
The main reason the flu basically disappeared over the past two years was a change in behavior people took to avoid COVID, such as staying home, avoiding public gatherings, wearing masks and not traveling. It also prevented the flu virus from spreading. But those measures have mostly been abandoned.
“As community mitigation measures begin around the world and people return to their normal activities, the flu has begun to spread around the world,” Dr. Alicia Fry, who leads influenza epidemiology and prevention for CDC. “We can expect flu season this year — for sure.”
especially young children at high risk
CDC reporting That the flu is already beginning to spread to parts of the South, such as Texas. And experts caution that very young children may be particularly at risk this year.
Although COVID-19 has generally been mild for young people, the flu usually poses the greatest threat to both the elderly and children. The main strain of flu that is currently spreading, H3N2, affects the elderly badly. But health experts are also concerned about young children who have not been exposed to the flu for two years.
“You have 1-year-olds, 2-year-olds, and 3-year-olds who will all be seeing it for the first time, and none of them have any pre-existing immunity to influenza,” Dr. Helen ChuAssistant Professor of Medicine and Allergy and Infectious Diseases and Assistant Assistant Professor of Epidemiology at the University of Washington.
In fact, the flu appears to have particularly hit young people in Australia.
“We know that schools are actually the places where influenza is spread. They are actually thought to be drivers of transmission,” Chu says. “They would be the spreaders. Then they would take it to the parent’s house. The parents would take it to the workplace. They would take it to the grandparents who are in assisted living, nursing homes. And then they would be the population.” So get pretty sick with the flu.”
“I think we’re heading into a bad flu season,” Chu says.
‘Viral intervention’ could offset the risks
Some experts suspect that COVID and flu will come together in the country because of a phenomenon called “viral interference,” which occurs when infection with one virus outweighs the risk of catching another. This is an additional possible reason why the flu has disappeared in the past two years.
“These two viruses can still both happen during the same season, but my gut feeling is that they’re going to happen sequentially, rather than both at the same time,” Webby says. “So I’m less worried about twins.”
Still, Webby and others are urging people to make sure everyone in the family gets a flu shot as soon as possible, especially if flu season hits the US too early. (Most years officials don’t prompt people to get their flu shots until October.)
So far it seems that this year’s flu vaccines are a good match with circulating strains and should therefore provide effective protection.
But health officials fear fewer people than usual will get flu shots this year as anti-vaccine sentiment has fueled an increased response to COVID vaccination. flu vaccine rates already lagging behind,
“We are concerned that people will not be vaccinated. And the influenza vaccine is the best prevention tool we have,” says the CDC’s Fry.
Fry also hopes that some of the habits people have developed to fight COVID will continue and help reduce the effects 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’re sick instead of going to work. They keep their kids out of school. Schools are strict about not letting kids come to school when they’re sick. All of this Things can reduce transmission.”