If trends in the Southern Hemisphere — historically seasonal news for the U.S. — hold true, the U.S. could be in for a tough flu season this year.
This is not the first time since the start of the Covid pandemic that experts have warned of a bad flu season or even a “twindemic”: a flu season on top of a winter surge of Covid. But so far this has not happened.
This year’s highlight is the first time since the pandemic began in Australia that the flu is on the rise. Australia’s flu season may be an indicator of what’s to come in the US
Australia is coming to the end of its worst flu season in five years, according to the latest report from the country’s Department of Health and Aged Care.
“We’re watching all the countries in the Southern Hemisphere carefully, hopefully we’ll get some insight, but it’s by no means perfect,” said Dr. Alicia Frye, chief of epidemiology and prevention at the Centers for Disease Control and Prevention.
Still, he said, the CDC is “highly alert” for signs of an early and/or aggressive flu season in the U.S.
According to the CDC, an average of 41 million people contract the flu each year, resulting in about 52,000 deaths.
Warning signs for winter
Australia’s flu season has started earlier than usual, which could be a sign of a tougher season ahead.
“The earlier it starts, the worse it is,” said Dr. Robert Citronberg is the executive medical director of infectious disease and prevention at Advocate Aurora Health in Illinois. This is often a function of time – the more the current circulates, the more damage it does to the population.
Australia’s flu season has also hit children hard, according to the country’s health agency. This year, children between the ages of 5 and 9 had the highest rate of flu cases, followed by those 4 and under and teenagers.
Australian health authorities say it is too early to say whether their flu vaccine is suitable for the flu strains.
The flu vaccine to be offered in the US this year protects against two strains of influenza A and two strains of influenza B.
How vulnerable populations can prepare
Normally, people are exposed to different strains of influenza each year, which helps build immunity against the virus.
However, due to less flu in the last two seasons, that immunity has weakened. Experts say young children may be particularly at risk because their immune systems are less susceptible to the virus.
“There are many young children who have not had the flu in the last two years,” said Dr. James Cutrell, an infectious disease expert at Southwestern Medical Center in Dallas. “It makes them more likely to get it and then spread it to other people.”
Cutrell said people shouldn’t panic about the coming flu season, but “it’s time for people to be prepared.”
This mainly includes updates on flu and Covid vaccines.
Protection against one viral infection can help protect against another, and vice versa, said Dr. Robert Citronberg, Executive Medical Director of Infectious Diseases and Prevention at Advocate Aurora Health.
Both Covid and the flu can cause “significant lung inflammation,” Citronberg said. “Once you have pneumonia, you’re more susceptible to other infections or pathogens.”
Doctors’ offices and pharmacies across the U.S. will be shipping flu shots in the coming weeks. According to Frye of the CDC, September or October is the best time for most people to get the shot.
Two groups in particular should get them as early as possible, he said: young children, who need two shots this year, and women in their third trimester of pregnancy.
“It’s a good idea to get the vaccine before they’re born so that the baby gets some of the antibodies that the mother has developed and protects the baby,” Fry said. Babies under 6 months are not eligible for the flu vaccine.
According to the CDC, children under 9 who have never had a flu shot should get two doses at least four weeks apart this year.
In addition, children of that age who received only one shot during the previous flu season may need two shots this year.
Historically, Americans have been reluctant to get a flu shot. According to the CDC, about half of the US population will get a shot during 2020-21. And while there’s no guarantee they’ll prevent infection, studies have shown they can reduce the risk of hospitalization or death from severe flu.
“The flu cannot be completely prevented by the vaccine, but it can be controlled,” Citronberg said. “If we get a significantly lower number of flu shots this year, that could affect how many cases we have and how severe they are.”
If that happens, Citronberg predicted, “we’ll have our hands full.”
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