Cases of the flu, that once annual viral intruder that was regularly the country’s worst annual health crisis, is showing signs of waking up again this fall.
But, experts say, it is far too early to say if the country will have a normal – i.e., bad – flu season or a repeat of last year, when the flu all but disappeared amid the COVID-19 pandemic.
This flu season is starting out more like the seasons before the pandemic. About 2% of all visits to doctors and outpatient clinics through Nov. 13 were flu or flu-like illnesses, compared to about 1.4% a year ago, the CDC says. Cases so far are being counted in the hundreds – 702 through Nov. 13.
Still, while cases are low, they are increasing, the agency says. The spread of flu is already high in New Mexico and moderate in Georgia. The rest of the country is seeing little activity, according to the CDC.
This time last year, cases of flu, hospitalizations and deaths were down dramatically, despite fears that a drastic ''twindemic" could occur if cases of COVID-19 and influenza increased greatly, and in tandem. The comparisons of last year's flu season statistics to previous years are startling — in a good way.
In the 2019-2020 season, more 22,000 people in the U.S. died from flu; last year, deaths decreased to about 700 for the 2020-2021 season.
So, what might happen this year? Will flu be a no-show once again? Several top experts say it’s complicated:
"It's a hot question and I'd love to give you a concrete answer. But everyone is having trouble predicting." -- Stuart Ray, MD, professor of medicine and infectious disease specialist at Johns Hopkins Medicine in Baltimore.
"It's very hard to predict exactly where the flu season will land. What seems to be the case is that it will be worse than last year, but it's unclear whether or not it will be an ordinary flu season." -- Amesh Adalja, MD, senior scholar at the Johns Hopkins Center for Health Security.
"There will be flu, but I can't tell you how bad it will be." We do know that flu will be back." -- William Schaffner, MD, infectious disease specialist and professor of preventive medicine at Vanderbilt University Medical Center in Nashville.
Already, Schaffner says, “we are beginning to hear about some outbreaks."
One outbreak triggering concern is at the University of Michigan, Ann Arbor, where 528 flu cases have been diagnosed at the University Health Service since Oct. 6. The CDC sent a team to investigate the outbreak. Florida A&M University and Florida State University have also seen large outbreaks this month.
Outbreaks on college campuses are not surprising, Schaffner said. "That’s a population that is under-vaccinated," he says, and students are often in close quarters with many others. University of Michigan officials said 77% of the cases are in unvaccinated people.
Predictions about this year's flu season also have to take into account that mask wearing and social distancing that were common last year, but have become less common or sometimes nonexistent this year.
Despite uncertainty about how this year's flu season will play out, several changes and advances in play for this year's flu season are aimed at keeping illness low.
The composition of the vaccines has been updated — and each vaccine targets four viruses expected to circulate.
The flu vaccine and the COVID vaccines can be given at the same time.
The CDC has updated guidance for timing of the flu vaccine for some people.
A new dashboard is tracking flu vaccination rates nationwide, and the CDC has an education campaign, fearing the importance of the flu vaccine has taken a back seat with the attention largely on COVID and its vaccine since the pandemic began.
What's in This Year's Vaccine?
This year, all the flu vaccines in the U.S. are four component (quadrivalent) shots, meant to protect against the four flu viruses most likely to spread and cause sickness this season.
The FDA's Vaccines and Related Biological Product Advisory Committee (VRBPAC) selects the specific viruses that each year's vaccine should target. To select, they take into account surveillance data with details about recent influenza cultures, responses to the previous year's vaccines and other information.
Both the egg-based vaccines and the cell- or recombinant-based vaccines will target two influenza A strains and two influenza B strains. Options include injections or a nasal spray.
Several of the formulas are approved for use in those age 65 and up, including a high-dose vaccine and the adjuvanted flu vaccine. The aim of each is to create a stronger immune response, as people's immune systems weaken with age. However, the CDC cautions people not to put off the vaccination while waiting for the high-dose or adjuvanted. Getting the vaccine that's available is the best thing to do, experts say.
In general, September and October were good times for flu vaccinations, the CDC says. While it's ideal to be vaccinated by the end of October, it still recommends vaccinating later than that rather than skipping it.
Even if you are unvaccinated in December or January, it's still a good idea to get it then, Schaffner agrees. You would still get some protection, he says, since ''for the most part in the U.S., flu peaks in February." But he stresses that earlier is better.
While children can get vaccinated as soon as doses are available — even July or August — adults, especially if 65 and older, because of their weakened immune systems, should generally not get vaccinated that early. That's because protection will decrease over time and they may not be protected for the entire flu season. But, early is better than not at all, the CDC says.
Some children ages 6 months to 8 years may need two doses of flu vaccine. Those getting vaccinated for the first time need two doses (spaced 4 weeks apart). Others in this age group who only got one dose previously need to get 2 doses this season.
Early vaccination can also be considered for women in the third trimester of pregnancy, because the immunization can help provide protection to their infants after birth. Infants can't be vaccinated until age 6 months.
Two Arms, Two Vaccines
With millions of Americans now lining up for their COVID-19 boosters, experts urge them to get the flu vaccine at the same time. It's acceptable to get both vaccines the same day, experts agree.
"You can [even] do 2 in one arm, spaced by an inch," says L.J. Tan, PhD, chief policy and partnership officer, Immunization Action Coalition, an organization devoted to increasing immunization rates. "We co-administer vaccines to kids all the time."
And, Tan says, ''the flu vaccine is not going to amplify any reaction you would have to the COVID vaccine."
According to the CDC National Flu Vaccination Dashboard, about 162 million doses of flu vaccine have been distributed as of Nov. 5.
It expects about 58.5% of the population to get a flu shot this season, up from about 54.8% last season.
Undoing the "Flu Isn't Bad" Thinking
One common misconception, especially from parents, is that ''the flu is not bad, it doesn't cause serious problems," says Flor M. Munoz, MD, MSc, medical director of transplant infectious diseases at Texas Children's Hospital in Houston.
"Flu by itself can be serious," she says. And now, with COVID, she says, ''we do worry. If someone got both infections, they could get quite sick."
Among the potential complications in kids, especially those under 5 years, are pneumonia, dehydration, brain dysfunction and sinus and ear infections.
The vaccine for flu, like for COVID, isn't perfect, she also tells parents. "In a good year, it gives 60 to 70% protection. " But it can be much less protective than that, too. Even so, "if you get vaccinated and still get the flu, you will have milder illness."
Anti-Virals to the Rescue
When flu symptoms — fever, cough, sore throat, runny nose, body aches, headaches, chills and fatigue — appear, anti-viral treatments can lessen the time you are sick by about a day, according to the CDC. They are available only by prescription and work best when started within 2 days of becoming sick with flu.
Four antiviral drugs to treat flu are FDA-approved, including:
Oseltamivir phosphate (generic or as Tamiflu)
Baloxavir marboxil (Xofluza)
Depending on the drug and method of administration, the drugs are given for 1 to 5 days, generally, but sometimes longer than 5 days.
Track Local Flu Rates
Ray of Johns Hopkins suggests keeping an eye on how widespread flu is in your community, just as we've gotten used to tracking COVID rates, and then taking precautions such as masking up and social distancing. "Maybe we are a little more nimble now in responding to risk," he says, given the practice gotten with COVID.
He says adapting these habits in responding to flu outbreaks would be helpful—and more natural for most people than in the past. ''I don’t think it was usual ever, 3 years ago, to see people out in masks when flu rates were high."
Stuart Ray, MD, professor of medicine in the division of infectious diseases, Johns Hopkins Medicine, Baltimore.
William Schaffner, MD, medical director, National Foundation for Infectious Diseases; professor of preventive medicine and infectious disease specialist, Vanderbilt University Medical Center, Nashville, TN.
Amesh Adalja, MD, senior scholar, Johns Hopkins Center of Health Security, Baltimore.
L.J. Tan, PhD, MS, chief policy and partnership officer, Immunization Action Coalition, St. Paul, MN.
Flor M. Munoz, MD, MSc, associate professor of pediatrics and infectious diseases, Baylor College of Medicine; medical director of transplant infectious diseases, Texas Children's Hospital, Houston.
CDC: "What You Should Know About Flu Antiviral Drugs," "Increasing Flu Activity in Some States, Especially Among Young Adults," "Frequently Asked Influenza (Flu) Questions: 2021-2022 Season,'' "National Flu Vaccination Dashboard," "Estimated Flu-related Illnesses, Medical Visits, Hospitalizations and Deaths in the United States—2019-2020 Season," "Influenza (Flu) Vaccine and Pregnancy."
University of Michigan: "CDC on U-M campus to research flu cases."
Scientific American: "Flu Has Disappeared for More than a Year."
JAMA Network: "Influenza's Unprecedented Low Profile During COVID-19 Pandemic Leaves Experts Wondering What This Flu Season Has in Store."
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Cite this: This Year's Flu Season: Repeat of Last Year or a 'Twindemic?' - Medscape - Nov 19, 2021.