US sees worst flu outbreak in 10 years: Which states are being hit hardest by 'tripledemic'?

Fears of a "tripledemic" in the U.S. seem to be coming to true, as flu hospitalizations hit their highest level in a decade, COVID cases rise following Thanksgiving gatherings, and respiratory syncytial virus (RSV) continues to sicken children across the country.

"This year’s flu season is off to a rough start,” Dr. Sandra Fryhofer, board chair of the American Medical Association, said at a Dec. 5 press briefing hosted by the Centers for Disease Control and Prevention. “Flu is here. It started early, and with COVID and RSV also circulating, it’s a perfect storm for a terrible holiday season.”

While cases of RSV, which have been straining children's hospitals since the early fall, may have peaked in some parts of the country, flu activity is surging ahead of schedule, CDC director Dr. Rochelle Walensky said at the briefing. And the number of new COVID-19 cases per day has increased 16% over the past two weeks, according to NBC News' tally.

Inpatient hospital beds in the U.S. are currently about 78% full, per data from the Department of Health and Human Services. Ten states are reporting their pediatric hospital beds are 90% full or higher, according to an NBC News analysis.

The continued shortage of health workers is also making this winter a difficult one for illnesses. Even prior to the pandemic, there were already too few health workers to go around, but it's gotten worse in the years since. In fact, previously reported that some hospitals have beds available but no staff to care for those patients.

What is a tripledemic?

The tripledemic of 2022 refers to the possibility that COVID-19, seasonal influenza and RSV will all surge at the same time. COVID-19 and the flu are certainly on the upswing, but RSV may be slowing down, per CDC data. That said, all three viruses are still continuing to cause widespread illness.

In early October, cases of respiratory viruses, including RSV, were already causing many children's hospitals to reach capacity, with one facility in Connecticut reporting its worst RSV surge in 25 years, previously reported. Data from the Centers for Disease Control and Prevention show that RSV hospitalization rates are much higher this year than in the past, but are starting to decline.

Related: Where are kids most likely to get RSV?

The number of positive RSV tests in the U.S. fell from over 19,000 the week ending Nov. 12 to 7,500 the week ending Nov. 26, per CDC data. At the Dec. 5 briefing, Walensky said RSV cases have peaked in the South and Southeast and plateaued in the Mid-Atlantic, New England and Midwest. It's not clear if the trend will hold, however.

“RSV is usually seen in January and February,” Dr. Roberto Posada, a professor of pediatrics at Mount Sinai Kravis Children’s Hospital in New York City, tells “We hadn’t seen that much in the way of RSV and even influenza over the past two years, and that may be because of masking and people not getting together.” Because of that, people have less immunity at a time when they are gathering more and masking less, Posada explains.

Influenza is also on the rise, with the U.S. seeing the highest number of hospitalizations for this time of year in a decade, NBC News reported. Roughly 78,000 people have been hospitalized with flu and 4,500 have died since early October, NBC News reported. The number of flu hospitalizations in the U.S. doubled from the second-to-last week in November to the last. Since Oct. 1, the flu has caused 8.7 million illnesses; for context, 9 million illnesses were reported for the entire 2021-2022 flu season.

And third, putting the "triple" in "tripledemic," is the steady increase in COVID-19 cases since the Thanksgiving holiday. In addition to the increase in daily new cases recorded by the NBC News tally, daily COVID-related hospital admissions increased 18% from the week ending Nov. 22 to the week ending Nov. 29, per CDC data. Experts previously told that it's likely cases will continue to increase as people gather for Christmas and New Year's and spend more time indoors as temperatures drop.

"If you add an omicron surge to the current RSV surge, there’s no place ... to put another 50 kids that need to be admitted to the hospital," Dr. Jason Newland, professor of pediatric infectious diseases at Washington University School of Medicine in St. Louis, tells

Even though flu and RSV may be a bit early, it’s typical in winter to see a surge of these viruses, Dr. Michael Angarone, associate professor of infectious diseases at Northwestern Medicine in Chicago, tells But this year is likely to be different: “What we are worried about is having the typical cold and flu seasons combined with SARS-CoV-2,” he says.

The real fear around a tripledemic is the possibility that the three viruses will peak at the same time and inundate hospitals, filling every bed and stretching staff thin, Posada adds.

What parts of the U.S. are highest risk for a tripledemic in 2022?

RSV, COVID-19 and flu are more likely to have a severe impact on parts of the country that are colder, Dr. David Buchholz, a pediatrician and founding medical director of primary care at Columbia University in New York City, tells

When the air is frigid, people are more likely to huddle indoors and keep their windows closed, which makes transmission of the viruses more likely, Buchholz says. “Where it’s warmer, people are more likely to spend time outdoors and open their windows,” he adds.

Another factor pumping up the spread of these three bugs in cold climates is the viruses’ affinity for cool, dry air, Dr. Timothy Brewer, professor of medicine and epidemiology at University of California, Los Angeles, tells In fact, this phenomenon may explain the burst of flu activity in Texas and the Southeast in early November, which experienced a cold snap right before, he says.

As of the week ending in Nov. 26, all but five states are experiencing "high" or "very high" flu activity, the CDC reported. Based on the CDC's flu activity ranking by level, New Hampshire is the only state at level 1 (also called "minimal"), and 11 states are at the highest level recorded so far, 13. These are:

  • California

  • Colorado

  • Kentucky

  • Nebraska

  • New Mexico

  • Ohio

  • South Carolina

  • Tennessee

  • Texas

  • Virginia

  • Washington

Brewer also says the parts of the U.S. with the lowest vaccination rates against COVID-19 and flu "will most likely get into trouble with these viruses,” he said. (There's no vaccine against RSV.)

Many of the Mountain and Southern states have low vaccination rates against COVID-19, per CDC data; in 15 states, including Idaho, Alabama, South Carolina, Wyoming, Tennessee and Mississippi, less than 60% of the eligible population completed the primary series, which is approved for everyone 6 months and older.

Only about 13% of the population has received the updated booster shot targeting the omicron variant, approved for people 5 and up. All COVID-19 variants circulating right now come from omicron. The CDC announced Nov. 22 that the updated booster is more effective at preventing symptomatic COVID infections in the real world than earlier doses. White House COVID-19 response coordinator Dr. Ashish Jha called it "the best protection for this winter."

Flu shot distribution is also lagging across the country. As of the week ending Nov. 26, the immunization rate is lower than at the same point in the previous two seasons. These states had the lowest flu vaccination rates during last year's season, according to data from the Kaiser Family Foundation:

  • Mississippi

  • Wyoming

  • Nevada

  • Idaho

  • Florida

How to protect yourself during a tripledemic

The best way for people to protect themselves amid the possibility of a tripledemic is to get the latest COVID-19 booster and a flu shot, Angarone says. So far, it looks like the flu vaccine this year is a good match to the strains of influenza virus currently circulating, Brewer adds. There's no vaccine for RSV, but one could be on the horizon.

Even though most people will not experience severe symptoms with RSV and the flu, “we have to be aware of others when we are sick,” Angarone says. “Even though it’s not COVID-19, you probably should not go to work and get your colleagues sick. You should make sure you are washing your hands.”

Some experts have also continued to recommend masking and opening windows at indoor, crowded events, as well as taking a rapid COVID test before holiday gatherings.

For parents of young or immunocompromised children, it's also important to know the signs of a severe RSV infection and when to seek medical care, TODAY previously reported. These are:

  • Having trouble breathing, such as the skin around the ribs sucking in or the nostrils flaring when the child tries to breathe.

  • Grunting in babies, or difficulty speaking in older kids.

  • Diminished number of wet diapers and other signs of dehydration.

  • Increased or persistent lethargy, such as a child being difficult to wake.

  • Any sign of blue around the lips.

  • Irritability, such as crying that won't stop.

The good news is RSV and influenza aren't new, so we know how to prevent and treat them, and there are vaccines available to protect against two of the three viruses that contributing to the tripledemic.

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