What Is a 'Tripledemic'? Experts Warn COVID, Flu, and RSV May Converge This Winter

Rising flu cases, surges in respiratory syncytial virus (RSV), and the strong possibility of yet another winter COVID surge, could put the US at the center of three coinciding epidemics—or a “tripledemic”—as we head into the winter months. 

“It’s always concerning when you have three respiratory viruses—RSV, influenza, and COVID—rising at the same time,” White House COVID-19 Response Coordinator Ashish Jha, MD, MPH, said in an interview with CBS News. “If all three of them rise at the same time, again if people are not vaccinated, then we can start seeing a lot more hospitalizations.”

While most cases of these three viruses are typically on the milder side, together they may be especially worrisome for infants and the elderly, as well as immunocompromised people and those who aren’t vaccinated—and it could put additional strain on the US healthcare system. 

Here’s what to know about a possibly impending tripledemic, including why these viruses are resurfacing with such force, who might be at the greatest risk of getting sick in the weeks and months ahead, and how to keep families and communities safe. 

Fewer COVID Precautions May Fuel Rise of Other Viruses

Though respiratory viruses tend to rise during colder months, flu and RSV cases seem to be increasing earlier than usual this year or at a different time.

Flu season typically peaks between December and February, the Centers for Disease Control Prevention (CDC) said, and prior to the pandemic, the same used to be true for RSV. 

But as of now, flu rates are much higher this year than every season since 2017. And as for RSV, rates are fast approaching peaks from the last surge which was in July, August, and September of 2021.

The most likely reason for this, experts said, is that our adherence to COVID precautions kept us safe from more than just the coronavirus. Masks, social distancing, and other measures kept other respiratory viruses low and, in the case of RSV, disrupted seasonal patterns. 

“The immunity cycles are all whacked out,” Peter Chin-Hong, MD, professor of medicine and infectious disease specialist at the University of California San Francisco School of Medicine, told Health. “Restrictions have been dropped and more people are getting together. It is getting colder, even though it's not exactly the season. But RSV is taking advantage.”

And though people can build immunity to the flu and to COVID with booster shots, there’s no vaccine currently available for RSV. This leaves infants and the elderly at an elevated risk, explained William Petri, MD, PhD, professor and physician of infectious diseases at the University of Virginia School of Medicine.

“There's less pre-existing immunity in children because, for the most part, wearing masks and social distancing protected them from RSV infection over the last two years, making them perhaps more vulnerable to being infected now,” Dr. Petri told Health. 

Adults, teens, and older children also likely have waning or no immunity to RSV following pandemic precautions, and they can pass the virus to younger kids and infants, said Dr. Chin-Hong. What probably presents as a mild cold to them can be much more intense for infants and the elderly. 

Kids spending more time in daycares and schools this fall is also likely aiding in exposure and, by extension, driving case numbers up, explained Arlene Seña, MD, MPH, professor of medicine in the division of infectious diseases at University of North Carolina School of Medicine. 

Issues Could Arise if Peaks Converge

For most people, COVID, the flu, and RSV are all relatively mild illnesses that look similar—they’re all respiratory viruses that can cause symptoms like fever, cough, and congestion or a runny nose, among others.

Though most people have had COVID, flu, or RSV at least once, if not multiple times throughout their lives, the viruses can still be especially dangerous for some, including infants and the elderly, and immunocompromised people. 

There are concerns that if each virus surges and peaks around the same time, this “tripledemic” could be a huge problem, particularly for those who need treatment at hospitals or healthcare facilities. 

“Pediatric hospitals haven't typically, traditionally been large capacity hospitals, and they also vary from community to community,” said Dr. Chin-Hong. “A lot of the things that we saw in adult hospital care, it's already starting in the pediatrics—they don't have a large workforce. It's just burnout [...] there's less give in that system.” 

Already, some pediatric hospitals are reporting capacity issues. 

“The continued influx of patients in the emergency departments seeking care for the flu, RSV and other pulmonary infections, as well as the continued mental and behavioral health crises coupled with the growing medical workforce crisis—we simply do not have enough pediatric specialists to staff the beds in our children's hospitals,” said Children’s Hospital Association CEO Mark Wietecha in a press release.

If flu, COVID, and RSV were to peak around a similar time, this could certainly tax hospitals and healthcare systems to an even greater degree. And strained hospital resources often mean worse care for patients.

Unfortunately, it’s not possible to predict exactly when each of these respiratory viruses will peak, said Dr. Chin-Hong. 

COVID case numbers are currently declining, but experts are expecting a winter surge around the holidays similar to trends from the last two years, said Dr. Petri. And with the rise of the newer variants—BA.4.6, BQ.1, BF.7 and others—bivalent vaccines may also not prevent people from getting infected with COVID, he added, though they do still prevent serious illness. Experts don’t know if or when the US could see a boom in cases, though. 

And because flu and RSV are similarly unpredictable this year, it’s hard to know if we’ll reach a truly dangerous point of “tripledemic” where the three viruses will peak together. 

How to Protect Yourself This Winter

In the face of a possible “tripledemic,” experts are again recommending that people protect themselves against flu and COVID by getting vaccinated.

Dealing with RSV, unfortunately, is a bit more complicated. 

“​​RSV is like the hole in our armor because there's no vaccine and there's no therapy,” said Dr. Petri.

People can get treatments for the flu and COVID in hospitals if they start experiencing severe symptoms, but RSV care at hospitals is just supportive, according to Dr. Chin-Hong. There is a monoclonal antibody treatment to help protect severe disease, but it’s typically only used for children who are immunocompromised. And, Dr. Petri added, it’s of limited effectiveness.

Because of the gaps in prevention and treatment for RSV, there may be some good pandemic-era transmission prevention measures that could be useful as case numbers for RSV, flu, and COVID increase. 

“Don't go to work if you’re sick, don’t go out. If you are, wear a mask, wash your hands religiously,” Dr. Chin-Hong said, “We've de-emphasized washing hands for COVID but for RSV, influenza, other respiratory viruses, it's actually really, really important.” 

Being extra careful and masking around the elderly and young infants is also a good idea, he added, as is wiping down surfaces if you’re sick. 

However, the threat of this “tripledemic” isn’t grounds for re-implementing the strictest of COVID measures, according to Dr. Petri. It would be most useful to keep an eye on CDC case counts for all viruses in your community if possible and make decisions about which prevention methods to use from there. 

“It's hard just to stay masked all the time,” Dr. Petri said. “If we could use masks when we think they're going to be of the greatest benefit, when transmission is the highest, I think that [would] probably improve adherence to mask wearing and just be a lot easier for all of us to comply.”

And even though we have the least amount of tools to protect against it, RSV is much less transmissible than COVID, said Dr. Chin-Hong. Another silver lining is that a vaccine for RSV could be just a few years away, added Dr. Petri. 

Though the risk of a bad fall and winter respiratory virus season is very real, it may just mean we have to be a bit more vigilant about leaning on vaccinations, staying home when we’re sick, and maybe sometimes masking to make sure that hospitalizations don’t climb too high. And, it’s certainly not too late to get the vaccines that are available. 

“It's a great time to get your flu and your COVID boosters,” said Dr. Petri. “Just because we're really going to be getting into the time when transmission is highest and [it] should be nice to have your immunity boosted to prepare for that.”