Why were RSV, flu so severe this season? KSAT Explains

While COVID is still a concern, it’s the viruses that have circulated for decades that caused a spike in hospitalizations

SAN ANTONIO – If it feels like you’ve been playing a “guess the virus” for months now, it’s not just you.

Between the common cold, flu, RSV, COVID (and we can’t forget our dear, seasonal pal Mountain Cedar), it’s been tough to distinguish what’s what this cold and flu season.

RSV, or Respiratory Syncytial Virus, has been especially rough on children

And it arrived early.

“We had we had a very unusual summer RSV surge,” said Dr. Tess Barton, Associate Professor of Pediatric Infectious Diseases at UT Health San Antonio.

Flu season arrived ahead of schedule, too, in early October.

Hospitals filled up fast nationwide as children, and some adults, dealt with the double whammy.

So, why was it so bad?

Another nasty virus is taking the blame: COVID.

“The thing that’s most likely is that we sort of upset our normal patterns of getting infections and getting, you know, some immunity to infections during the pandemic through a combination of staying away from activities and masking,” Barton said.

RSV typically hits infants hardest.

They have tiny airways that can get clogged with mucus and they can’t cough like adults or older children to clear that mess.

It can cause bronchiolitis, which is the clogging of the airways that go down into the lungs.

“They might have trouble breathing or have rapid breathing or they might actually have a bluish tinge because they’re not oxygenating well,” said Dr. Bryan Alsip, Chief Medical Officer at University Health.

During the pandemic, babies who would normally be exposed to RSV and build up some immunity didn’t get that exposure because of the precautions we needed to take for COVID.

So RSV came roaring back this season as post-pandemic normalcy returned.

Along with the flu.

“Last year it wasn’t bad at all for the flu,” Alsip said. “And then the year before that it was almost nonexistent.”

What’s the difference between the flu and RSV?

Both the flu and RSV are aerosolized viruses, meaning they spread by someone coughing, breathing out the particles, and the next person inhaling those particles.

Those particles get into the nose and symptoms follow, which can be similar for flu and RSV.

They’re often cough, fever, chills, and body aches.

The flu is infamous for opening the door for a second infection.

“It really triggers your immune system to make a big reaction and it kind of distracts your immune system, which also makes it easier for bacteria and other other infections to kind of come along right after and wipe you out,” Barton said. “So it’s not uncommon to see somebody get flu and then get a second infection immediately afterwards.”

The flu vaccine is formulated every year to prevent severe illness.

What are Flu A and Flu B?

“The flu vaccine is typically a live attenuated vaccine,” said Joanne Turner, Executive Vice President of Research at Texas Biomedical Research Institute.

“It means it’s been made to be less virulent or less dangerous,” Turner added. “And then we will genetically engineer it essentially to look like whatever the seasonal flu is that’s coming out the following year.”

The vaccine does not contain the actual, infectious flu virus. The vaccine doesn’t infect a person, though some people may feel crummy after getting the shot.

That’s your immune system at work.

“You want your body to think it’s got a real infection,” Turner said. “So that means the virus will turn on all the same pathways that it would if you saw the real flu and then it just can’t cause disease.”

Roughly 100 labs across 100 countries report flu trends to the World Health Organization.

“We’ll often see a flu outbreak in a different country before it would come to the US, and we’ll see the trends of which ones are circulating and then they’ll project those,” Turner said. “They will try and make several of them. And as the season gets closer and closer to the US they’ll be able to predict more readily what’s going to be the flu of that year.”

That prediction of which flu strains will be most common for the season is the combination that goes into the flu shot.

Those types of flu are commonly labeled “A” and “B” for the year.

The flu vaccine takes about six months to make and test, so researchers are working on the vaccine for the next season while we’re still in the current one.

RSV lacks a vaccine and has a challenging history

There is no approved vaccine for RSV currently, though one is being developed.

But there is a challenging history associated with work on an RSV vaccine.

Back in the 1960s, researchers developed one.

“They formalin-fixed the virus, which means they just killed it and they gave a killed virus to babies. So it’s not infectious,” Turner said. “But somehow that vaccine ended up making infection worse. So as soon as that baby saw RSV infection for the first time, it actually responded much more rapidly and more potently and a lot more children got hospitalized.”

Decades later, Pfizer is now creating a vaccine to protect infants from RSV by vaccinating pregnant women.

“Women pass on antibodies across the placenta that help to protect the baby in the first few months of life,” Barton said.

“The baby, when it’s born, will have those antibodies circulating and it can protect them up to about six months of age, which is really a critical time when you don’t want them to get RSV,” Turner said.

A monoclonal antibody for RSV is also being developed and tested.

It’s called Nirsevimab that was created by Astrazeneca and still needs to be approved by the FDA.

How to treat flu & RSV

Fortunately, RSV cases have peaked in the U.S. and flu cases are declining as of mid-January.

But there are a few things to keep in mind if you have to deal with either.

Prescription Tamiflu is a treatment used for both children and adults infected with the flu.

Rest, hydration and good nutrition are also important.

Those are also the main treatments for RSV. There is no prescription for that virus.

Time is part of the battle, too.

RSV symptoms tend to be at their worst between day three and five of the illness.

Signs a child is struggling to breathe

Look at the base of the child’s ribs. If you notice the muscles directly underneath are pulling or tugging as they breathe, its time to get medical help.

Also look for:

  • tugging or pulling at the base of the throat between the collar bones
  • a blue hue to the skin or nails
  • heavy breathing with the belly

All are signs it is time to get medical attention immediately.

About the Authors

Myra Arthur is passionate about San Antonio and sharing its stories. She graduated high school in the Alamo City and always wanted to anchor and report in her hometown. Myra anchors KSAT News at 6:00 p.m. and hosts and reports for the streaming show, KSAT Explains. She joined KSAT in 2012 after anchoring and reporting in Waco and Corpus Christi.

Valerie Gomez is lead video editor and graphic artist for KSAT Explains. She began her career in 2014 and has been with KSAT since 2017. She helped create KSAT’s first digital-only newscast in 2018, and her work on KSAT Explains and various specials have earned her a Gracie Award from the Alliance for Women in Media and multiple Emmy nominations.

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