RSV could cause a ‘tripledemic’ – here’s what you need to know

Is a "tripledemic" on the way this winter? Some scientists think so, as an early uptick in respiratory syncytial virus (RSV) virus cases in the US and Canada emerges alongside transmission of COVID-19 and flu.

The rising numbers are concerning, as 1 in 56 otherwise healthy babies are hospitalized with RSV during their first year of life, a study published in The Lancet Respiratory Medicine says. The reason for the increase in RSV cases is that many children were shielded from common infections during lockdowns, ABC News reports.

RSV is a common respiratory virus that causes infections of the lungs and respiratory tractbabies under two and older adults with pre-existing conditions

Most people recover in a week or two, but RSV can cause serious health complications, particularly for infants and older adults. In the United States and other areas with similar climates, RSV circulation usually starts during autumn and peaks in the winter, according to the US Centers for Disease Control and Prevention (CDC), but this year case numbers have peaked early.

“There isn’t any doubt that there are going to be three active respiratory viruses this season,” William Schaffner, an infectious disease specialist and professor at the Vanderbilt University School of Medicine in the United States, told health website Prevention.com. “COVID is out there, RSV started unseasonably early and is giving paediatric hospitals a hard time in the sense that there are many children that need care.”

Each year in the United States, RSV leads to approximately 2.1 million outpatient visits among children younger than five and 58,000-80,000 hospitalizations among children younger than five, according to the CDC.

This year, about three-quarters of US hospital beds for children are full, according to the American Academy of Pediatrics. Some hospitals have set up tents to deal with excess patients or considered calling in the National Guard, The Atlantic reports.

Flu hospitalization rates are also at their worst in more than a decade, according to the CDC, with about 30 states reporting high or very high levels of the virus weeks earlier than the usual peak period. Meanwhile, as COVID-19 continues to circulate, only around 5% of eligible Americans have had their booster shots.

The tripledemic is "unsustainable", according to Melissa J. Sacco, a paediatric-intensive-care specialist at UVA Health in the US. She told The Atlantic that she has already had to "come up with creative ways to manage patients in emergency rooms or emergency departments".

It's the youngest infants facing their first RSV season who have a particularly high risk of needing to go into hospital, Dr Emily Martin, an associate professor of epidemiology at the University of Michigan School of Public Health, told The New York Times. “If a child is born in the summer and they get exposed for the first time in the winter, they are at risk of having more serious disease. But many infants didn’t experience the first RSV season on the regular schedule that they would have, particularly if they were born in or after 2020.”

The rising RSV case numbers are particularly concerning for health officials, as there’s currently no approved vaccine for the virus. That could be set to change, however.

Pfizer recently said that its new vaccine is just under 82% effective in an infant's first 90 days of life and 69% effective through the first six months of life. The company plans to submit a regulatory application by the end of 2022.

While RSV infections are most common among children, the virus can also be a danger for certain adults. An estimated 60,000-120,000 older adults in the United States are hospitalized from RSV each year, and 6,000-10,000 die, the CDC says.

It says the adults at highest risk include:

Those aged 65 or older.

Those with chronic heart or lung disease.

Those with weakened immune systems.

How can people protect themselves?

There are several steps you can take to help prevent the spread of RSV, the CDC says. If you or your child have cold-like symptoms, you should: