Is It Going To Be Another Bad RSV Season? Pediatricians Assess The Numbers

Talk to any parent during the late fall and winter months, and they will probably mention some illness, like respiratory syncytial virus (or RSV), going around their child’s school or day care. But even if parents feel that the situation is dire, when doctors are weighing the gravity of the current RSV season, they’re not focusing on mild cases — they are looking at hospital numbers and how RSV is impacting available health care resources amid other seasonal respiratory viruses. The severity of the RSV season “has to do with the number of cases that are circulating and if it’s enough for emergency rooms and hospitals to handle the volume of patients that come in need of attention or not,” explains Dr. Roberto Posada, M.D., a pediatric infectious disease specialist at Mount Sinai Kravis Children’s Hospital. “Last year was particularly bad also because it coincided with influenza and with COVID,” he adds of the tripledemic that plagued health care facilities.

So exactly how bad will this year’s RSV season end up being? It’s hard to say. While many doctors agree that cases have been on the rise, the spread and severity level is often regional and can change throughout the season. “Unlike seasonal influenza, it is much harder to predict the severity of each RSV season. Additionally, since the onset of the COVID-19 pandemic, we have seen many shifts in typical epidemiological patterns for RSV overall,” explains Dr. Priya Soni, M.D., a pediatric infectious disease specialist at Cedars-Sinai Guerin Children’s. “This is why it is best to be prepared, and it is important for parents to understand some of the warning signs and preventative measures they can take to protect their infants this winter.”

Here’s how this RSV season is measuring up to others, when you should be concerned, and what you can do to protect your family.

When exactly is RSV season?

RSV season typically starts in the fall, peaks in the winter, and tapers off in the spring, but doctors say that the beginning and end of the season can be impacted by external factors — for instance, the lifting of COVID-19 precautions caused an earlier start to last year’s season — and vary according to region. For example, doctors note that Florida usually has an earlier onset than other regions (although they aren’t exactly sure why), while the West Coast usually sees peaks in January or February.

Rates were recently highest in the South while climbing across the country, notes Dr. Katie Lockwood, M.D., a pediatrician at Children’s Hospital of Philadelphia. “In some seasons, we see earlier peaks or a concentration of cases at a particular time rather than spread throughout the season, which then makes it a particularly bad season because doctors’ offices and hospitals are busier than usual and more illnesses spread through day cares and schools.”

Although nearly all children will have been infected by RSV by the time they are 2 years old, the Centers for Disease Control (CDC) notes that each year RSV leads to approximately 58,000 to 80,000 hospitalizations among children younger than 5 (making it the most common cause of hospitalization in infants) and 60,000 to 160,000 hospitalizations among adults 65 and older.

What does this RSV season look like compared with others?

We are still in the thick of RSV season, as traditionally RSV tends to peak from late December to mid-February, so there is no final verdict yet on the severity of this season. Numbers, though, have been rising, with pediatrician Dr. Rebekah Diamond, M.D., noting both bed shortages in her NYC hospital and, in general, just “a lot of sick kids.” As for what RSV looks like this year, she adds that “right now it seems to be the typical symptoms and presentation by age group, but there is always variability across the country.”

In general, the doctors have yet to see the severity of this season surpass that of last year’s tripledemic, during which a wave of RSV, COVID-19, influenza, and other viruses hit children all at once and many COVID restrictions (which prevented children from exposure to COVID and other infections like RSV) were simultaneously lifted. This caused more first-time exposure and therefore less immunity to these viruses. It also resulted in last year’s season both starting earlier and peaking faster than usual. This is reflected in the data from the RSV Hospitalization Surveillance Network (RSV-NET), which shows that last season, RSV hospitalizations reached an especially high peak in mid-November.

“Last year was particularly severe because there was a large cohort of children who had not experienced RSV during the pandemic, leaving many children non-immune to the virus,” explains Dr. Lori Handy, M.D., associate director of the Vaccine Education Center at Children’s Hospital of Philadelphia. “This season, we anticipate that trends will normalize and resume a more typical seasonal pattern, as children are being exposed to the virus at typical rates with interactions such as day care and gatherings without masks.”

Likewise, Posada notes that this year’s RSV “rates have been gradually increasing, but not out of the range of what is expected every winter.” Of course, no one can predict how severe the rest of the season will be, as rates vary by region and where we are in the season, but right now it doesn’t seem like many doctors are alarmed by current trends.

Who is most at risk?

For many, RSV will present itself like a bad cold with a cough, runny nose, and congestion. But both the very young and the very old are at risk for severe illness from RSV. It is most dangerous in newborns and young infants (and less so as they get into and through the toddler years), Diamond explains, because they are most susceptible to developing severe cases of bronchiolitis (congestion and inflammation of the small lower airways of the lung that makes breathing difficult). Pneumonia is also a possible complication. Difficulty breathing (which can include wheezing and/or a visible retraction of the muscles while taking a breath), along with dehydration, low oxygen saturation in the blood, and fever in babies younger than 2 months) are reasons for children being admitted to the hospital. (You should always call a doctor immediately for fever in all infants younger than 12 weeks or for any child if it is more than 104 degrees.)

Those at greatest risk for severe infection include:

• Infants younger than 12 months (especially 6 months and younger)
• Premature infants (born before 37 weeks)
• Children younger than 2 years with chronic lung disease or congenital heart disease
• Children with weakened immune systems or neuromuscular disorders, including those who have difficulty swallowing or clearing mucus secretions
• Children with asthma or asthma-like conditions
• Adults 60 and older
• Adults with chronic heart and lung conditions, weakened immune systems, or other underlying conditions

What you can do to protect your family

While there is no treatment for those already infected with RSV, prevention is often the best proactive medicine in avoiding illness or at least lessening the risk of a severe case. This year that includes two available recombinant RSV vaccines — one for adults older than 60 and one given to pregnant people so that they can pass RSV antibodies along to the fetus and have their baby born with increased immunity from contracting a serious RSV infection.

Although doctors cite shortages and supply issues, there is also a new preventive monoclonal antibody called nirsevimab to be administered once during RSV season. It is recommended for all infants younger than 8 months who weren’t born to a person who received the vaccine during weeks 32 to 36 of pregnancy (and up to 19 months for certain children). There was already a monoclonal antibody treatment, called palivizumab, available for high-risk infants.

Due to both the way data is collected, vaccine uptake, and supply shortages (specifically for nirsevimab), the experts agree that it is too early to tell if this year’s rates are being impacted by the number and efficacy of new RSV vaccines and monoclonal antibodies. The hope, though, is that vaccines and antibodies will help curb the spread of severe infection.

Of course, a bit of common sense when it comes to avoiding the spread of germs — especially since RSV in particular can live a long time on surfaces — also goes a long way. This includes practicing good hand hygiene, avoiding crowded places especially if there is a surge of illness in your area, and staying home if you or your child is sick.

“Because young children are the primary individuals who are transmitting the [RSV] infection and they often are surrounded by other children in child care and school settings, holiday gatherings alone don’t necessarily lead to major changes in epidemiology,” explains Handy. That said, though, there is an increased risk for respiratory infections whenever people are traveling and getting together, especially when they are gathering indoors in the colder months.

As for what is to come? “We have not yet seen a clear peak to know the full extent of how children will be impacted this season,” Handy adds. It is possible, however, that we are “just at the peak,” as CDC Director Dr. Mandy Cohen recently told ABC news, noting that RSV cases are quite active in general, despite numbers possibly starting to decline in the southern and southeastern states. All that said, no one can predict with certainty whether we’ve seen the “worst” of RSV this season or not, as there are so many variables involved. So the best thing parents can do is monitor RSV rates in their area and do what they can to protect their littles from these nasty winter germs.

Experts:

Dr. Rebekah Diamond, M.D., a hospital pediatrician in New York City, assistant professor at Columbia University, and the author of books Parent Like A Pediatrician and upcoming Eat Sleep Tantrum Repeat

Dr. Lori Handy, M.D., MSCE, attending physician in the Division of Infectious Diseases and the associate director of the Vaccine Education Center at CHOP (Children’s Hospital of Philadelphia)

Dr. Katie Lockwood, M.D., M.Ed., attending physician at CHOP (Children’s Hospital of Philadelphia) Primary Care Network in Flourtown, Pennsylvania

Dr. Roberto Posada, M.D., professor of pediatrics in the Division of Pediatric Infectious Diseases of the Jack and Lucy Clark Department of Pediatrics and the Mount Sinai Kravis Children’s Hospital

Dr. Priya Soni, M.D., a pediatric infectious disease specialist at Cedars-Sinai Guerin Children’s