I started this blog as a means of combating pandemic disinformation, and it's obviously focused a lot on COVID-19. I've dabbled with other viruses - influenza and HPV, specifically. One that I have not yet touched on, because we had a welcome respite from it during the pandemic, is respiratory syncytial virus - RSV. Unfortunately, the topic has become quite relevant again as RSV, in the worst way, sweeps the nation. This will be a short summary - The brilliant Edward Nirenberg has written extensively about this, which I'll link to below.
IS THIS A NEW VIRUS?
No. RSV has been around for quite a while (since the 1950s!). If you have had young children in the last ten years, you are likely aware of RSV. It is actually a problem in older adults as well, and it is one of three viruses you will likely be tested for if you go to the emergency department with upper respiratory symptoms (the other two being SARS-CoV-2 and influenza).
RSV is usually seasonal, similar to influenza and rhinovirus (the common cold), and like those viruses and COVID-19, it can cause a range of illness from mild cold-like symptoms to a severe lands-you-in-the-hospital-on-oxygen infection. Repeat infections are possible, though first-time infections (especially in babies) are usually the hardest. Most infections are on the milder side, but hospitals (both adult and pediatric) are surging right now. Pediatric hospitals especially are overwhelmed, similar to mid-2020 when adult hospitals faced the initial onslaught of COVID-19 and we needed to literally build new hospital wings. Except kids aren't getting that luxury with the staff shortages we face, and people refuse to change behaviors to try and reduce cases.
YOU'VE HARPED ON COVID AND INFLUENZA FOR MULTIPLE YEARS NOW. WHY HAVE WE NOT HEARD ABOUT THIS?
Remember how many times I have had to reiterate that masks work against COVID, even though they aren't perfect? Turns out they work even better against RSV and influenza! We saw blissfully low numbers of RSV and influenza (and yes, we did test for them) when everyone was masking and staying home/away from work when sick because those non-pharmaceutical measures WORKED! I remember feeling relieved at how little flu and RSV I saw in 2020 (even as I had to watch so many people suffer and die from COVID) as we finally caught up with other parts of the world in terms of simple measures to help each other. Those days are long gone now, it seems. With the dropping of mask mandates and shortening/cancelling of time away from work for sickness, we saw a summer surge of RSV and now we are smack dab in a winter surge.
WHY IS RSV SURGING? IS IT IMMUNITY DEBT?
The reason RSV is usually mild is because it usually circulates so much that our immune systems identify it and fight back (immunological memory), BUT not enough to prevent infection entirely (just like with COVID, infection-mediated immunity is not reliable and does not last). Infants don't have the immune system to do this - their immunity comes from maternal antibodies, which come from maternal infections, which - similar to COVID - are not recommended as a way to obtain immunity. Masks and other measures meant fewer RSV infections, which mean less maternal antibodies passed on to infants in the last two years, and less antibodies in general, which led to the current surge once those measures were dropped. That is NOT immunity debt, because immunity debt is not actually a thing.
This is an example of how fast disinformation spreads. Jonathan Jarry discusses how the phrase and concept of "immunity debt" only came about after COVID hit our shores (try searching for it among scientific literature). He also points out how in the past, exposures have been staggered so kids hit the hospital at different times but this year, everyone is getting exposed rather rapidly (their first infection with RSV) and the wave is hitting us hard.
From RSV-NET. The olive line with dots represents the current RSV season, and how fast we peaked in hospitalizations. There is significant concern that we will have a consistently high rate this season, if we do not take precautions and employ countermeasures.
This graph is Canadian, but it's similar to how things are going in the USA.
BUT DON'T KIDS NEED TO GET SICK TO BUILD THEIR IMMUNITY?
So here's the thing - there is a fundamental misunderstanding of the "hygiene hypothesis," and not just among anti-vaxxers (although they drive the myths). People (especially kids) DO NOT NEED TO BE INFECTED WITH DISEASES to "build their immunity." The hygiene hypothesis is not about pathogens. The experiments were done on rats in completely sterile (like, HAZMAT suit-style clean rooms) environments, meaning they were not exposed to even the benign bacteria and dust particles that we encounter every day. THAT exposure helps build immunity. That is why it's good that kids play outside in the dirt, and ALSO FINE that you sanitize their hands afterward.
That misunderstanding is why so many people argued against masks and other mitigation measures, claiming we needed exposure in order to build immunity - there is no evidence for that, and as I have said, infection is not a good way to form immunity because of the risk involved. Nirenberg's blog post discusses historical context for why these misunderstandings have occurred.
IS THERE A VACCINE?
Not yet, but soon! Both Pfizer and Glaxo-Smith-Kline have announced vaccines for adults, which means vaccines for children are not far behind. This is how to develop immunity safely in those most vulnerable.
WHAT DO I DO IF MY KID OR I GET RSV?
Talk to your doctor! Similarly to COVID, not every bout of upper respiratory symptoms requires a trip to the Emergency Department, but if the child or adult develops difficulty breathing or other severe symptoms (like if they are difficult to arouse or if bodily functions have been drastically reduced or have stopped) that may merit a trip or at least a discussion. Frankly, if your parental alarm bells are going off, it is understandable to talk to the pediatrician/family doctor if you have one, or to visit the ED or urgent care.
TRIPLE-DEMIC
There's another new phrase that is now making its way around the Internet, and it has more evidence and theory behind it than "immunity debt." It is "triple-demic."
As we enter this winter, we face not only the ongoing RSV surge, but also influenza and the still-present-despite-politicians'-claims COVID-19. Exposure and infection to one, especially if you happen to get severe infection, leaves you more vulnerable to the other two.
There is no vaccine against RSV yet, so it remains vitally important that you get your vaccine against influenza, and your original series and/or bivalent booster against COVID-19, and to do it now so you have time to build that vaccine-mediated immunity before Thanksgiving and other gathering holidays. The past two years have also shown us how effective non-pharmaceutical interventions (like masks indoors) have helped protect us from these infections - so we should continue to use them (or, you know, go back to using them)!
Get vaccinated (against COVID and influenza), wash your hands, wear a mask, and let's look out for each other as we have fun with friends and family this winter! As always, I welcome your questions.
Jonathan Jarry's article on "immunity debt": https://www.mcgill.ca/oss/article/covid-19-medical-critical-thinking/claims-immunity-debt-children-owe-us-evidence
Edward Nirenberg's much more in-depth article on RSV, including history, biochemistry, pathophysiology, and treatments and vaccine developments: https://www.deplatformdisease.com/blog/rsv