Some blame the ‘tripledemic’ on ‘immunity debt,’ but experts demur
This fall and winter, many hospitals across the country were overwhelmed with an unusually high number of patients suffering from respiratory diseases – mainly respiratory syncytial virus (RSV), flu and COVID-19. Some blame this surge on “immunity debt.”
Across the US, hospitals have reached capacity and have had to make room for patient overflow in hallways, offices, and even tents in parking lots. The situation, dubbed the “triple disease,” has also led to a partial shortage of certain antibiotics and antipyretic drugs for children, such as paracetamol and ibuprofen of the country.
Some of what is This is not entirely surprising as most viral respiratory infections follow seasonal patterns and are more prevalent during the winter months. However, the doctors have said what is been unusual this year is how early some of these viruses peaked.
RSV, which typically begins to circulate at higher levels in winter, began in late summer and continued through fall. Flu season also started about a month earlier, and flu-related hospitalizations were at their highest level in a decade nationwide, according to the Centers for Disease Control and Prevention.
In addition to the overwhelming number of patients, some doctors have said that RSV cases have also been more severe.
What is immunity debt?
Although the underlying reasons behind these viruses’ convergence and surge in infections this year are unclear, a popular idea that has emerged to explain what’s causing the triple pandemic is a concept called “immunity debt.”
According to this theory, people have been less exposed to the virus over the past two years due to COVID-19 containment measures such as masking, isolation and social distancing. Because these infection prevention techniques also target other respiratory viruses (such as Influenza and RSV) from spreading, the number of infections they cause has fallen sharply while such measures have been in place. But now that most of the COVID-19 restrictions are gone and society has reopened, these respiratory viruses are making a comeback and making more people ill.
“I think there is a general consensus that this is part of what is going on, that how these mitigation measures have helped prevent the spread in the past and now we don’t have them. So it’s not surprising that we’re seeing this rapid increase in these other viruses as well,” Jane Thomason, an industrial hygienist at National Nurses United (NNU), the largest organization of registered nurses in the United States, told Yahoo News.
However, the concept of “immunity debt” is controversial because it is has also been used to suggest that lack of exposure to viruses due to pandemic restrictions may have weakened people’s immune systems, especially children’s.
The idea of ”immunity Debt” first appeared in a 2021 opinion paper published by a French pediatric group in Infectious Diseases Now. The authors warned that while measures to contain COVID-19 are important to prevent hospitals from being overwhelmed, these precautionary measures also make people’s immune systems less effective at fighting pathogens due to a “lack of immune stimulation.” become.
Since the paper was published, the term has been the subject of much discussion social media, in news agencies and in medical journals. Like many other aspects of the COVID-19 pandemic, “immunity debt,” a scientific concept, has been heavily politicized, with opponents of masking using the theory to prove their belief in masks did more harm than good.
Our immune system never stops working
Catherine Troisi, an infectious disease epidemiologist at the University of Texas School of Public Health in Houston, told Yahoo News it’s wrong to assume that mitigation measures that prevented the spread of COVID-19 and saved “hundreds of thousands of lives” caused harm have immune systems of the children.
“It shows a lack of understanding of how our immune system works,” Troisi said. “When I was a kid and exposed to measles, my body made these memory T cells [an important part of the immune system that helps us fight some viruses]. These cells stay for the rest of your life, and should I come into contact with the measles virus, they will spring into action and create more cells that can fight the virus. … So the idea that we haven’t been exposed to the flu for two years and now there’s something wrong with our immune system – that’s just not how immunity works.”
Additionally, Troisi explained that our immune system is constantly working, even without contact with pathogens. “There are many, many things that we are not constantly exposed to. And yet, should we be exposed, our bodies and immune systems kick in and we’re protected,” she said.
NNU President Deborah Burger said she had never heard of “immunity debt” in the more than 45 years she’s been a nurse. She told Yahoo News it’s worrying that the term is gaining traction because it’s “highly misleading” and dangerous because it suggests people need to constantly expose themselves to pathogens in order for their immune systems to remain robust.
Last month, the organization slammed those who blamed the rise in pediatric RSV infections and associated hospitalizations on the “immune debt” theory.
In a In a statement, NNU called a CDC expert who said during a media briefing in November that children “need to get infected to move forward” because RSV is “very common” in children.
This statement, Burger said, is problematic because it could easily be misinterpreted by some parents, who might be led to believe that they need to intentionally expose their children to RSV.
“It’s like the old days when I was growing up and there were these ‘chickenpox parties,’ right? Oh, and they say, “Oh, come and expose your child to chickenpox.” But it can be deadly. They did it for measles, mumps and all that stuff, but people still died from it. It doesn’t make sense,” she added.
Troisi explained that most children encounter RSV at some point in their first year and a half and develop antibodies that later protect them from future infections. Although the immunity provided by an RSV doesn’t last very long, enough of it usually remains to mitigate subsequent infections, she said.
There are currently no vaccines available for RSV, but some vaccine manufacturers are working to develop one.
What could be the reason for the children’s “triple disease”?
One possible reason there were so many sick children with RSV in 2022 is that over the past year, many children have not yet attended school in person and have not been exposed to the virus. “They didn’t have a chance to build up antibodies,” Troisi said. She explained that babies’ immune systems aren’t very strong at birth and nature protects them with antibodies passed from their mother to them, which are passed to the baby through the placenta and breast milk.
“Around six months after birth, babies are protected by their mother’s antibodies. So again, because the mothers weren’t exposed [during the pandemic]her antibody levels might have been a bit lower,” she said, adding that “it had nothing to do with her immune system.”
However, other experts have argued that the summer of 2021 also saw a surge in RSV infections after some pandemic restrictions were eased, and many children should have gained some immunity to these infections that would have protected them that year. Therefore, the idea of ”immune debt” does not yet fully explain the sharp increase and severity of RSV infections this year.
Troisi said health experts are still trying to understand what caused these viruses to converge and why so many people got sick at the same time.
Thomason said one possible reason children’s hospitals are overwhelmed is a lack of beds. She told Yahoo News that from 2008 to 2018, the hospital industry cut about 19% of children’s hospitals nationwide.
Another idea floating around is that this is another result of COVID.
“COVID has long-lasting effects on people’s immune systems,” Thomason said. “By April 2022, at least 75% of children had at least one COVID infection and more than 60% of the general population had at least one COVID infection. That’s a lot of people with potentially long-lasting immune system dysfunction, putting them at higher risk of contracting RSV and influenza when exposed to these other viruses, and at greater risk of serious illness.”
But Troisi said there just isn’t enough evidence to prove this theory so far. She noted that there is a lot of evidence that measles infection can affect a person’s immune system, but this has not yet been proven with COVID.
“I think the jury is out now. There is no good evidence that it happens. But you know, we changed our minds as we learned more about this virus,” Troisi said. “I’m certainly not saying with certainty that SARS-CoV-2 doesn’t affect your immune system after infection, but at the moment we don’t have evidence of that.”