Is immunity debt or immunity theft to blame for children's respiratory virus spike?
During what, for many, is a week full of gatherings leading up to New Year's Eve celebrations, the Centers for Disease Control and Prevention has warned of a rise in severe Strep Group A infections among children. This is in the midst of an active respiratory virus season that has put pediatric hospitals under intense pressure.
Kids seem to be catching everything and getting sicker as the pandemic enters its third winter, leaving physicians and researchers to figure out what's going on.
At first, some people theorized that the tools used to protect against COVID-19, like isolation and masking, had left children vulnerable to other infections. The theory is called immunity debt, and it suggests that because children's immune systems hadn't been challenged by viruses like respiratory syncytial virus — RSV — while taking protective measures against COVID, they had become more susceptible to infection.
However, the immunity debt theory doesn’t seem to hold up to scrutiny. Dr. Tess Barton, UT Health San Antonio associate professor of pediatric infectious diseases, understands where the idea came from.
“The nugget of truth in there is that we do build immunity over time with repeated exposures to things," Barton said. "So, getting exposed to things does help us to build up our immune system.”
But this is the second real RSV season we’ve had during the pandemic, with a big surge during the summer of 2021, Barton said.
“That was sort of the great unmasking, and everybody got viral illnesses," she said. "Now we're past that. We've already been through that. We should have some immunity from that, and we're having it again.”
Barton also pointed out that many of the people getting sick this fall weren't even born when people were taking precautions against COVID infection.
"The hospital is filled with babies who are less than a year of age who have RSV infection. Those children weren't locked down in 2020," Barton said.
The theory of immunity debt also suggests that most Americans took pandemic precautions seriously and were essentially locked down for a long time. That simply didn't happen. Also, if a debt was incurred, it would seem that states in which precautions were never mandated would have fewer viral infections now. Barton said that's not the case.
"We're not seeing [less viral illness in] states in the United States that were less strict compared to states that were more strict during mask mandates and things like that. All the states are being impacted," Barton said.
Many experts suggest what is actually occurring is what some are calling immunity theft.
“The concept is that you have this temporary immunodeficiency that happens after you get an infection.”
Research has found that having COVID — even a mild case — can interfere with a person's immune function for at least eight months, leaving them vulnerable. Barton is seeing children this year who get a viral infection, usually COVID, then get something else soon after.
“It's just like boom, boom, boom — one infection after another. I can't tell you how many kids I've already I've seen who've had COVID and strep, one right after the other. COVID and Epstein-Barr virus, one right after the other. COVID and hand, foot, mouth, one right after the other.”
And strep this year has become a real concern. The CDC warning about the rise in cases of invasive strep group A in the United States follows at least two dozen strep group A deaths in the last four months among children in England. Barton pointed out that strep group A is known for sometimes causing an overwhelming immune response.
“Most people who get Group A strep infections have a miserable sore throat for a few days, and your immune system will take care of it. And if you get some antibiotics, you'll get over it a little bit quicker, and then you go on about your business," Barton said. "The challenges with group A strep is that it's a bacteria that elicits a pretty strong immune response. And some strains of group A strep actually produce toxins. The bacteria itself makes a little poison that causes a massive immune response.”
Strep is a bacterial infection, and having a viral respiratory infection, like COVID, or flu or RSV, can make a person more vulnerable to bacterial infection. Barton said with that in mind, the goal — still — should be to avoid getting sick in the first place. Parents should get children vaccinated against the flu, get the COVID bivalant vaccine, avoid sick people and wear masks when gathering indoors.
Adults and children who are sick should stay home and avoid holiday gatherings to protect others.