Public schools are reopening in NYC, even as COVID-19 continues to spread, with new cases plateauing around 3,500 per day citywide, and more contagious variants starting to take hold.
Kids are much less likely to catch the virus, but some who do can face serious consequences in the form of Multisystem Inflammatory Syndrome in Children, or MIS-C. It’s a condition where different body organs can become inflamed, including the heart, lungs, brain, and skin.
Now a study from Northwell Health, the state’s largest health system, spots a worrying outcome for COVID-positive children and their kidneys. The researchers looked through the medical records of 152 pediatric patients with COVID-19, admitted from March to August at four New York-area hospitals. About one out of 10 kids with COVID-19 had acute kidney injuries. The proportion doubled for those who also developed MIS-C. Severe kidney dysfunction in children is typically very rare—on the order of one to two dozen cases per 100,000 children in developed countries.
Dr. Christine Sethna is an associate professor at Northwell’s Feinstein Institutes for Medical Research and one of the study’s co-authors. She spoke with WNYC’s David Furst about their findings, how parents can spot MIS-C, and when kids might be eligible for COVID-19 vaccines. The interview was lightly edited for clarity.
Can you briefly describe for us how MIS-C works? How long does it take to appear after a child catches COVID? And how does it affect the body?
We don’t know the exact reason or mechanism, exactly how it occurs. But we know that it is a post-viral syndrome, meaning that we believe that it is associated with having had a previous COVID infection. It usually presents six to eight weeks after that infection.
What did your study find in terms of MIS-C and kidney injury? How often do you see this?
So we studied the incidence of acute kidney injury, which is defined as the abrupt cessation of kidney function. And we looked at 152 children admitted to our four hospitals within the Northwell Health system, with both the acute COVID-19 infection and MIS-C. And we found in the total cohort we had that 11.2% had this acute kidney injury. Specifically, of the 55 children with the MIS-C, the incidence was slightly higher; it was about 18.2%.
Overall, children being hospitalized with COVID and MIS-C is very rare, and in addition, it’s still rare to have a kidney injury. But we want to let the public and the medical profession know that this is a complication of COVID.
Luckily, the majority of the children who had acute kidney injury did resolve. We did have a couple that needed dialysis to help the kidney clear the waste from the body. But the majority did resolve. Only two children left the hospital with still some residual kidney issues.
The CDC says New York City and New York State have reported between 150 to 250 cases of MIS-C in childrenn. How worried should parents be?
So still, overall, COVID-19 infection is happening at much lower rates in children compared to adults. And of the proportion with COVID infection, the rate of MIS-C is even much rarer. So nationwide, there are over 2,000 cases. So it is it’s extremely rare, but parents should still be aware.
What should parents watch out for?
About six to eight weeks after a known COVID infection, if they have signs of vomiting, diarrhea, high fevers, skin symptoms, or lethargy, they should seek medical attention.
What is the latest on the COVID-19 vaccine trials in kids? How long before they can get the vaccine and before they are vaccinated in large numbers?
Right. So the Pfizer vaccine is already approved for ages 16 and up, but they are not available yet from the state to get the vaccine, except if you have a medical condition right now. But when that opens up, the Pfizer vaccine will be eligible for 16 and up.
Both Pfizer and Moderna have completed enrollment in their clinical trials for children ages 12 to 15 and up to 18 for Moderna. And so we’re expecting those results probably in late spring, early summer.
So best-case scenario, I would say summertime for the 12 to 15 age group to late fall for them. The next stage is the children below age 12. They have not yet started enrollment in that group. So that’s going to be much later, probably late in the year or even early 2022.