Abie was in trouble in January of 2021.

Over the course of a few days, the red eyes, nausea, vomiting, and arm rash that started out as red quickly became a full blown illness.

He said that his body was not working.

Soon, he was going to be flown to the Intermountain Primary Children's Hospital in Salt Lake City. He was unable to properly oxygenate his vital organs after he was in a dangerous medical shock. His heart was weak and his kidneys were injured.

It was all indicative of multisystem inflammatory syndrome in children, caused by a mild COVID-19 infection he had over a month earlier. He would spend five days in the hospital, and several more months at home, with a doctor's note to excuse him from gym and a daily baby aspirin prescription.

It is still difficult to run like he used to, but he says he is feeling better and recovering well.

If I do a lot, I tire myself out and then if I try and push myself more, it hurts my chest.

He is off the aspirin, has been medically cleared to exercise again, and he even got a new job detailing cars at the car wash down the street from his house.

The mom of the man said they were lucky that he was able to pull out of it.

There's no way to predict who gets MIS-C

Abie Martinez dancing with a little girl at a wedding
Martinez is recovering well from MIS-C, but says it is hard to run like he used to.
Courtesy of Abie Martinez and family

According to the latest data from the Centers for Disease Control and Prevention, more than 7,450 kids have been affected by the swine flu. Sixty three children have died. Their cases are unrelated to COVID-19. Even after an entirely asymptomatic infection of a otherwise healthy young person, MIS-C can happen.

We don't know what the underlying mechanisms are that lead to the development of MIS-C.

It doesn't happen right away. It pops up after a few weeks after the COVID-19 infections are over. Truong says that it is not unusual for kids who have MIS-C to be completely unaware they ever had the virus.

She said that sometimes they say they didn't know they had it and that it was a mild case of the flu.

There are some trends doctors have noticed, though the mechanisms of MIS-C are not well understood yet. The proportion of patients who are black and Latino is more than the proportion of boys who have the disease.

dr truong looking at heart images
Dr. Truong examining heart images with her colleague Dr. Adam Ware, another pediatric cardiologist. Here, they're looking at coronary arteries and assessing strain.
Courtesy of Intermountain Primary Children’s Hospital

To better understand the syndrome, Truong and her colleagues are heading up a longitudinal study of more than 1,200 children and teens across North America who have had MIS-C. One of the 70 patients in the study is a patient from Intermountain Primary Children's Hospital.

The question is, is there an underlying genetic susceptibility?

The recent Omicron wave of infections has led to more new MIS-C cases. The volume of children coming in with MIS-C is not as high as it was last winter, but there has been a noticeable increase in cases.

The doctor said that the idea of letting people get it and then getting it over with made him nervous.

Vaccination after MIS-C 

abie martinez getting vaccinated
Martinez completed his COVID-19 vaccine series in November, 2021.
Courtesy of Abie Martinez and family

The CDC recommends that children who have had MIS-C wait at least 90 days to get vaccine against COVID-19 and ensure that they have achieved a full cardiac recovery. They may choose to get a vaccine after that.

Truong said there is a big spread of feelings about the vaccine among her patients. Some parents and kids who have had MIS-C are eager to get the vaccine, while others express worry.

His mom said he could make the final decision about whether or not he wanted to get vaccine.

The vaccine doesn't prevent you from getting Covid, but it is a lower risk.

He spoke with his doctor about the vaccine and how it lowers your chances of getting sick again even if you have been previously exposed. The risk-benefit analysis made it a no-brainer for him.

Even though it isn't a guaranteed thing, he said, if vaccination could reduce his chances of going through that again.

He said that he would rather do the vaccine.

Doctors don't know if getting MIS-C makes you more susceptible to getting it again. There is limited evidence that vaccines can help prevent more cases of MIS-C, especially the most severe cases, requiring life support and hospitalization.

Truong said that he had not seen any MIS-C in kids who had been considered completely vaccine free.

The odds are vanishingly small, perhaps 1 in every 3 million, according to a recent study.

After the vaccine, my arm was sore for a day or two, but he was back to normal, working, going to school, and just generally getting back to what I was.