COVID-19–related multisystem inflammatory syndrome in children (MIS-C) was milder amid the Omicron variant surge than during the Alpha and Delta waves in Israel, concludes a research letter published late last week in JAMA.Researchers from Rambam Health Care Campus in Haifa conducted prospectively studied all pediatric MIS-C patients at 12 Israeli hospitals during the same 16-week period in the Alpha (Dec 20, 2020, to Apr 10, 2021), Delta (Jul 18 to Nov 13, 2021), and Omicron (Nov 21, 2021, to Mar 12, 2022) pandemic waves.
Participating hospitals account for roughly 70% of pediatric intensive care unit (ICU) admissions in Israel.Of the 171 MIS-C patients, 59 (34.5%) were diagnosed during the Alpha wave, while 79 (46.2%) were identified during Delta, and 33 (19.3%) amid Omicron.
Median patient age was 8 years, and 55% were boys.Five of 79 patients (6.3%) in the Delta wave and 5 of 33 (15.1%) during Omicron had received a second COVID-19 vaccine dose at least 2 weeks before hospitalization. (Vaccination wasn't widely available in the Alpha wave.) No vaccinated patients required ICU care or treatment with vasopressors to raise their blood pressure.Better cardiac outcomes, fewer ICU staysCardiac outcomes were better during the Omicron wave, and there were fewer ICU admissions (7 [21.2%]) than during Delta (39 [49.4%]) and Alpha (34 [57.6%]).
Median hospital stay was also 2 days shorter amid Omicron than in previous waves.Fewer patients required vasopressors during the Omicron surge (6.0%) than in Alpha (22%) and Delta (17.7%).