Omicron Less Severe Than Delta for Children Aged Younger Than 5 Years

April 4, 2022

The incidence rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with Omicron variant was 6 to 8 times that of Delta variant in children aged younger than 5 years, but severe clinical outcomes were less frequent than with Delta variant, according to a study published in JAMA Pediatrics.

The study is the first large-scale research effort to compare the health outcomes of children aged younger than 5 years who were infected with the Omicron or Delta SARS-CoV-2 variants.

The severe clinical outcomes ranged from a 16% lower risk for emergency room visits to 85% less risk for mechanical ventilation. About 1.8% of children infected with Omicron were hospitalised, compared with 3.3% with Delta.

Pamela Davis, Case Western Reserve School of Medicine, Cleveland, Ohio, and colleagues analysed the electronic health records of more than 651,640 children in the United States who had a medical encounter with healthcare organisations between September 2021 and January 2022, including more than 22,772 children infected with Omicron in late December and late January and more than 66,000 children infected when Delta was prevalent in the fall. The study also compared the records of more than 10,000 children immediately before the detection of Omicron in the United States, but when Delta was still predominant. The team examined clinical health outcomes for paediatric patients during a 14-day window following SARS-CoV-2 infection, including emergency room visits, hospitalisations, intensive care unit admissions, and mechanical ventilation use.

Further demographic data analysis found that children infected with Omicron were on average younger and had fewer comorbidities.

“The major conclusion to our research was that many more children were infected with Omicron when compared with Delta, but the children who are infected are not impacted as severely as were children infected with the Delta variant,” said Dr. Davis. “However, because there are so many more children infected, our hospitals were affected over the winter months by an influx of young children.”


SOURCE: Case Western Reserve University