SARS-CoV-2 reinfection with different SARS-CoV-2 variants in children, Ohio, US.

BACKGROUND: Beginning in late 2021 we observed a significant increase in SARS-CoV-2 reinfections in pediatric patients evaluated at our institution. We aimed to characterize the children with SARS-CoV-2 reinfection, to determine the number of SARS-CoV-2 reinfections and characterize the intervals between two infections in our patient population.

METHODS: From March 2020 to September 2022, we identified children ≤ 21 years old who had ≥2 SARS-CoV-2 infections using laboratory reports. We then defined the type of SARS-CoV-2 variant in the first and subsequent infections by mutation specific typing or local epidemiology data. Clinical outcomes and interval between SARS-CoV-2 infections were assessed.

RESULTS: We identified 541 children with ≥ 2 SARS-CoV-2 infections. The median interval between two infections was 229 days. The hospitalization rate was lower in the second infection. Reinfection counts were higher during the periods that Omicron variants predominated. Reinfection occurred more rapidly when Omicron variants were circulating with some occurring in less than 90 days.

CONCLUSION: As SARS-CoV-2 continues to evolve, there is a need for ongoing surveillance to identify the frequency and time interval between reinfections and to re-evaluate the definition of SARS-CoV-2 reinfections.