Severity of SARS-CoV-2 Reinfection Similar to That of Initial Infection: Daily Dose

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On July 15, 2024, we reported on findings from a study published in Communications Medicine that compared the severity of SARS-CoV-2 reinfection with initial infection.

The study

Investigators analyzed electronic health data of 3.1 million participants in the National COVID Cohort Collaborative (N3C) to calculate summary statistics, effect sizes, and Kaplan-Meirer curves. A total of 212 984 participants (mean age, 45 years; 66.4% women) reported an initial SARS-CoV-2 infection between March 1, 2020, and December 31, 2022, and a second infection by March 2023, and were enrolled in the current study. A COVID-19 reinfection was defined as a positive SARS-CoV-2 polymerase chain reaction or antigen test 60 or more days after a COVID-19 infection index date.

The findings

Results showed a statistically significant association of severity between initial infection and reinfection (chi-squared value: 25 697; P < .0001) with a medium effect size (Cramer’s V: 0.20, DoF = 3).

Authors' comment

"Our work highlights the prevalence and impact of reinfections and suggests the need for further research."

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