About 618 million confirmed cases of the 2019 coronavirus disease (COVID-19) had been found as of October 2022. There is a chance of reinfection, which would have serious clinical repercussions for survivors. Researchers recently discovered that seropositivity was associated with a lower risk of future infection over a median time span of 54 days in an analysis of a national US cohort.

The ratio of positive nucleic acid amplification test (NAAT) results between index SARS-CoV-2 positive persons and index negative persons over 90 days after a positive index SARS-CoV-2 antibody test was found to be 0.1, indicating that prior infection elicited roughly 90% protection against reinfection.

In the present study, researchers explored the duration of SARS-CoV-2 infection’s protective effect against reinfection. The study population comprised 144,678,382 persons gathered from US real word data (US RWD) sources vetted by HealthVerity, and medical service data obtained between February 2, 2020, and April 30, 2021.

This dataset combined distinct record sources from commercial laboratory databases, pharmacy databases, medical claims databases, hospital chargemasters, and outpatient electronic health records (EHR). The collection contains information for people who had a SARS-CoV-2 antibody test or index NAAT between February 29, 2020, when NAAT testing, and December 9, 2020, before COVID-19 vaccines were introduced.

The primary study outcome involved the identification of a group of SARS-CoV-2-tested persons. Individuals were included based on their initial NAAT or SARS-CoV-2 antibody test results. Eligible individuals were required to report 12 months of continuous closed medical enrollment, EHR, and claims activity before the index date.