The study findings showed that most SARS-CoV-2 reinfection cases occurred due to Omicron. Omicron reinfections among those with primary Omicron infection happened within a short period, as less as three weeks. The findings indicated that primary infections with non-Omicron VOCs were inadequate in providing immune protection to prevent reinfections with Omicron.
Further, the findings highlight the transmissibility and immune-evasiveness of Omicron and the need for updated SARS-CoV-2 vaccines, continued SARS-CoV-2 surveillance, and SARS-CoV-2 evolutionary assessments to guide policy-making for improved public health across the globe. In addition, the analysis underscores the need for analyzing individual-level NGS data to provide precise estimates of SARS-CoV-2 reinfection risks.