The Associated Factors of SARS-CoV-2 Reinfection by Omicron Variant — Guangdong Province, China, December 2022 to January 2023

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC? Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection by variants is being reported commonly and has caused waves of epidemic in many countries. Because of dynamic zero policy, the SARS-CoV-2 reinfection was less reported in China. WHAT IS ADDED BY THIS REPORT? SARS-CoV-2 reinfections were observed in Guangdong Province between December 2022 and January 2023. This study estimated that the reinfection incidence was 50.0% for the original strain primary infections, 35.2% for the Alpha or Delta variants, and 18.4% for the Omicron variant; The reinfection incidence within 3-6 months after primary infection by Omicron variant was 4.0%. Besides, 96.2% reinfection cases were symptomatic while only 7.7% sought medical attention. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE? These findings suggest a reduced likelihood of an Omicron-driven epidemic resurgence in the short term but emphasize the importance of maintaining vigilant surveillance of emerging SARS-CoV-2 variants and conducting population-based antibody level surveys to inform response preparedness.