-
Viral shedding patterns of symptomatic SARS-CoV-2 infections by periods of variant predominance and vaccination status in Gyeonggi Province, Korea
-
Gawon Choi
 , Ah-Young Lim, Sojin Choi, Kunhee Park, Soon Young Lee, Jong-Hun Kim
-
Epidemiol Health. 2023;45:e2023008. Published online December 21, 2022
-
DOI: https://doi.org/10.4178/epih.e2023008
-
-
 Abstract
Summary
 PDF Supplementary Material
-
Abstract
OBJECTIVES
We compared the viral cycle threshold (Ct) values of infected patients to better understand viral kinetics by vaccination status during different periods of variant predominance in Gyeonggi Province, Korea.
METHODS We obtained case-specific data from the coronavirus disease 2019 (COVID-19) surveillance system, Gyeonggi in-depth epidemiological report system, and Health Insurance Review & Assessment Service from January 2020 to January 2022. We defined periods of variant predominance and explored Ct values by analyzing viral sequencing test results. Using a generalized additive model, we performed a nonlinear regression analysis to determine viral kinetics over time.
RESULTS Cases in the Delta variant’s period of predominance had higher viral shedding patterns than cases in other periods. The temporal change of viral shedding did not vary by vaccination status in the Omicron-predominant period, but viral shedding decreased in patients who had completed their third vaccination in the Delta-predominant period. During the Delta-predominant and Omicron-predominant periods, the time from symptom onset to peak viral shedding based on the E gene was approximately 2.4 days (95% confidence interval [CI], 2.2 to 2.5) and 2.1 days (95% CI, 2.0 to 2.1), respectively.
CONCLUSIONS In one-time tests conducted to diagnose COVID-19 in a large population, although no adjustment for individual characteristics was conducted, it was confirmed that viral shedding differed by the predominant strain and vaccination history. These results show the value of utilizing hundreds of thousands of test data produced at COVID-19 screening test centers.
-
Summary
Korean summary
코로나19 선별진료소에서는 확진 검사를 위해 수십만 건에서 수백만 건까지의 일회성 검사를 시행해왔다. 검사를 받은 개인의 특성과 관련된 데이터 제한으로 인해 분석 시 이를 보정할 수는 없지만, 대규모 인구집단에서 얻어진 검사 결과는 SARS-CoV-2 배출 특성을 평가하는 데 활용될 수 있다. 이번 연구에서는 바이러스 변이의 종류와 백신 접종 이력에 따라 증상 발생 후 시간 경과에 따라 바이러스 배출량이 달라지는 것을 확인하였다. 이러한 대규모 선별 검사자료는 향후에도 유용하게 활용 가능하다.
Key Message
The screening center for COVID-19 has conducted hundreds of thousands to millions of one-time confirmation tests for diagnosis. Although individual characteristics cannot be adjusted for due to data limitations, the test results from a large population can still be utilized to evaluate SARS-CoV-2 shedding. We confirmed that viral shedding varied over time after symptom onset, depending on the type of virus variant and vaccination history.
|
KSE
