Osong Public Health Res Perspect.  2023 Aug;14(4):272-278. 10.24171/j.phrp.2023.0024.

Increased viral load in patients infected with severe acute respiratory syndrome coronavirus 2 Omicron variant in the Republic of Korea

• Kim JM
• Kim D
• Lee NJ
• Woo SH
• Lee J
• Lee H
• Park AK
• Kim JA
• Lee CY
• Kim IH
• Yoo CK
• Kim EJ

• KMID: 2545872
• DOI: http://doi.org/10.24171/j.phrp.2023.0024

Abstract

Objectives
Coronavirus disease 2019 (COVID-19) has been declared a global pandemic owing to the rapid spread of the causative agent, severe acute respiratory syndrome coronavirus 2. Its Delta and Omicron variants are more transmissible and pathogenic than other variants. Some debates have emerged on the mechanism of variants of concern. In the COVID-19 wave that began in December 2021, the Omicron variant, first reported in South Africa, became identifiable in most cases globally. The aim of this study was to provide data to inform effective responses to the transmission of the Omicron variant.
Methods
The Delta variant and the spike protein D614G mutant were compared with the Omicron variant. Viral loads from 5 days after symptom onset were compared using epidemiological data collected at the time of diagnosis.
Results
The Omicron variant exhibited a higher viral load than other variants, resulting in greater transmissibility within 5 days of symptom onset.
Conclusion
Future research should focus on vaccine efficacy against the Omicron variant and compare trends in disease severity associated with its high viral load.

Keyword

Omicron variant; SARS-CoV-2; Transmissibility