Seroprevalence of SARS-CoV-2 antibodies during the third wave of COVID-19 in the Seoul metropolitan area of Korea

Abstract

Ethics approvalThis study was approved by the institutional review board (IRB No. P01-202102-31-002, SMF-IRB-2021-003).

Realistic Estimation of COVID-19 Infection by Seroprevalence Surveillance of SARS-CoV-2 Antibodies: An Experience From Korea Metropolitan Area From January to May 2022

“…Although the discrepancy between the estimated seroprevalence and the cumulative incidence might be influenced by intrinsic factors such as sampling issues, differences in the definition of the two parameters, and duration of antibody retention, it is plausible that the discrepancy represents a population of concealed infection cases, mainly due to asymptomatic individuals who were not subject to the test-trace-isolate-quarantine strategy of KDCA to control the spread of infection. Yoon et al, 11 who conducted a relatively large seroprevalence study, suggested that the infection control strategy of RT-PCR screening seemed to be effective and the rate of undetected cases was low; however, it was performed from January to March 2021, which was before the active spread of the delta and omicron variants in Korea ( Fig. 6B ).…”

“…Between late 2020 and early 2021, less than 1.0% was seropositive in approximately 5,000 individuals across major cities in South Korea according to the serosurveys conducted on health examinees. 10 11 12 Between September and December of 2020, overall seroprevalence was 0.39% among 4085 subjects. 12 Between April and December 2020, 0.09% was seropositive among 5,284 subjects.…”

“… 10 Between January and March 2021, it was 0.55% in women and 0.38% in men among 4,942 subjects. 11 However, these studies were conducted when the pandemic was still in its early stages and did not take into account the distribution of the general population. Moreover, they were conducted before the initiation of a nationwide vaccination targeting the general population, highlighting the need for population-based serosurveys after the implementation of the vaccination program.…”

Korea Seroprevalence Study of Monitoring of SARS-COV-2 Antibody Retention and Transmission (K-Sero SMART): findings from national representative sample

“…However, in late 2020, the third peak of COVID-19 occurred. From then onward, the proportion of cases with epidemiologic transmission routes unknown at the time of diagnosis increased, resulting in many unreported cases within the community [ 4 ]. These cases have been reported to account for 5% to 80% of individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a systematic review and meta-analysis worldwide [ 5 ], who shed the virus at similar levels comparable to symptomatic individuals [ 6 , 7 ].…”

“…Furthermore, these surveys did not provide analysis by region, age, or other socio-demographic factors. The use of residual sample from other survey systems has been limited in calculating a representative prevalence of antibodies to SARS-CoV-2 [ 4 , 12 , 19 , 20 ]. The prevalence of antibodies to SARS-CoV-2 may vary based on factors such as the survey population, sampling method, timing and location of the survey, and blood sample analysis technique employed [ 11 ].…”