Age significantly influences the sensitivity of SARS-CoV-2 rapid antibody assays

Abstract

BACKGROUNDPoint of care serological assays are a promising tool in COVID-19 diagnostics but do have limitations. This study evaluated the sensitivity of five rapid antibody assays and explored factors influencing their sensitivity to detect SARS-CoV-2-specific IgG and IgM antibodies.METHODSFinger-prick blood samples from 102 participants, within two to six weeks of PCR-confirmed COVID-19 diagnosis, were tested for IgG and IgM on five rapid serological assays. The assay sensitivities were compared, and patient factors evaluated in order to investigate potential associations with assay sensitivity.RESULTSSensitivity ranged from 36% to 69% for IgG and 13% to 67% for IgM. Age was the only factor significantly influencing the likelihood of a detectable IgG or IgM response. Individuals aged 40 years and older had an increased likelihood of a detectable IgG or IgM antibody response by rapid antibody assay.CONCLUSIONRapid serological assays demonstrate significant variability when used in a real-world clinical context. There may be limitations in their use for COVID-19 diagnosis amongst the young.

Serology assays used in SARS-CoV-2 seroprevalence surveys worldwide: a systematic review and meta-analysis of assay features, testing algorithms, and performance

“…Moreover, viral mutations may result in decreased assay performance [30] . Additionally, studies have shown differences in antibody dynamics in specific populations such as those from sub-Saharan Africa, young adults, and pregnant women that may impact test performance [31–34] . Independent evaluations targeted toward the intended study population using representative panels are strongly supported by our findings which reach an updated understanding of serological assay performance, and conversely, accurate seroprevalence estimates.…”

“…Moreover, viral mutations may result in decreased assay performance [30] . Additionally, studies have shown differences in antibody dynamics in specific populations such as those from sub-Saharan Africa, young adults, and pregnant women that may impact test performance [31–34] . This step is not always feasible for all research settings, as we found only a small proportion (6.9%) of independent author groups conducted their own assay pre-study validation before rolling out their serosurvey.…”

Development of a new antigen-based microarray platform for screening and detection of human IgG antibodies against SARS-CoV-2

“…For ELISA as well as for LF-tests, the choice of the test antigen is particularly important 12 especially given the high rate of mutation and variation of the virus and its antigens. Selection of test antigens can affect the test performance and is one reason, among others, why the performance of the various lateral flow tests and ELISA varies considerably between different sample cohorts and different commercial tests 13 .…”