Sensitivity of the Elecsys Anti-SARS-CoV-2 immunoassay as an aid in determining previous exposure to SARS-CoV-2
Authors: Hegel Johannes Kolja , Riester Elena , Rank Christopher M. , Langen Florina , Laengin Tina , Findeisen Peter 
Published: February 2021

Background

The Elecsys® Anti-SARS-CoV-2 electrochemiluminescence immunoassay (Roche Diagnostics International Ltd) was developed for the in vitro qualitative detection of antibodies to SARS-CoV-2. We evaluated the sensitivity of the Elecsys Anti-SARS-CoV-2 immunoassay in samples from a diverse cross-section of patients across multiple sites and compared results against commercially available comparators.

Methods

Sensitivity of the Elecsys Anti-SARS-CoV-2 immunoassay was evaluated using anonymised, frozen, residual single and sequential serum and plasma samples from patients with polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infection. Point estimates and 95% confidence intervals (CIs) were calculated and method comparisons performed versus the following comparator assays: Euroimmun Anti-SARS-CoV-2 IgG, Abbott ARCHITECT SARS-CoV-2 IgG, Siemens ADVIA Centaur SARS-CoV-2 Total, and YHLO iFlash SARS-CoV-2 IgG and IgM.

Results

Overall sensitivity for the Elecsys Anti-SARS-CoV-2 immunoassay in 219 samples drawn ≥14 days post-PCR confirmation was 93.6% (95% CI 89.5–96.5). Across the three study sites, sensitivity in samples drawn ≥14 days post-PCR confirmation ranged from 85.7–98.9%. Sensitivity was significantly higher for the Elecsys Anti-SARS-CoV-2 immunoassay compared with the YHLO iFlash SARS-CoV-2 IgM assay for samples drawn ≥14 days post-PCR confirmation (86.3% [95% CI 76.7–92.9] versus 33.8% [95% CI 23.6–45.2]). Both Siemens ADVIA Centaur SARS-CoV-2 Total and YHLO iFlash SARS-CoV-2 IgG assays had a significantly higher sensitivity compared with the Elecsys Anti-SARS-CoV-2 immunoassay for samples drawn ≥14 days post-PCR confirmation (95.1% [95% CI 87.8–98.6] versus 85.2% [95% CI 75.6–92.1]; 93.8% [95% CI 86.0–97.9] versus 86.3% [95% CI 76.7–92.9]). Differences in sensitivity between the Elecsys Anti-SARS-CoV-2 immunoassay and the Euroimmun Anti-SARS-CoV-2 IgG (90.3% [95% CI 83.7–94.9] versus 95.2% [95% CI 89.8–98.2]) and Abbott ARCHITECT SARS-CoV-2 IgG (84.8% [95% CI 75.0–91.9] versus 87.3% [95% CI 78.0–93.8]) assays for samples drawn ≥14 days post-PCR confirmation were not significant.

Conclusions

The Elecsys Anti-SARS-CoV-2 immunoassay demonstrated high sensitivity in samples collected ≥14 days post-PCR confirmation of SARS-CoV-2 infection, and comparable sensitivity to several commercially available comparator assays across multiple sites, supporting the use of this assay as a tool to aid in determination of previous exposure to SARS-CoV-2.

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Ethical guidelines

The study was conducted in accordance with the study protocol provided by Roche Diagnostics and in accordance with the principles of the Declaration of Helsinki. All human samples utilised at the three study sites in Germany (Augsburg, Heidelberg, Berlin) were anonymised, frozen, residual samples, therefore no ethical approval or waiver was required in accordance with local legislation from ZEKO (Central Ethics Commission at the German Medical Association). A statement was obtained from the Ethics Committee of the Landesärztekammer Bayern confirming that there are no objections to the coherent use of anonymised residual samples.

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Data availability statement

Qualified researchers may request access to individual patient level data through the clinical study data request platform (https://vivli.org/). Further details on Roche’s criteria for eligible studies are available here: https://vivli.org/members/ourmembers/. For further details on Roche’s Global Policy on the Sharing of Clinical Information and how to request access to related clinical study documents, see here: https://www.roche.com/research_and_development/who_we_are_how_we_work/clinical_trials/our_commitment_to_data_sharing.htm