Antibody LFA Evaluation
In March 2020, the Mass General and Brigham Center for COVID Innovation (MGBCCI) established the Diagnostics Pillar and several associated Working Groups. The goal of these Working Groups was to identify and evaluate the variety of devices and platforms proposed to diagnose or characterize SARS-CoV-2 infection and response to COVID-19. The Direct to Consumer Working Group focused on technologies meant for non-laboratory use, i.e. marketed directly to consumers and used without involving healthcare providers. These included serological lateral flow assays (LFA), which detect antibodies (IgG and IgM) against SARS-CoV-2, consistent with prior exposure to the virus.
The MGBCCI Diagnostics Accelerator working group embarked on a study evaluating approximately 20 of these LFAs. When tested, these assays were in different stages of approval by the Food and Drug Administration (FDA), which has been granting Emergency Use Authorization (EUA) for those that pass strict FDA evaluation criteria (FDA EUA status of these assays can be found here).
We are reporting MGBCCI data based on standardized laboratory evaluations performed on biobanked plasma samples from confirmed SARS-CoV2-infected patients (based on gold-standard molecular tests) and SARS-CoV2-negative samples collected before the pandemic. The testing evaluated the performance of LFAs in a high complexity laboratory setting and can provide no information on consumer use or suitability as a direct to consumer product. The testing of the LFAs is intended for MGBCCI evaluation purposes only. The MGBCCI, associated individuals or institutions, do not endorse any of these products.
One of the goals of the MGB CCI Diagnostics Accelerator is to evaluate COVID-19 diagnostic technologies that may be useful in point-of-care environments. Here we report the evaluation of 20 lateral flow immunoassays (LFAs) manufactured to detect antibodies specific to SARS-CoV-2 antigens in the blood of individuals exposed to the SARS-CoV-2 virus.
Readability and Invalids
In the table below we report, for each LFA, the sensitivity (% of COVID-exposed individuals for whom antibodies were successfully detected) and specificity (% of COVID-negative individuals for whom no antibodies were detected). We have reported the performance statistics such that discordant operator readings (i.e. two human operators disagree on the presence/absence of a band on the LFA) as a COVID-negative test result. This approach sacrifices some sensitivity for greater specificity; by reducing the number of false-positive readings tests are more likely to have better performance in the early stages of a disease outbreak where most individuals have not been exposed (see ‘Population-level Interpretation’ below).”
Indeterminate: The two operators did not agree, Invalid: The control band was absent, Positive: Two operators read a band, Negative: Two operators did not read a band.