4 research outputs found
Cross-validation of ELISA and a portable surface plasmon resonance instrument for IgG antibody serology with SARS-CoV-2 positive individuals.
We report on the development of surface plasmon resonance (SPR) sensors and matching ELISAs for the detection of nucleocapsid and spike antibodies specific to the novel coronavirus 2019 (SARS-CoV-2) in human serum, plasma and dried blood spots (DBS)
Assessment of the longitudinal humoral response in non-hospitalized SARS-CoV-2-positive individuals at decentralized sites: Outcomes and concordance
IntroductionEarly in the COVID-19 pandemic, reagent availability was not uniform, and infrastructure had to be urgently adapted to undertake COVID-19 surveillance.MethodsBefore the validation of centralized testing, two enzyme-linked immunosorbent assays (ELISA) were established independently at two decentralized sites using different reagents and instrumentation. We compared the results of these assays to assess the longitudinal humoral response of SARS-CoV-2-positive (i.e., PCR-confirmed), non-hospitalized individuals with mild to moderate symptoms, who had contracted SARSCoV-2 prior to the appearance of variants of concern in Québec, Canada.ResultsThe two assays exhibited a high degree of concordance to identify seropositive individuals, thus validating the robustness of the methods. The results also confirmed that serum immunoglobulins persist ≥ 6 months post-infection among non-hospitalized adults and that the antibodies elicited by infection cross-reacted with the antigens from P.1 (Gamma) and B.1.617.2 (Delta) variants of concern.DiscussionTogether, these results demonstrate that immune surveillance assays can be rapidly and reliably established when centralized testing is not available or not yet validated, allowing for robust immune surveillance
Cross-Validation of ELISA and a Portable Surface Plasmon Resonance Instrument for IgG Antibodies Serology with SARS-CoV-2 Positive Individuals
We
report on the development of surface plasmon resonance (SPR) sensors and
matching ELISAs for the detection of nucleocapsid and spike antibodies specific
against the novel coronavirus 2019 (SARS-CoV-2) in human serum, plasma and
dried blood spots (DBS). When exposed to SARS-CoV-2 or a vaccine against
SARS-CoV-2, the immune system responds by expressing antibodies at levels that
can be detected and monitored to identify the fraction of the population
potentially immunized against SARS-CoV-2 and support efforts to deploy a
vaccine strategically. A SPR sensor coated with a peptide monolayer and
functionalized with various sources of SARS-CoV-2 recombinant proteins expressed
in different cell lines detected human anti-SARS-CoV-2 IgG in the nanomolar
range. Nucleocapsid expressed in different cell lines did not significantly change
the sensitivity of the assays, whereas the use of a CHO cell line to express
spike ectodomain led to excellent performance. This bioassay was performed on a
portable SPR instrument capable of measuring 4 biological samples within 30
minutes of sample/sensor contact and the chip could be regenerated at least 9
times. Multi-site validation was then performed with in-house and commercial
ELISA, which revealed excellent cross-correlations with Pearson’s coefficients
exceeding 0.85 in all cases, for measurements in DBS and plasma. This strategy
paves the way to point-of-care and rapid testing for antibodies in the context
of viral infection and vaccine efficacy monitoring