Monitoring Serum Spike Protein with Disposable Photonic Biosensors Following SARS-CoV-2 Vaccination

Abstract

While mRNA vaccines have been well-studied in vitro and in animals prior to their use in the human population during the Covid-19 pandemic, their exact mechanisms of inducing immunity are still being elucidated. The large-scale collection of data necessary to fully understand these mechanisms, and their variability across heterogeneous populations, requires rapid diagnostic tests that accurately measure the various biomarkers involved in the immune response following vaccination. Recently, our lab developed a novel “Disposable Photonics” platform for rapid, label-free, scalable diagnostics that utilizes photonic ring resonator sensor chips combined with plastic micropillar cards able to provide passive microfluidic flow. Here, we demonstrate the utility of this system in confirming the presence of SARS-CoV-2 spike protein in the serum of recently vaccinated subjects, as well as tracking a post-vaccination rise in anti-SARS-CoV-2 antibodies. A maximum concentration in SARS-CoV-2 spike protein was detected one day after vaccination and was reduced below detectable levels within 10 days. This highlights the applicability of our rapid photonic sensor platform for acquiring the data necessary to understand vaccine mechanisms on a large scale, as well as individual patient responses to SARS-CoV-2 mRNA vaccines.

The effect of an mRNA vaccine against COVID-19 on endothelial function and arterial stiffness

“…Furthermore, experimental data show the entrance of the spike protein in cardiac pericytes and pulmonary vascular cells, which promotes cell signaling leading to vascular cell dysfunction and cell growth/hypertrophy [ 28 , 29 ]. It seems extremely interesting to be able to detect spike protein levels in plasma [ 30 , 31 ], but to the best of our knowledge, no practical, clinical use has been implemented thus far while these techniques are not widely available for use to investigate whether there is an association between the observed changes in endothelial function and the spike levels in plasma [ 32 ].…”

Understanding viruses and viral infections by biophotonic methods

“…With their platform, the authors investigated serum samples of recently vaccinated test subjects over a time course of 70 days (Figure 19B) [221]. Despite the reported LOD of just 4.2 μg/mL for the spike protein, the observed concentration patterns were in good agreement with data from clinical trials [221]. To conclude this section, two recent reports on fully integrated diagnostic devices are especially recommended to the reader.…”

“…Reprinted (adapted) from Ref. [221] with permission of MDPI. A low-cost and portable LIT device for quantitative read-out of Au particles in commercial LFAs (C, left panel) together with bright-field and thermo-photonic amplitude images of test cassettes developed at various IgG concentrations (C, right panel).…”

“…[222] with permissions of American Chemical Society magnitude of shifting is directly proportional to the number of molecules bound to the resonator surface, allowing for direct quantification. Chips were tailored to either detect SARS-CoV 2 spike protein or human COVID-19 Ig's together with additional supplied bovine serum albumin serving as an internal reference for correct shift estimations [221]. With their platform, the authors investigated serum samples of recently vaccinated test subjects over a time course of 70 days (Figure 19B) [221].…”

Effects of spike protein and toxin-like peptides found in COVID-19 patients on human 3D neuronal/glial model undergoing differentiation: Possible implications for SARS-CoV-2 impact on brain development

“…Ogata et al, by using a Quanterix assay, found that spike protein levels in the blood of people vaccinated with mRNA-1273 was < 50 pg/mL after vaccination [129] , i.e., several orders of magnitude lower than the levels of spike tested in our study. On the other hand, Cognetti and Miller, by using a Disposable Photonics platform, found that 1-3 days after injection of mRNA vaccine BNT162b2, spike levels underwent an average shift of 15 pm, which corresponds to a maximum concentration of 14.6 μg/mL, returning to a baseline level in less than a month [130] . The discrepancy between the two studies is high and not yet validated.…”