Detection of recombinant Spike protein in the blood of individuals vaccinated against SARS‐CoV‐2: Possible molecular mechanisms

Abstract

PurposeThe SARS‐CoV‐2 pandemic prompted the development and use of next‐generation vaccines. Among these, mRNA‐based vaccines consist of injectable solutions of mRNA encoding for a recombinant Spike, which is distinguishable from the wild‐type protein due to specific amino acid variations introduced to maintain the protein in a prefused state. This work presents a proteomic approach to reveal the presence of recombinant Spike protein in vaccinated subjects regardless of antibody titer.Experimental designMass spectrometry examination of biological samples was used to detect the presence of specific fragments of recombinant Spike protein in subjects who received mRNA‐based vaccines.ResultsThe specific PP‐Spike fragment was found in 50% of the biological samples analyzed, and its presence was independent of the SARS‐CoV‐2 IgG antibody titer. The minimum and maximum time at which PP‐Spike was detected after vaccination was 69 and 187 days, respectively.Conclusions and clinical relevanceThe presented method allows to evaluate the half‐life of the Spike protein molecule “PP” and to consider the risks or benefits in continuing to administer additional booster doses of the SARS‐CoV‐2 mRNA vaccine. This approach is of valuable support to complement antibody level monitoring and represents the first proteomic detection of recombinant Spike in vaccinated subjects.

Back to the Basics of SARS-CoV-2 Biochemistry: Microvascular Occlusive Glycan Bindings Govern Its Morbidities and Inform Therapeutic Responses

“…Blood levels of SP, as with almost all drugs and other bioactive agents, are commonly misdetermined using plasma, an invalid detection method for RBC-binding molecules, which can have whole-blood-to-plasma ratios as high as 30 to one. Indeed, SP levels in the blood, which persist to detectable levels months after mRNA COVID-19 vaccination [ 72 ], have only been accurately determined using whole blood (see Section 8 ). A second oversight was the assumption that SARS-CoV-2 SP is harmless because it cannot replicate, yet it binds strongly to RBCs and endothelial cells, induces RBC aggregation in vitro [ 39 ] and causes damaging related effects in vivo [ 63 , 64 ].…”

“…The risk period for the occurrence of possible microvascular complications post-COVID-19 vaccination has not been established, but mass spectrometry analysis of whole blood detected SP in 50% of mRNA-vaccinated subjects up to six months after vaccination [ 72 ]. Another study found that of 16 COVID-19 mRNA-vaccinated patients hospitalized afterward for myocarditis, all had significant levels of SARS-CoV-2 SP in the blood, while 45 asymptomatic, vaccinated subjects had no detectable SP [ 73 ].…”

“…Blood concentrations of SARS-CoV-2 SP are reported in almost every case using plasma or serum, but this glycoprotein binds strongly to RBCs [ 1 ], e.g., with SP traces being found on 41% of RBCs from hospitalized COVID-19 patients in one study [ 40 ]. Although methodological differences preclude exact comparisons, one mass spectroscopic examination of whole blood found SP in 50% of blood samples from subjects up to six months after mRNA COVID-19 vaccination [ 72 ]. Other studies that used plasma or serum, however, found much lower SP levels [ 73 , 129 , 130 ], e.g., no detectable SP in any subject 10 days post-vaccination [ 130 ].…”

A new absolute quantitative method for peptide and metabolite detection

“…PROSAD technology 15 was been employed to calibrate the standard mixture. N‐acetylcysteine and LDPPEAEVQIDR peptide 16 were prepared at a concentration of 1 μg/ml, and progressive volumes of 1, 2, 5, and 10 μl were analyzed. The quantitation of mixture containing the two analytes was obtained by both the standard calibration curve based on peak area and also based on peak resolution.…”

SARS-CoV-2 Spike amyloid fibrils specifically and selectively accelerates amyloid fibril formation of human prion protein and the amyloid β peptide

“…Amyloid derived from SARS-CoV-2 spike protein has the potential to hamper fibrinolysis of seeded fibrin and hence might be one explanation for microclot formation in severe and long COVID-19 (20). Data from Brogna and colleagues demonstrate that Spike protein produced in the host as response to mRNA vaccine, as deduced by specific amino acid substitutions, persists in blood samples from 50% of vaccinated individuals for between 67 and 187 days after mRNA vaccination (23). Such prolonged Spike protein exposure has previously been hypothesized to stem from residual virus reservoirs, but evidently this can occur also as consequence of mRNA vaccination.…”