"Detection of recombinant spike protein in plasma from vaccinated against SARS-CoV-2 individuals".

The unfortunate advent of the SARS-CoV-2 pandemic has given a new push to the development and use of a next-generation of vaccines. Among them, mRNA-based vaccines consist of injectable solutions of mRNA encoding for a recombinant spike, which is distinguishable from the wild-type protein by the presence of specific amino acid variations introduced to maintain the protein in a prefusion state. Here, we present a proteomic approach to reveal the recombinant spike protein in vaccinated subjects to detect its presence independently of antibody titer. This approach is of valuable support to complement antibody level monitoring and represents the first proteomic detection of the recombinant spike in the vaccinated individual