1Department of Biomolecular Sciences,
University of Urbino Carlo Bo, Urbino; 2National
Institute for Nuclear Physics (INFN)-Gran Sasso National Laboratory
(LNGS), Assergi, L’Aquila, Italy.
Corresponding author: Loris Zamai, Department of Biomolecular
Sciences, via Ca’ le Suore 2, University of Urbino Carlo Bo, 61029
Urbino, Italy.
e-mail:loris.zamai@uniurb.it
Data sharing is not applicable to this article because no new data were
created or analysed in this study
Key words: Vaccine; immunity; viral vectors; SARS-CoV-2 variants;
zinc-metalloproteases; chelating agents.