Severe acute respiratory syndrome corona virus (SARS-CoV)-2 obtained from patients infected despite being fully vaccinated with either BNT162b2 (Pfizer/BioNTech), mRNA-1273 (Moderna), or JNJ-78436735 (Janssen) showed increased mutations rates in the N-terminal domain (NTD) and receptor-binding domain (RBD) of the spike glycoprotein when compared with virus from unvaccinated controls (1). These changes are associated with immune evasion and diagnostic failures, prominent characteristics of variants of concern (2). Variants of concern (VOC) appeared to be overrepresented in numerous breakthrough infections of fully vaccinated people in the United States and (1, 3-6), and Israel (7). These findings confirm concerns about the relation of SARS-CoV-2 variants with vaccine breakthrough, and urged us to attempt clarifying the likely link between vaccination with the currently used vaccines and VOC emergence.