Additionally, no evidence of anti-syncytin-1 antibody was found following COVID-19 mRNA vaccination [70], there is no evidence of cross-reactivity of anti-SARS-CoV-2 spike protein antibodies with syncytin-1 [68], and several studies confirmed no association between an increased rate of infertility in females or males and COVID-19 vaccination [71, 72]. This evidence concerns the gene ERVW-1 and Infertility.