ERVW-1 and COVID-19: However, in the case of COVID-19 mRNA vaccines, there were concerns disseminated on social media platforms claiming higher risk of miscarriage due to the formation of antibodies that could cross the placenta and bind to the spike protein called syncytin-1, a critical protein in the formation of the syncytiotrophoblast layer of the human placenta and embryogenesis (Blake Evans et al., 2021).