anti-syncytin-1 antibodies

The preprint of a new study titled “Addressing anti-syncytin antibody levels, and fertility and breastfeeding concerns, following BNT162B2 COVID-19 mRNA vaccination” became available online on May 25 2021. The authors “investigated post-vaccination mRNA persistence and anti-syncytin-1 antibodies in plasma and breast milk in female at-risk front-line workers and vaccine recipients.” The bias of the authors is