Claim: The Covid-19 spike protein which the Pfizer vaccine causes an immune response against also trains the body to attack syncytin-1, a protein in the placenta, which could lead to infertility in women.
Fact-check: No evidence Pfizer Covid-19 vaccine affects women's fertility - Full Fact
Verdict: this claim has no basis. the spike protein on the covid-19 virus and a protein that makes up the placenta have only a small amount in common, almost certainly not enough for the immune system to attack the placenta.
Organisation: Full Fact
Author: Grace Rahman
Date published: 2020-12-08T00:00:00