You asked, we answered: Can mRNA vaccines cause infertility?

Women receiving vaccine


I have read that the vaccine causes infertility. That would be devastating. I guess it interferes with the formation of the placenta.

Answer from infectious diseases expert David Brett-Major, MD, MPH

The COVID-19 mRNA vaccines now have been in tens of thousands of people and infertility has not been a problem for men or women. 

Twenty-three women became pregnant after participating in Pfizer's mRNA vaccine clinical trial. Pfizer reported one poor pregnancy outcome in someone in the control/placebo group – meaning they had not received the vaccine.

There is a rumor that antibodies against the spike protein will also target a protein in the placenta of pregnant mothers, syncytin-1. There is no data suggesting that these antibodies will affect syncytin-1, as they are different proteins.

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