While the COVID-19 vaccine and male fertility have made headlines lately, there is no evidence as of now that the vaccine has any negative effect on male fertility. However, there is evidence indicating that contracting COVID-19 could make an impact.

So, where did the worry regarding the vaccine's potential impact on male fertility come from? Well, as the Henry Ford Health System in Detroit explained, it actually originated with concerns about women's fertility from Wolfgang Wodarg, an epidemiologist in Germany who, along with a former Pfizer employee, wrote a letter expressing his fears to the European Medicines Agency.

Both the Pfizer and Moderna vaccines use genetically engineered messenger RNA (mRNA). When the vaccine was in the infancy of its development, Wodarg theorized that because the spike protein the mRNA vaccines code for has a slight resemblance to the spike