Vaccination with either mRNA or Vector-Based COVID-19 Vaccine has no Detectable Effect on Sperm Parameters

Background: With the introduction of COVID-19 vaccines in 2021, concerns arose regarding their impact on male fertility. Therefore, this study investigated the effect of mRNA- and vector-based COVID-19 vaccination on male fertility by analyzing sperm parameters in subjects with unrestricted and restricted fertility. Methods: In this prospective self before-after control study at a single University-based Infertility Center in Duesseldorf, Germany, a total of 25 male subjects were recruited, who were scheduled to receive their first vaccination against COVID-19 between January and August 2021. Semen samples were obtained before and after the first COVID-19 vaccination to perform an analysis of semen quality according to the 2010 World Health Organization guideline. Main outcome measures were ejaculate volume, sperm concentration, total sperm number, percentage of sperm motility and sperm morphology. Results: There were no significant changes in sperm parameters before and after the vaccination. Conclusion: Both, mRNA and vector-based COVID-19 vaccination had no short-term effect on sperm parameters. Therefore, an influence of COVID-19 vaccination on male fertility appears to be very unlikely.