EFFECT OF COVID-19 mRNA VACCINES ON SPERM QUALITY

ABSTRACT

OBJECTIVE: Fertility related safety data was neither reported in the clinical trials nor evaluated in animal models prior to emergency use authorization (EUA) for two novel mRNA vaccines, BNT162b2 and mRNA-127.1,2 Despite excellent safety profiles for both vaccines, 44% of Americans are hesitant in receiving the vaccine. Although the specific reasons for COVID-19 vaccine hesitancy are unknown, concerns over fertility has previously decreased other vaccine uptake. As COVID-19 vaccination in the United States opens to children and adolescents, evaluating any potential impact of the vaccine on male reproduction is imperative for public reassurance. We hypothesized that since both vaccines only contain mRNA encoding the SARS-CoV-2 spike protein without biologic ability to replicate live virus, the vaccines would not decrease semen parameters. MATERIALS AND METHODS: We conducted a single-center prospective cohort study after IRB approval from the University of Miami (#20201451). Healthy men aged 18-50 scheduled for mRNA COVID-19 vaccination in Miami, Florida were recruited.Participants provided a semen sample after 2-7 days of abstinence, prior to receiving the first dose of either vaccine and about 72 days after the second dose. Specimens were self-collected into a wide-mouth sterile container and semen analysis (SA) performed by HCLD trained andrology clinicians examined semen volume, concentration, motility, and total motile sperm count (TMSC). RESULTS: 45 men provided a semen sample. Neither median sperm concentration nor total motile sperm count (TMSC) declined post vaccination (Figure 1). There was no clinically significant change in TMSC. Only 12 (26.6%) men had a marginal decrease in TMSC. In fact, the remaining 33 (73.3%) men demonstrated normal sperm parameters. Importantly, 8 (17%) men with oligospermia prior to vaccination did not experience a decrease in spermatogenesis. Only one subject had an abnormal TMSC (TMSC ≤ 9) after vaccination. CONCLUSIONS: After receiving the two doses of the vaccines, we did not observe a clinically significant sperm parameter decline within the cohort, suggesting the vaccines do not negatively impact male fertility potential. IMPACT STATEMENT This is the first male fertility evaluation of the COVID-19 mRNA vaccines, in which we found that the vaccines do not negatively impact semen parameters. (Table Presented).