Gat et al.: "Covid-19 vaccination BNT162b2 temporarily impairs semen concentration and total motile count among semen donors"; we are seeing impacts on menstrual cycle & in male testis

by Paul Alexander

This longitudinal study focused on SD demonstrates selective temporary sperm concentration and TMC deterioration 3 months after vaccination



‘Repetitive measurements revealed −15.4% sperm concentration decrease on T2 (CI −25.5%–3.9%, p = 0.01) leading to total motile count 22.1% reduction (CI −35% – −6.6%, p = 0.007) compared to T0. Similarly, analysis of first semen sample only and samples' mean per donor resulted in concentration and total motile count (TMC) reductions on T2 compared to T0 - median decline of 12 million/ml and 31.2 million motile spermatozoa, respectively (p = 0.02 and 0.002 respectively) on first sample evaluation and median decline of 9.5 × 106 and 27.3 million motile spermatozoa (p = 0.004 and 0.003, respectively) on samples' mean examination.’

‘Over the first pandemic months, there was insufficient data regarding the possible impact of Covid-19 on human reproduction. Yet, it was clear it employs the Angiotensin-Converting Enzyme 2 (ACE2) receptor for cellular entry.34 Various testicular cells including Leydig, Sertoli, spermatogonia and spermatozoa express ACE2 and related proteases resulting with viral fusion.56 Cytokine storm-induced dysfunction, autophagy regulation and damaged blood-testis barrier were also suggested as possible pathogenic mechanism for testicular damage.7 Clinical reports of orchitis, supported by histological findings, further emphasized testicular involvement.89 Therefore, detrimental impact on both spermatogenesis and testosterone production10 seem an obvious outcome. However, studies focused on Covid-19 detection on semen and testis resulted with conflicting results.7

Since the identification of the SARS-CoV-2 virus and its genome, an exceptional effort by the scientific community has led to the development of over 300 vaccine projects.11 The rapid and successful development of the BNT162b2 vaccine, providing 95% protection 7 days after second dose,12 is a notable scientific achievement. Israel was the first country to establish nationwide vaccination campaign. While initial candidates for vaccination were health care workers and citizens older than 65 years, gradual growing availability of the vaccinations enabled expansion of the campaign to all citizens older than 16 years.13 Unfortunately, vaccine hesitancy due to various reasons, including fears of “potential damage” to fertility is a major threat to vaccination programs' success.14 Consequently, scientific answers are required based on objective methodological standards. There have been few studies regarding the impact of COVID-19 vaccine of semen parameters, resulting with overall reassuring results, some even reported parameters improvements post-vaccination.15-17 However, careful examination raises two questions. First, is there a biological rationale for semen parameters improvement post-vaccination? Second, since semen analysis (SA) may vary significantly over time, what is the reliability of studies that include minimal samples per patient before and after vaccination?’