COVID Vax ‘Temporarily Impairs Semen Concentration’: Peer-Reviewed Medical Journal

The vaccine “is a reasonable cause for transient semen concentration and TMC decline,” according to the study.

  • An Israeli study published by the peer-reviewed medical journal Andrology titled “Covid-19 vaccination BNT162b2 temporarily impairs semen concentration and total motile count among semen donors” addressed concerns that Pfizer-BioNTech’s COVID-19 vaccine causes detrimental impact on male fertility.
  • The authors analyzed 37 semen donors from three sperm banks that provided 220 samples.
  • The study concluded that the COVID shots triggered an immune response that caused semen concentration to “temporarily” decline: “Systemic immune response after BNT162b2 vaccine is a reasonable cause for transient semen concentration and TMC decline,” the paper reads.
  • Even though the study showed vaccines cause “selective temporary deterioration of sperm concentration 3 months after vaccination resulting with impaired TMC,” the authors insist their work “should support vaccinations programs” instead of discouraging patients from receiving the jab.
  • However, the authors also emphasized how new studies “concentrating on different vaccines and populations (ex. subfertile patients) are urgently required.”

“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,” the study’s “Results” section reads. “Similarly, analysis of first semen sample only and samples’ mean per donor resulted in concentration and TMC reductions on T2 compared to T0 – median decline of 12 million/ml and 31 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. T3 evaluation demonstrated overall recovery. Semen volume and sperm motility were not impaired.”


  • The Andrology study was published in the U.S. National Institutes of Health’s (NIH) National Library of Medicine (NLM).
  • Andrology is the study of the male reproductive system and other male gender-related health issues, according to the journal’s description webpage. “Andrology deals with basic and clinical aspects of the male reproductive system (gonads, endocrine and accessory organs) in all species, including the diagnosis and treatment of medical problems associated with sexual development, infertility, sexual dysfunction, sex hormone action and other urological problems,” the description goes on to say. “In medicine, Andrology as a specialty is a recent development, as it had previously been considered a subspecialty of urology or endocrinology.”