Sperm counts before and after the COVID-19 vaccine.


More good news about the safety of the COVID-19 vaccines and male fertility: a study published in JAMA documented semen analysis parameters before and after the COVID-19 vaccine. I referred to it in a previous post when the study was still ongoing.


The findings were enlightening:


Men ages 18-50, provided sperm samples before vaccination, then about 70 days after the second dose. Of the 45 volunteers who bravely ejaculated twice in the name of science, 21 received the Pfizer vaccine and 24 received Moderna. 


After the second vaccine dose, the median sperm concentration, total motile count, semen volume, and sperm motility all significantly increased. Furthermore, of 8 men who had low sperm counts in their first sample, 7 had concentrations improved to the normal range after the vaccinations.


Does that mean the COVID-19 vaccines improve sperm counts? Probably not, and the authors were smart to point that out. To be transparent, the data documented that were some men in the study whose concentrations did decrease somewhat. The authors state that “the magnitude of change is within normal individual variation and may be influenced by regression to the mean.”   


The moderation in their conclusion is admirable. If there was any other intervention  (think vitamins, supplements, etc) that led to a statistical improvement in sperm counts, we would be quick to declaring a miracle cure. Certainly, if the opposite were true and the numbers went in the wrong direction, critics would be quick to vilify the vaccine.


At the very least, this study confidently reassures us that the vaccine did not harm the sperm counts. Let the data speak for itself.




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