In 45 vaccinated men over ~75 days, roughly 3/4ths saw a sperm increase or no change, and 1/4th (12 of them) saw a decrease.<p>This is 1% interesting but its very odd to test 45 men and not also test 45 random men in the same age bracket. What if the count difference is an approximation of seasonal differences between December and April? For example, there is a lot more opportunity physical activity for people generally in April, especially with lockdown easing. Is this just measuring <i>that?</i> In other words, is a 3/4th increase-or-no-change, 1/4th decrease the norm in the population over that time period regardless of vaccines? Does sperm count go up <i>more</i> for unvaccinated people during that period?!<p>It's possible that other studies could tell us this, but from the public study information and graph it seems surprisingly myopic.<p>FOR EXAMPLE (note this is sheep, I found the same for boars too, but if someone has a good human graph please post. Note the benefit of other mammals is that there is no selection bias in who shows up to get tested for such things.): <a href="https://www.researchgate.net/figure/Mean-monthly-sperm-concentration-x10-sperm-mL-recorded-in-Dorper-rams-using-the_fig1_272337914" rel="nofollow">https://www.researchgate.net/figure/Mean-monthly-sperm-conce...</a><p>Mean monthly sperm concentration in Dec and Jan: about 2600. In April, about 3400. That's a huge jump. What if that explains the entirety of these results? What if these vaccinated people have a lower than average variation! (And again, what if lockdown lifestyle changed things big time, and vaccinated people are doing more physical activity, etc etc.)
I'm a software developer. It has been years since I did anything even remotely scientific.<p>I do not like conspiracy theories. I do not adhere to any that I'm aware of.<p>Yet after reading the abstract, I'm left despairing. Just between the sample size and the glaring discrepancies in the sampling methodology before and after - so massive that they had to be mentioned in the abstract, and I'm left wondering who this is supposed to convince.<p>Sometimes conspiracy theory fighters are their own worst enemies.
Take with a grain of salt:<p>> The limitations of the study include the small number of men enrolled; limited generalizability beyond young, healthy men; short follow-up; and lack of a control group. In addition, while semen analysis is the foundation of male fertility evaluation, it is an imperfect predictor of fertility potential. Despite this, the study’s time frame encompasses the full life cycle of sperm.
Table of results (45 men):<p><pre><code> Before After
Semen Volume (ml) 2.2 2.7
Concentration (m/ml) 26 30
Motility (%) 58 65
TMSC (m) 36 44
</code></pre>
In the 2010 WHO data (<a href="https://www.who.int/reproductivehealth/topics/infertility/cooper_et_al_hru.pdf" rel="nofollow">https://www.who.int/reproductivehealth/topics/infertility/co...</a>)<p><pre><code> Percentile ml
2.5 1.2
5 1.5
10 2
25 2.7
50 3.7
75 4.8
90 6
95 6.8
97.5 7.6
</code></pre>
So these men had really low semen volume to start with.<p>The one thing I would note is that semen volume varies <i>a lot</i> over time. And so 45 men, taking two samples is really not a lot of data. My own data (samples 48 hours apart over a one month period) has median of 5.17 with IQR 4.91-5.84.
Results:<p>> After the second vaccine dose, the median sperm concentration significantly increased to 30 million/mL (IQR, 21.5-40.5; P = .02) and the median TMSC to 44 million (IQR, 27.5-98; P = .001). Semen volume and sperm motility also significantly increased (Table).<p>> Eight of the 45 men were oligospermic before the vaccine (median concentration, 8.5 million/mL [IQR, 5.1-12]). Of these 8, 7 men had increased sperm concentration to normozoospermic range at follow-up (median concentration, 22 million/mL [IQR, 17-25.5]), and 1 man remained oligospermic. No man became azoospermic after the vaccine.