How did COVID-19 vaccination affect sperm characteristics?

In a recent study published in Asian Journal of Andrologyresearchers evaluated the impact of coronavirus disease 2019 (COVID-19) vaccination on sperm characteristics.

Background

Regarding the impact of COVID-19 on male fertility, one of the non-respiratory symptoms is that decreased spermatogenesis may reflect the course of infection. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with decreased sperm quality, but its reproductive toxicity has not been evaluated in the clinical setting. Previous studies have linked sperm quality and fertility to population mortality and health. Therefore, vaccination can significantly affect sperm parameters.

About research

In this study, researchers examined differences in sperm parameters before and after administration of various SARS-CoV-2 vaccines.

We integrated Embase and PubMed databases with search phrases (vaccination, COVID-19, sperm parameters) to discover candidate studies. According to the Principle of Population, Intervention, Comparison and Outcome (PICOS), the team selected papers that met the criteria for inclusion in the meta-analysis. quality; (2) I (intervention): SARS-CoV-2 vaccination was the only intervention; (3) C (comparative): comparisons made between vaccinated and unvaccinated populations and the included participants themselves. (4) O (outcome): results such as semen volume, sperm concentration, and associated assessments such as total motility of sperm. The effects of the messenger ribonucleic acid (mRNA) COVID-19 vaccine on semen volume, sperm concentration, total sperm count, and total sperm motility were evaluated before and after COVID-19 vaccination.

result

Seven studies screened in the database were assessed for quality and included in the quantitative analysis. Comparison of semen variables before and after COVID-19 vaccination included 6 studies with 920 patients for sperm concentration and semen volume, 6 studies with 1674 patients evaluating total sperm motility, 1110 Data from two studies involving patients were required. Two studies involving 332 patients for total sperm count, and morphological evaluation. The team noted significant variability in global sperm motility before and after COVID-19 vaccination, but significant heterogeneity was also noted. A funnel plot showed that this comparison was free of appreciable publication bias.

There was no change in the amount before and after vaccination against COVID-19. Furthermore, no discernible heterogeneity was found. No substantial publication bias was found in this comparison. Given that fluids greatly affect sperm count, this overall result is credible. Therefore, this feature may primarily represent the effect of vaccination on fluid-secreting glands. There was no evidence of heterogeneity among the primary outcomes of the included studies. Overall, there was no change in sperm concentration before and after COVID-19 vaccination.

The team did not observe a significant decrease in total sperm count after COVID-19 vaccination. Three studies examined a comparison of sperm morphology, with one study reporting abnormal proportions and two studies reporting normal proportions. Barring considerable heterogeneity, there were no discernible morphological changes after immunization.

Overall, the study results indicated that the most recent evidence reported that administration of inactivation or mRNA COVID-19 vaccine did not adversely affect sperm parameters. The researchers believed that additional prospective structured studies were urgently needed to confirm this conclusion.