Effects of inactivated SARS‐CoV‐2 vaccination on male fertility: A retrospective cohort study

Abstract

Numerous studies have revealed severe damage to male fertility from severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection, raising concerns about the potential adverse impact on reproductive function of the coronavirus disease 2019 (COVID‐19) vaccine developed based on the virus. Interestingly, there are several researchers who have studied the impact of the COVID‐19 mRNA vaccine since then but have come up with conflicting results. As a near‐ideal candidate for mass immunization programs, inactivated SARS‐CoV‐2 vaccine has been widely used in many countries, particularly in less wealthy nations. However, little is known about its effect on male fertility. Here, we conducted a retrospective cohort study at a single large center for reproductive medicine in China between December 2021 and August 2022. Five hundred and nineteen fertile men with no history of laboratory‐confirmed COVID‐19 were included and categorized into four groups based on their vaccination status: unvaccinated group (n = 168), one‐dose vaccinated group (n = 8), fully vaccinated group (n = 183), and booster group (n = 160). All of them underwent a semen analysis and most had serum sex hormone levels tested. There were no significant differences in all semen parameters and sex hormone levels between the unvaccinated group and either vaccinated group. To account for possible vaccination‐to‐test interval‐specific changes, sub‐analyses were performed for two interval groups: ≤90 and >90 days. As expected, most of the semen parameters and sex hormone levels remained unchanged between the control and vaccinated groups. However, participants in vaccinated group (≤90 days) have decreased total sperm motility and increased follicle‐stimulating hormone level compared with the ones in unvaccinated group. Moreover, some trends similar to those found during COVID‐19 infection and recovery were observed in our study. Fortunately, all values are within the normal range. In addition, vaccinated participants reported few adverse reactions. No special medical intervention was required, and no serious adverse reactions happened. Our study suggests that inactivated SARS‐CoV‐2 vaccination does not impair male fertility, possibly due to the low frequency of adverse effects. This information reassures young male population who got this vaccine worldwide, and helps guide future vaccination efforts.

Comprehensive evaluation of inactivated SARS-CoV-2 vaccination on sperm parameters and sex hormones

“…observed that there were no significant differences in semen parameters (volume, sperm concentration, progressive motility and total progressive motile count) before and after receiving first or second dose of the vaccine ( 14 ). Our previous study also showed similar results ( 15 ). However, these studies focused on evaluating the effect of each individual dose vaccination, while the influence of combined doses of vaccines on human fertility has not been assessed in detail.…”

“…Although some studies have found a temporary decrease in sperm concentration and total sperm motility after 1 + 2 doses of mRNA vaccination compared to unvaccinated men, whether this conclusion applies to inactivated vaccines remains to be verified ( 16 , 17 ). Moreover, most of the participants included in previous studies on inactivated vaccines underwent semen analysis only once, making it difficult to use a pre and post control group design to eliminate confounding factors and selection bias ( 15 , 18 , 19 ). Therefore, we performed this study to comprehensively investigate the effect of inactivated COVID-19 vaccination on male fertility, hoping to provide more valuable information for future public health efforts.…”

Effects of COVID-19 vaccination on human fertility: a post-pandemic literature review

“…Like Gat et al.’s report on mRNA vaccine, Dong et al. also found a deterioration in semen parameters in the short term, the population within 90 days of vaccination displayed decreased total sperm motility compared to that in the unvaccinated population [ 24 ]. We speculate that the fever after vaccination may be the reason for the parameter deterioration, since researches had proved that fever can temporarily impair sperm count and quality [ 72 ].…”

“…Relatively little research on inactivated COVID-19 vaccine is available, mainly reported by scholars in China, who have the most applications for inactivated COVID-19 vaccine. Two retrospective studies included an unvaccinated population in the control group, and the results showed that the population vaccinated with inactivated COVID-19 vaccine had comparable semen parameters and pregnancy rates [ 24 , 86 ]. Like Gat et al.’s report on mRNA vaccine, Dong et al.…”

SARS-CoV-2 Vaccines-Related Endocrine Disorders: An Updated Narrative Review

“…Six other retrospective studies examined various vaccine types (mRNA, inactivated, and viral vector vaccines) on sperm quality characteristics. Three studies investigated healthy men [163][164][165] and three individuals undergoing fertility treatments [166][167][168]. Overall, sperm characteristics were not influenced after vaccination, excluding a temporary decrease in concentration and motility in one study and decreased total sperm motility with increased FSH levels compared with the men in the unvaccinated group in another study; both studies focused on healthy donors [166,168].…”