Human semen quality as affected by SARS-CoV-2 infection: An up-to-date review

Association between inactivated COVID-19 vaccine and semen quality among males recovered from omicron infection: a retrospective cohort study

BACKGROUND

The protective effects of inactivated COVID-19 vaccines against SARS-CoV-2-associated semen impairment remain underexplored. We aimed to investigate the association between BBIBP-CorV vaccination and semen quality in males recovering from SARS-CoV-2 infection.

RESEARCH DESIGN AND METHODS

This single-center retrospective cohort study included males recovering from SARS-CoV-2 infection at a tertiary hospital in Urumqi, China (February-May 2023). Participants were categorized into long-term (> 90 days) and short-term (≤ 90 days) effects groups based on the interval between semen collection and their most recent SARS-CoV-2 infection. The study assessed the association between different doses of BBIBP-CorV vaccination and semen quality in both groups.

RESULTS

A total of 1496 participants were recruited for the short-term (n = 307) and long-term effect groups (n = 1189). Participants had a median age of 32 (IQR: 30, 35) years. Compared to unvaccinated controls, 2-dose and 3-dose recipients showed reduced risk of semen quality impairment in short-term, with adjusted relative risk (RR) of 0.945 (95% CI 0.918, 0.973) and 0.965 (95% CI 0.937, 0.993), respectively. No significant results were found for long-term effect groups.

CONCLUSION

Inactivated COVID-19 vaccination may protect against semen quality impairment in males recovering from SARS-CoV-2 Omicron infection within 90 days, particularly in semen volume and sperm progressive motility.

COVID-19 and Oncofertility: No SARS-CoV-2 in Semen but Inflammation Seems to Affect Sperm Parameters

The COVID-19 pandemic, driven by SARS-CoV-2, led authorities to recommend halting assisted reproductive technology programs, focusing instead on fertility preservation, for cancer patients. The presence of SARS-CoV-2 in semen remains controversial. This multicentric prospective cohort study, conducted across 12 university medical centers, aimed to determine if SARS-CoV-2 is present in spermatozoa/seminal plasma in cancer patients by RT-PCR and to assess its impact on standard semen parameters. The levels of cytokines and TNF-α were measured in seminal fluid by ELISA. We enrolled 129 men who underwent sperm cryopreservation between July 7, 2020, and June 30, 2021. The 63 were included and tested for COVID-19 in nasal swab samples by RT-PCR and/or by serology. All patients were asymptomatic on the day of semen collection: 50 were uninfected, 8 had a positive nasal swab (PCR+) and 5 were seropositive. SARS-CoV-2 RNA was not detected in the seminal fluid or spermatozoa. Ejaculate volume was significantly lower in the PCR+ group compared to the uninfected group (median [IQR]: 2.6 mL [1.6-3.4] vs. 4.6 mL [2.6-5.2] p < 0.05). Total and progressive motility were lower in the PCR+ group compared to the seropositive group (32.5% [25.0-45.0] vs. 50% [49.0-55.0] p < 0.05, and 22.5% [10.0; 32.5] vs. 44.5% [40-49] p < 0.05). Higher TNF-α level was observed in the PCR+ group (1.9 pg/mL [0-3.9]) compared to the uninfected group (0 pg/mL [0-0.4]) p < 0.05. Although SARS-CoV-2 was not detected in the sperm samples of cancer patients who were PCR+, the infection appears to impact sperm parameters, likely due to inflammation.

Effect of SARS-CoV-2 on semen parameters: A meta-analysis of 39 articles from 15 countries

Background

Declining birth rates during the pandemic have led to concerns about the potential impact of the of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on fertility among men. As previous studies have had inconsistent conclusions, we conducted a meta-analysis to evaluate the effects of SARS-CoV-2 on semen parameters.

Methods

We searched several databases for articles published between 1 January 2020 and 25 July 2023. We performed a robust screening process based on predetermined inclusion and exclusion criteria and, following quality assessment, extracted data from high-quality studies for the meta-analysis. We determined the P-values and 95% confidence intervals (CIs) for both continuous and dichotomous variables, which we described using mean differences (MDs) and odds ratios (ORs), respectively. Lastly, we used the leave-one-out approach for our sensitivity analysis, and Begg's and Egger's tests to determine publication bias.

Results

We included 39 articles with 1887 cases and 2097 controls. In patients infected with SARS-CoV-2, the sperm volume (MD = -0.29; 95% CI = -0.50, -0.07; P = 0.008) and concentration (MD = -8.71; 95% CI = -16.94, -0.48; P = 0.04) were decreased, which increased oligospermia risk (OR = 2.49; 95% CI = 1.04, 5.99; P = 0.04). Furthermore, we observed reduced sperm motility (MD = -8.18; 95% CI = -12.19, -4.17; P < 0.001) and increased immotility (MD = 4.06; 95% CI = 1.57, 6.54; P = 0.001) in infected patients, which increased asthenospermia risk (OR = 3.86; 95%CI = 1.83, 8.14; P = 0.0004). We also saw a decreased proportion of semen with normal sperm morphology (MD = -1.67; 95% CI = -2.68, -0.66; P = 0.001) and an increased proportion of semen with abnormal sperm morphology (MD = -1.31; 95% CI = -2.14, -0.49; P = 0.002,), along with increases in teratospermia (OR = 1.98; 95% CI = 1.00, 3.92; P = 0.05) in infected compared non-infected patients. Although we found consistency within most subgroups, we observed differences in severity, follow-up time, and country of origin. The results of the main meta-analysis results remained stable in the sensitivity analysis, while Begg's and Egger's tests showed no publication bias.

Conclusions

Based on sufficient evidence, we see that the effects of SARS-CoV-2 on semen parameters resulted in a decline in male fertility. The increased severity and shorter duration of the SARS-CoV-2 infection increased the likelihood of altering of semen parameters.

Registration

INPLASY: INPLASY202420083.

Effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus (COVID-19) vaccination on male fertility

Coronavirus disease 2019, which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains an ongoing global public health challenge. This disease causes damage not only to the respiratory system, affecting the normal physiological function of the lungs, but also to other vital organs, such as the heart and testicles. Existing studies have shown that co-expression of angiotensin-converting enzyme 2 and transmembrane serine protease 2 is the main mechanism by which SARS-CoV-2 invades host cells. Angiotensin-converting enzyme 2-expressing cells are widespread in the corpus cavernosum, reproductive tract and testis of men, which has raised concerns. Furthermore, abnormal sex hormone levels and decreased semen parameters were observed in coronavirus disease 2019 patients. This study comprehensively assessed the effects of SARS-CoV-2 infection on the testis, semen parameters, sex hormone levels and erectile function, and discussed possible transmission routes during sexual intercourse and the effect of vaccination on male fertility.

Effect of COVID-19 on sperm parameters: pathologic alterations and underlying mechanisms

The rapid outbreak of the coronavirus disease 2019 (COVID-19) pandemic has brought challenges to different medical fields, especially reproductive health. To date, most studies on the effects of COVID-19 on male reproduction have some limitations. In addition, there is little research on the mechanisms underlying by which severe acute respiratory syndrome coronavirus 2 infection affects semen quality. Here, we revealed the possible impact of COVID-19 on sperm parameters and the potential mechanisms. At present, it is still controversial whether COVID-19-induced fever adversely affects sperm parameters. Severe acute respiratory syndrome coronavirus 2 can induce up-regulation of pro-inflammatory cytokine, which leads to the destruction of blood-testis barrier and impairment of spermatogenesis. Moreover, severe viral infection of the respiratory system could induce systemic oxidative stress. Sperm are highly vulnerable to it due to their limited levels of antioxidant defense, unsophisticated DNA damage detection and repair mechanisms. Our review prompt medical staff and patients to consciously check the reproductive function of COVID-19 male patients. Moreover, opening our prospective beyond the direct infection could be the key to better understand the COVID-19 short and long-term effects and provide a new idea for future treatment of patients with reproductive function injury.

A systematic review of the effect of COVID-19 on semen parameters

Background and objectives

Since the outbreak of COVID-19, more and more studies have proved that it has an impact on the male reproductive system. The purpose of this article is to investigate the effects of COVID-19 on male semen parameters, further analyze the incidence and risk factors of diseases related to semen parameters, and put forward to corresponding preventive measures.

Methods

Retrieved from PubMed, Embase, The Cochrane Library, Web of Science, Clinicaltrails, CNKI, CBM, Wanfang Database and VIP to collect research on the effects of COVID-19 on the male reproductive system. The literature search was conducted until January 2022. In strict accordance with the inclusion and exclusion criteria, two researchers independently screened the literature and comprehensively analyzed five cohort studies on the impact of COVID-19 on male reproductive system. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the included cohort studies, and Revman 5.4.1 was applied for statistical analysis.

Results

Semen volume (RR = −0.10; 95% CI: 0.45, 0.26; P = 0.60), there was no significant difference between the test group and the control group; Sperm count (RR = −45.28; 95% CI: 66.38, 24.19; P = 0.0001), the sperm count of the COVID-19 test group was lower than that of the control group, and the difference was statistically significant; Sperm concentration (RR = −15.65 × 106; 95%CI: 31.52 × 106, 0.21 × 106; P = 0.05), there was no significant difference between the test group and the control group; progressive sperm motility (RR = 4.31; 95% CI: 4.62, 13.24; P = 0.34), there was no effect on progressive sperm motility in the COVID-19 test group compared with the control group.

Conclusions

COVID-19 can reduce semen quality and affect male fertility. However, due to the limitations of this study, this conclusion needs to be further verified by large-sample, high-quality prospective cohort studies on the long-term effects of COVID-19 on male reproductive function.

Cryopreservation of Human Spermatozoa: Functional, Molecular and Clinical Aspects

Cryopreservation is an expanding strategy to allow not only fertility preservation for individuals who need such procedures because of gonadotoxic treatments, active duty in dangerous occupations or social reasons and gamete donation for couples where conception is denied, but also for animal breeding and preservation of endangered animal species. Despite the improvement in semen cryopreservation techniques and the worldwide expansion of semen banks, damage to spermatozoa and the consequent impairment of its functions still remain unsolved problems, conditioning the choice of the technique in assisted reproduction procedures. Although many studies have attempted to find solutions to limit sperm damage following cryopreservation and identify possible markers of damage susceptibility, active research in this field is still required in order to optimize the process. Here, we review the available evidence regarding structural, molecular and functional damage occurring in cryopreserved human spermatozoa and the possible strategies to prevent it and optimize the procedures. Finally, we review the results on assisted reproduction technique (ARTs) outcomes following the use of cryopreserved spermatozoa.

The Impact of COVID-19 Vaccines on Male Semen Parameters: A Retrospective Cohort Study

The emergence of SARS-CoV-2 and the subsequent COVID-19 pandemic necessitated the development of adequate vaccines. Despite vaccines being demonstrated to be safe and effective for preventing severe disease and death, vaccine hesitancy remains. Reasons include concerns over adverse effects on male fertility, which have not been widely investigated. Therefore, this study is aimed at determining the impact of COVID-19 vaccination on semen parameters in a retrospective cohort study of South African males undergoing fertility assessment. The patients for this study were adult men who have previously undergone routine semen analysis for fertility assessment at Androcryos Andrology Laboratory (Johannesburg, South Africa) between March 2021 and March 2022. They also received vaccination within 3 months following a semen analysis and underwent a second semen analysis any time post-COVID-19 vaccination. From 277 records analysed, 46 patients met the inclusion criteria, receiving the Pfizer-BioNTech (BNT162b1) (63%), Johnson and Johnson (JNJ-78436735/Ad26.COV2S) (34.8%), and the AstraZeneca (AZD1222) (2.2%) vaccines. Sperm concentration significantly increased postvaccination ( $P=0.0001$ ), with no significant changes in semen pH, volume, total sperm count, progressive motility, normal sperm morphology, or chromatin condensation. Results were not influenced by age, type of vaccine received, and the number of days following vaccination, as depicted by multiple regression analysis. In conclusion, there is no evidence of a negative impact of COVID-19 vaccination on male semen parameters, which is consistent with the emerging literature on COVID-19 vaccination and male fertility. COVID-19 vaccinations should not be dismissed based on fear of adverse effects on male fertility parameters.

COVID-19 and its treatments: lights and shadows on testicular function

PURPOSE

The SARS-CoV-2 pandemic has rapidly spread worldwide and, among the others, the male gender was quickly recognized as an independent risk factor for both the disease and its consequences. Since the possibility of long-term hormonal axis changes and male gamete impairment have been hypothesized but a relatively low levels of evidence has been reached, we focused this narrative mini-review on summarizing key state-of-the-art knowledge on male reproductive effects of COVID-19 as a quick reference for reproductive health specialists.

METHODS

A comprehensive Medline/PubMed and Embase search was performed selecting all relevant, peer-reviewed papers in English published from 2020. Other relevant papers were selected from the reference lists.

RESULTS

Available evidence indicates that the likelihood of direct testicular damage from SARS-CoV-2 is somewhat low, but there are many indirect ways (fever, cytokine imbalance, and drugs) through which the pituitary-gonadal axis and spermatogenesis may be disrupted. These alterations are probably transient, but as available evidence is low quality, it cannot be excluded that previous pathologies or comorbidities might modulate the risk of their persistence. On the other hand, available evidence shows high safety regarding andrological health for available vaccines, although studies are mainly focused on mRNA vaccines.

CONCLUSION

A careful andrological evaluation of men recovering from COVID-19 is highly recommended. Since available evidence is relatively scarce, a careful andrological follow-up and counseling of these patients are mandatory.

Semen quality changes during infection and recovery phases of mild-to-moderate COVID-19 in reproductive-aged patients: a prospective case series

BACKGROUND

Despite the documented effects of the coronavirus disease 2019 (COVID-19) on spermatogenesis, the reversibility of these effects is uncertain. We aimed to assess the changes of sperm quality between the infection and recovery phases of COVID-19 in reproductive-aged men. The semen quality of men with mild-to-moderated COVID-19 (defined by the degrees of symptoms and chest involvement on computed tomography) was studied during October, 2020-May, 2021 at our hospital. Two semen samples were analyzed at timings estimated to represent spermatogenic cycles during the infection and recovery phases of COVID-19.

RESULTS

A total of 100 patients were included with mean ± SD (range) age of 24.6 ± 3.3 (21-35) years. During infection, 33% of patients had abnormal semen quality. However, a significant reduction was found in this abnormality from 33 to 11% (P < 0.001) after recovery from infection. In a comparison of the two semen analyses, there were significant improvements in the mean values of sperm progressive motility (P =0.043) and normal morphology (P < 0.001). However, the mean sperm concentration showed a statistically insignificant increase (P = 0.844).

CONCLUSIONS

In reproductive-aged patients with mild-to-moderate COVID-19, the effects on seminal quality were recoverable, represented by significant improvements in the means of progressive sperm motility and normal morphology between the infection and recovery phases of COVID-19.

TRIAL REGISTRATION

ClinicalTrials, NCT04595240 .

Impact of COVID-19 on male urogenital health: Success of vaccines

Throughout 2021, the scientific and medical communities were concentrated on dealing with the acute morbidity and mortality induced by the COVID-19 pandemic due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We reviewed the present data for adverse effects of COVID-19 on the different parts of the male urogenital system during the dynamic situation of the COVID-19 pandemic. With the approval of COVID-19 vaccinations, there is a ray of hope at the end of this dark tunnel and a chance to look ahead for the management of long-term consequences in males with urogenital illness. A multidisciplinary investigation of these cases could provide information for establishing and optimizing treatment protocols.

Examining changes on testicular structure and sperm analysis of COVID-19 patients

This study aimed to examine the testicular functions with sperm analysis of patients with COVID‐19. The study was carried out with male patients aged between 18 and 50 years with positive RT‐PCR test and SARS‐CoV‐2 virus between December 2020 and April 2021. A total of 103 participants were included in the study. The mean age was 31.24 ± 5.67 (19–45) years and the mean body mass index of the participants was 28.41 ± 4.68 kg/m². The patients were divided into two groups, group‐1 was patients who had COVID‐19, group‐2 was healthy men. A semen analysis of both groups was performed, and the serum total testosterone, FSH, LH, anti‐mullerian hormone and Inhibin‐B tests were analysed and recorded. The testicular dimensions and testicular densities were examined by ultrasound and elastography for both groups. Comparing the patient and control groups results, this study found that the sperm count per 1 cc (p = 0.01) and total motility (p = 0.01) in group‐1 was lower than in the control group, the testicular dimensions decreased (for right testis group‐2 was 15.39 ± 4.78 ml versus group‐1 was 12.11 ± 4.62 cm³p < 0.01, for left testis group‐2 was 16.01 ± 5.12 versus group‐1 was 11.92 ± 4.78 cm³; p < 0.01), and the shear wave velocities were significantly higher in group‐1 patients. In conclusion, sperm parameters deteriorate in men who have symptomatic disease with SARS‐CoV‐2 infection. The fact that the cause of this deterioration is characterized by changes at the cellular level in the testis raises doubts about the persistence of this condition.

The Possible Role of SARS-CoV-2 in Male Fertility: A Narrative Review

The spread of severe acute respiratory syndrome—Coronavirus 2 (SARS-CoV-2) around the world has rapidly sparked the interest of the scientific community to discover its implications in human health. Many studies have suggested that SARS-CoV-2 is directly or indirectly involved in the male reproductive tract impairment. Some evidence supports the possible role of the virus in male infertility. Therefore, this review aims to summarize the relationship between the male urogenital tract, male fertility, and the gonadal hormone profile. The testis is one of the organs with the highest expression of the angiotensin-converting enzyme (ACE) 2-receptor that allows the virus to penetrate human cells. Orchitis is a possible clinical manifestation of COVID-19 and testicular damage has been found on autopsy in the testes of patients who died from the disease. SARS-CoV-2 infection can compromise the blood-testis barrier, favoring testicular damage and the production of anti-sperm autoantibodies. Some studies have detected the presence of SARS-CoV-2 in semen and a high percentage of patients with COVID-19 have altered sperm parameters compared to controls. Finally, lower testosterone levels, higher luteinizing hormone (LH) levels, and decreased follicle-stimulating (FSH)/LH and testosterone/LH ratios suggest primary testicular damage. In conclusion, further studies are needed to evaluate the exact mechanisms by which SARS-CoV-2 affects the male reproductive system and fertility and to evaluate the reversibility of its long-term effects.

Cellular and Molecular Mechanisms of In Vivo and In Vitro SARS-CoV-2 Infection: A Lesson from Human Sperm

Despite the major target of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, being the respiratory system, clinical evidence suggests that the male reproductive system may represent another viral target organ. Revealing the effect of SARS-CoV-2 infection on testis and sperm is a priority for reproductive biology, as well as for reproductive medicine. Here, we confirmed that the SARS-CoV-2 receptor angiotensin-converting enzyme 2 (ACE2) is highly expressed on human testis and ejaculated sperm; moreover, we provide evidence for the expression of the co-receptors transmembrane protease/serine (TMPRSS2), Basigin (BSG), and Catepsin L (CTSL). Human sperm were readily infected, both in vivo and in vitro, by SARS-CoV-2, as demonstrated by confocal and electron microscopy. The demonstration that the seminiferous epithelium and sperm support SARS-CoV-2 viral replication suggests the possibility that the spermatogenetic process may be detrimentally affected by the virus, and at the same time, supports the need to implement safety measures and guidelines to ensure specific care in reproductive medicine.

Research trends and hotspots of COVID-19 impact on sexual function: A bibliometric analysis based on Web of Science

Background

The outbreak of coronavirus disease 2019 (COVID-19) has brought indelible harms to the world and aroused great concern worldwide. This paper aims to analyze the impact of COVID-19 on sexual function using bibliometrics, and summarize research hotspots in this field.

Methods

Relevant publications concerning the impact of COVID-19 on sexual function in the Web of Science collection database (WoSCC) between January 1, 2020 and March 12, 2022 were screened and analyzed by bibliometric analysis using the visualization software CiteSpace and VOSviewer.

Results

Of the 1,054 publications screened, the United States (US) contributed the most (398/37.8%), followed by the United Kingdom (UK) (119/11.3%). Among all institutions, the University of Toronto in Canada enjoyed the largest number of publications (30), and Johns Hopkins University in the US enjoyed the highest frequency of citation (235). The journal INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH published the largest number of studies in this field (31), and the most-cited journal was LANCET. "Chow, Eric," "Ong, Jason J," and "Stephenson, Rob" tied for first place in publications (8), and "Fish, Jessica N." enjoyed the highest number of citations (99). Burstness analysis of references and keywords showed that the developing research trends in this field mainly focused on "sexual transmission" and "angiotensin converting-enzyme 2 (ACE2)" during the COVID-19 pandemic.

Conclusion

The impact of COVID-19 on sexual function remains an urgent concern at present, and the management of sexual health during the pandemic needs to be further improved. More frequent and deeper cooperation between countries and institutions is required in future. Meanwhile, searching for more evidence on whether COVID-19 can achieve sexual transmission and the pathophysiological mechanisms underlying the impact of COVID-19 on sexual function remains a focus of research in the coming years.

Metabolic, Oxidative and Psychological Stress as Mediators of the Effect of COVID-19 on Male Infertility: A Literature Review

Over 300 million patients with coronavirus disease 2019 (COVID-19) have been reported worldwide since the outbreak of the pandemic in Wuhan, Hubei Province, China. COVID-19 is induced by the acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The effect of SARS-CoV-2 infection on the male reproductive system is unclear. The aim of this review is to assess the effect of SARS-CoV-2 infection on male fertility and the impact of possible mediators, such as metabolic, oxidative and psychological stress. SARS-CoV-2 infection aggravates metabolic stress and directly or indirectly affects male fertility by reducing seminal health. In addition, SARS-CoV-2 infection leads to excessive production of reactive oxygen species (ROS) and increased psychological distress. These data suggest that SARS-CoV-2 infection reduces male fertility, possibly by means of metabolic, oxidative and psychological stress. Therefore, among other consequences, the possibility of COVID-19-induced male infertility should not be neglected.

COVID-19 and Male Reproduction: A Thorny Problem

With the global epidemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the increasing number of infections, little is known about how SARS-CoV-2 affects the male reproductive system during infection or after recovery. Based on the existing research data, we reviewed the effects of SARS-CoV-2 on the male reproductive system and discussed its possible mechanism of action. SARS-CoV-2 enters host cells through the angiotensin-converting enzyme 2 (ACE2)/transmembrane serine protease 2 (TMPRSS2) pathway, and males are more susceptible than females. After infection, immunopathological damage is noticed in the testicles, and the semen index is significantly reduced. Second, abnormalities of serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone (T) levels were also observed, suggesting that there may be dysfunction of the hypothalamic–pituitary–gonadal (HPG) axis. Even after recovery, the effect of SARS-CoV-2 on the male reproductive system can last for at least a period. There are still many unresolved questions about the effect of SARS-CoV-2 infection on the male reproductive tract. Other receptors involved during the invasion of human cells by SARS-CoV-2 remain to be identified. Will the mutation of SARS-CoV-2 increase the diversity of receptors? How does SARS-CoV-2 affect the HPG axis? The long-term effects of SARS-CoV-2 on the male reproductive system remain to be evaluated. SARS-CoV-2 infection can affect male reproductive function. Standard treatment strategies should be developed in time to protect the fertility of infected patients. For recovered patients with fertility requirements, fertility assessments should be performed and professional fertility guidance should be provided at the same time.

Could Lower Testosterone in Older Men Explain Higher COVID-19 Morbidity and Mortalities?

The health scourge imposed on humanity by the COVID-19 pandemic seems not to recede. This fact warrants refined and novel ideas analyzing different aspects of the illness. One such aspect is related to the observation that most COVID-19 casualties were older males, a tendency also noticed in the epidemics of SARS-CoV in 2003 and the Middle East respiratory syndrome in 2012. This gender-related difference in the COVID-19 death toll might be directly involved with testosterone (TEST) and its plasmatic concentration in men. TEST has been demonstrated to provide men with anti-inflammatory and immunological advantages. As the plasmatic concentration of this androgen decreases with age, the health benefit it confers also diminishes. Low plasmatic levels of TEST can be determinant in the infection’s outcome and might be related to a dysfunctional cell Ca²⁺ homeostasis. Not only does TEST modulate the activity of diverse proteins that regulate cellular calcium concentrations, but these proteins have also been proven to be necessary for the replication of many viruses. Therefore, we discuss herein how TEST regulates different Ca²⁺-handling proteins in healthy tissues and propose how low TEST concentrations might facilitate the replication of the SARS-CoV-2 virus through the lack of modulation of the mechanisms that regulate intracellular Ca²⁺ concentrations.