Telemedicine technologies and applications in the era of COVID-19 pandemic: A systematic review.

INTRODUCTION: Telemedicine services saw substantial surges in their use during the COVID-19 pandemic due to the lockdowns and characteristics of the pandemic. Therefore, the authors aimed to systematically review the telemedicine services provided during the COVID-19 pandemic and their potential applications. METHODS: The authors searched PubMed, Scopus, and Cochrane databases on September 14, 2021. Then, the retrieved records underwent two-step title/abstract and full-text screening processes, and the eligible articles were included for qualitative synthesis. RESULTS: The review of studies demonstrated that the telephone is listed 38 times, making it the most common technology used in telemedicine. Video conferencing is also mentioned in 29 articles, as well as other technologies: Mobile-health (n = 15), Virtual reality (n = 7). According to the findings of the present study, Tele-follow-up (n = 24), Tele-consulting (n = 20), Virtual visits (20), and Tele-monitoring (n = 18) were the most widely used telemedicine applications. CONCLUSION: Telemedicine has been an effective approach to COVID-19 management. Telemedicine technology is going to play a key role in the future of health medicine, patient consultation, and many other extended applications of health care in remote rural locations.

Post-Exposure Prophylaxis for COVID-19: A Systematic Review.

INTRODUCTION: SARS-CoV-2 cause pneumonia can spread across the lung and lead to acute respiratory distress syndrome (ARDS) in severe cases. Post-exposure prophylaxis has shown great potential to prevent the transmission of some viral infections; however, such results for COVID-19 are still inconclusive. METHODS: Therefore, the aim of this study was to systematically review the resources that utilized postexposure prophylaxis (PEP) for COVID-19 and the possible clinical benefits of such drugs. An organized search of relevant literature was done using the keywords and search queries on public databases of Cochrane, PubMed, Web of Science and Scopus from December 2019 to August 23, 2021. Original resources that had the inclusion criteria were included after two-phase title/abstract and full-text screenings. This review adhered to the Preferred Reporting Items for Systematic Reviews and MetaAnalysis (PRISMA) statement. RESULTS: Out of 841 retrieved records 17 resources were appropriate to include in the systematic review. Hydroxychloroquine with a daily dose of 400-800 mg and a duration of 5-14 days was the most frequently used agent for PEP. Chloroquine was recommended to use to control treatment in patients with mild to severe COVID-19 pneumonia. Other agents like Lopinavir-ritonavir (LPV/r), angiotensinconverting enzyme inhibitors (ACEIs), Angiotensin receptor blockers (ARBs), Vitamin D, arbidol, thymosin drugs, and Xin guan no.1 (XG.1, a Chinese formula medicine) have also been applied in some studies. CONCLUSION: Current evidence demonstrated no established clinical benefits of any drug as PEP in individuals with COVID-19. However, scarce indication occurs for the beneficial effects of some agents, but more studies are needed to explore such effects.

Abortion services during the COVID-19 pandemic: a systematic review.

Evidence suggests that COVID-19 may impair access to sexual and reproductive health services and safe abortion. The purpose of this systematic review was investigating the changes of abortion services in the COVID-19 pandemic era. We searched PubMed, Web of Science and Scopus for relevant studies published as of August 2021, using relevant keywords. RCT and non-original studies were excluded from the analysis and 17 studies of 151 included in our review. Requests to access medication abortion by telemedicine and demand for self-managed abortion were the main findings of identified studies. Women requested an abortion earlier in their pregnancy, and were satisfied with tele-abortion care due to its flexibility, and ongoing telephone support. Presenting telemedicine services without ultrasound has also been reported. Visits to clinics were reduced based on the severity of the restrictions, and abortion clinics had less revenue, more costs, and more changes in the work style of their healthcare providers. Telemedicine was reported safe, effective, acceptable, and empowering for women. Reasons for using tele-abortion were privacy, secrecy, comfort, using modern contraception, employing of women, distance from clinics, travel restrictions, lockdowns, fear of COVID-19, and political reasons (abortion prohibition). Complications of women using tele-abortion were pain, lack of psychological support, bleeding, and need to blood transfusions. The results of this study showed that using telemedicine and teleconsultations for medical abortion in the pandemic conditions may be extended after pandemic. Findings can be used by reproductive healthcare providers and policy makers to address the complications of abortion services.Trail registration This study is registered in PROSPERO with number CRD42021279042.

COVID-19 pandemic shocks the international community, especially health policymakers around the world. The most important consequence of this outbreak has been direct and indirect impacts on health service provisions in all parts of the health system, including sexual and reproductive health services. We reviewed numerous studies investigating healthcare related to abortion in the pandemic era that showed women had more requests to access medical abortion, more than surgical. They preferred self-managed abortion process by telemedicine. Presenting telemedicine services without ultrasound has also been reported. Visits to clinics were reduced, and this decrease was reported based on the severity of the restrictions. Abortion clinics had reduced revenue, increased costs, and changed work style of their healthcare providers. Reasons for using telemedicine were fear of COVID-19, travel restrictions, lockdowns, more privacy, secrecy, and comfort. Telemedicine was reported safe, effective, acceptable, satisfying, and empowering for women. Maternal complications using tele-abortion were pain, bleeding, and need to blood transfusions. These findings can be used by policy makers and reproductive healthcare providers to address the complications of abortion management.

The relationship between sex steroids (E2, progesterone, and AMH) levels and severity and fatality of COVID-19: A systematic review

Sex steroids are powerful modulators of the immune system and they may affect the immune response and inflammatory consequences of COVID-19. This systematic review aims to explore the impact of sex steroids on COVID-19 mortality and complications. We looked up the keywords of the study in Scopus, PubMed, and Web of Science. All related original articles published in English, as of October 16, 2021, were reviewed to be included in our research. Concerns regarding the effect of sex hormones on COVID-19, eight full texts have been identified for the conclusion. In these studies, the relationship between estradiol and COVID-19 mortality has been mentioned. The most significant findings were the higher COVID-19 mortality rate in men, compared to women;also, in menopausal women compared to younger women and who received estradiol. In two studies, oral contraceptive pills had a protective effect on the morbidity of SARS-CoV-2 infection. In a randomized controlled trial, subcutaneous injection of progesterone in hospitalized men significantly reduced their symptoms and need for oxygen therapy. Hormone replacement therapy was positively associated with reducing COVID-19 symptoms. Although the results were insufficient for a conclusion, this study represents estrogen as an appropriate pharmacological method for preventing and diminishing the inflammation related to COVID-19 disease. However, future prospective studies and clinical trials are needed to clarify and approve this protective effect.

Changes in sexual activities, function, and satisfaction during the COVID-19 pandemic era: a systematic review and meta-analysis.

Introduction: Little is known about the impact of the coronavirus on sexual behavior, function, and satisfaction. Aim: The aim of the present study was to systematically review people's sexual function and behaviors and their changes in sexual activities during the COVID-19 pandemic. Methods: Comprehensive searches in PubMed, Web of Science, and Scopus were conducted with keywords in accordance with MeSH terms: COVID-19, SARS-CoV-2, coronavirus, sexual health, sexual function, sexual dysfunctions, sexuality, sexual orientation, sexual activities, and premarital sex. Two reviewers independently assessed full-text articles according to predefined criteria: original design, English studies, and investigating either the general population or sexual minorities. Results: Risk of bias in the studies was assessed by the Newcastle-Ottawa Scale, and data were pooled via random effects meta-analyses. We utilized the standardized mean difference to evaluate the effects of the COVID-19 pandemic on sexual activity, functioning, and satisfaction. We included 19 studies in the analysis and 11 studies in the meta-analysis, with a sample size of 12 350. To investigate sexual activity changes, a sample size of 8838 was entered into the subgroup analysis, which showed a significant decrease in both genders (5821 women, P < .033; 3017 men, P < .008). A subgroup meta-analysis showed that the sexual function of men and women during the COVID-19 pandemic significantly declined (3974 women, P < .001; 1427 men, P < .001). Sexual desire and arousal decreased in both genders, though mainly in women. In investigating sexual satisfaction changes during the COVID-19 pandemic, a meta-analysis with a sample size of 2711 showed a significant decrease (P < .001). The most indicative changes in sexual behaviors during the pandemic were the increase in masturbating and usage of sex toys. Greater COVID-19 knowledge was associated with lower masturbation, oral sex, and vaginal sex. The more protective behaviors were associated with less hugging, kissing, cuddling, genital touching, watching porn with a partner, and vaginal sex. Conclusion: The COVID-19 pandemic led to increased challenges and changes for individuals' sexual behaviors. Efforts for preventive strategies should therefore be concentrated between pandemics, while ensuring that there is information available to the population during a pandemic for help in times of psychological distress or crisis.

The relationship between sex steroids (E2, progesterone, and AMH) levels and severity and fatality of COVID-19: A systematic review.

Sex steroids are powerful modulators of the immune system and they may affect the immune response and inflammatory consequences of COVID-19. This systematic review aims to explore the impact of sex steroids on COVID-19 mortality and complications. We looked up the keywords of the study in Scopus, PubMed, and Web of Science. All related original articles published in English, as of October 16, 2021, were reviewed to be included in our research. Concerns regarding the effect of sex hormones on COVID-19, eight full texts have been identified for the conclusion. In these studies, the relationship between estradiol and COVID-19 mortality has been mentioned. The most significant findings were the higher COVID-19 mortality rate in men, compared to women; also, in menopausal women compared to younger women and who received estradiol. In two studies, oral contraceptive pills had a protective effect on the morbidity of SARS-CoV-2 infection. In a randomized controlled trial, subcutaneous injection of progesterone in hospitalized men significantly reduced their symptoms and need for oxygen therapy. Hormone replacement therapy was positively associated with reducing COVID-19 symptoms. Although the results were insufficient for a conclusion, this study represents estrogen as an appropriate pharmacological method for preventing and diminishing the inflammation related to COVID-19 disease. However, future prospective studies and clinical trials are needed to clarify and approve this protective effect.

Minimum infective dose of severe acute respiratory syndrome coronavirus 2 based on the current evidence: A systematic review.

Objective: Understanding the minimum infective dose is significant for risk assessment in the performance of suitable infection control strategies in healthcare centers. However, the literature lacks strong evidence regarding this value for severe acute respiratory syndrome coronavirus 2. Therefore, the aim of this study was to investigate the minimum infectious dose of coronavirus disease 2019. Methods: We searched the databases of PubMed, Scopus, Web of Science, and Cochrane and retrieved all the relevant literature by 25 July 2021. The records were downloaded into the EndNote software and underwent title/abstract and full-text screenings. A summary of included studies was organized into tables for further analysis, interpretation, and drafting of the results. Results: Nineteen studies including the laboratory data on human and animal hosts were selected based on the eligibility criteria. All the literature reported on the infective dose, particularly in humans. The main methods for measurement of infection were through tissue culture infectious dose (TCID50) and counting plaque-forming units. The range of minimum infective was 1.26-7 × 106.25 PFU. Conclusion: In this study, we have presented a range of minimum infective doses in humans and various animal species. Such numbers can possibly vary between the individuals based on numerous demographic, immunologic, or other factors.

Virtual clinic in pregnancy and postpartum healthcare: A systematic review.

Background and Aims: To monitor the health status of pregnant women moment by moment, new technologies in the field of telemedicine can be used, such as virtual visits and virtual clinics. During the COVID-19 pandemic, by using these technologies, useful and satisfactory services have been provided to pregnant mothers. The aim of this study is to specify the applications, features, and infrastructure of a comprehensive virtual clinic in the field of gynecological and pregnancy care. Methods: A systematic review search was conducted through the scientific databases from February 2013 to February 2022 using Scopus, Web of Science, and PubMed. Furthermore, manual searches in Google Scholar and the reference lists of included studies were carried out. Results: In this systematic review we included 16 articles that reported experiences in virtual clinics in pregnancy and postpartum healthcare. The involved studies were experimental, cohort, and cross-sectional studies. The target group users were pregnant or women who gave birth and families of neonatal. The application of virtual clinics was for the visit, consultation, monitoring, follow-up, and home care virtually. Highly satisfaction scores of caregivers after virtual visits and consultation were reported. There were some challenges during virtual visits and consultation; the most important challenge was a poor internet connection. Conclusion: The reviewed studies show promising outcomes according to patient and provider satisfaction. We predict that telehealth will become a growingly significant part of gynecological care in the future.

Minimum infective dose of severe acute respiratory syndrome coronavirus 2 based on the current evidence: A systematic review

Objective: Understanding the minimum infective dose is significant for risk assessment in the performance of suitable infection control strategies in healthcare centers. However, the literature lacks strong evidence regarding this value for severe acute respiratory syndrome coronavirus 2. Therefore, the aim of this study was to investigate the minimum infectious dose of coronavirus disease 2019. Methods: We searched the databases of PubMed, Scopus, Web of Science, and Cochrane and retrieved all the relevant literature by 25 July 2021. The records were downloaded into the EndNote software and underwent title/ and full-text screenings. A summary of included studies was organized into tables for further analysis, interpretation, and drafting of the results. Results: Nineteen studies including the laboratory data on human and animal hosts were selected based on the eligibility criteria. All the literature reported on the infective dose, particularly in humans. The main methods for measurement of infection were through tissue culture infectious dose (TCID50) and counting plaque-forming units. The range of minimum infective was 1.26–7 × 106.25 PFU. Conclusion: In this study, we have presented a range of minimum infective doses in humans and various animal species. Such numbers can possibly vary between the individuals based on numerous demographic, immunologic, or other factors.

Safety and Adverse Events Related to Inactivated COVID-19 Vaccines and Novavax;a Systematic Review.

Introduction: Knowledge of the safety of vaccines is crucial, both to prevent and cure them and to decrease the public hesitation in receiving vaccines. Therefore, this study aimed to systematically review the adverse events reported for inactivated vaccines and Novavax. Methods: In this systematic review, the databases of PubMed, Scopus, Cochrane, and Web of Science were searched on September 15, 2021. Then we identified the eligible studies using a two-step title/abstract and full-text screening process. Data on the subjects, studies, and types of adverse events were extracted and entered in a word table, including serious, mild, local, and systemic adverse events as well as the timing of side effects' appearance. Results: Adverse effects of inactivated coronavirus vaccines side effects were reported from phases 1, 2, and 3 of the vaccine trials. The most common local side effects included injection site pain and swelling, redness, and pruritus. Meanwhile, fatigue, headache, muscle pain, fever, and gastrointestinal symptoms including abdominal pain and diarrhea were among the most common systemic adverse effects. Conclusion: This systematic review indicates that inactivated COVID-19 vaccines, including Sinovac, Sinopharm, and Bharat Biotech, as well as the protein subunit vaccines (Novavax) can be considered as safe choices due to having milder side effects and fewer severe life-threatening adverse events.

Safety and Adverse Events Related to COVID-19 mRNA Vaccines; a Systematic Review.

Introduction: Knowledge of vaccine-related adverse events is crucial as they are among the most important factors that cause hesitation in receiving vaccines. Therefore, we aimed to systematically review the adverse events related to the mRNA vaccines reported in the literature. . Method: A systematic literature search was carried out in the databases of Scopus, PubMed, Cochrane, and Web of Science. We selected original studies that explored the side effects of mRNA COVID-19 vaccines using a two-phase (title/abstract and full-text) screening process. . Results: Cardiac complications were the most commonly reported severe adverse events. It appeared that systemic adverse reactions are more common after the second dose of vaccines. The number of adverse effects reported after the Pfizer vaccine was higher than other vaccines, mostly due to its earlier approval and more widespread use throughout the world. Cardiac adverse events had a higher prevalence but no significant association has been found between COVID-19 mRNA vaccines and cardiac adverse events except for myopericarditis. . Conclusion: Vaccines play a crucial role in controlling the COVID-19 pandemic and decreasing mortalities and the results of the present review acknowledge the fact that the benefits outweigh the adverse events of these vaccines. .

COVID-19 mortality and its predictors in the elderly: A systematic review.

Background and Aims: Older people have higher rates of comorbidities and may experience more severe inflammatory responses; therefore, are at higher risk of death. Herein, we aimed to systematically review the mortality in coronavirus disease 2019 (COVID-19) patients and its predictors in this age group. Methods: We searched PubMed, Web of Science, and Science Direct using relevant keywords. Retrieved records underwent a two-step screening process consisting of title/abstract and full-text screenings to identify the eligible studies. Results: Summarizing findings of 35 studies demonstrated that older patients have higher mortality rates compared to the younger population. A review of articles revealed that increasing age, body mass index, a male gender, dementia, impairment or dependency in daily activities, presence of consolidations on chest X-ray, hypoxemic respiratory failure, and lower oxygen saturation at admission were risk factors for death. High d-dimer levels, 25-hydroxy vitamin D serum deficiencies, high C-reactive protein (≥5 mg/L) levels plus any other abnormalities of lymphocyte, higher blood urea nitrogen or lactate dehydrogenase, and higher platelet count were predictors of poor prognosis and mortality in the elderly. Studies have also shown that previous treatment with renin-angiotensin-aldosterone system inhibitors, pharmacological treatments of respiratory disorders, antibiotics, corticosteroids, vitamin K antagonist, antihistamines, azithromycin, Itolizumab (an anti-CD6 monoclonal antibody) in combination with other antivirals reduces COVID-19 worsening and mortality. Vaccination against seasonal influenza might also reduce COVID-19 mortality. Conclusion: Overall, a critical consideration is necessary for the care and management of COVID-19 in the aged population considering the drastic contrasts in manifestation and prognosis compared to other age groups. Mortality from COVID-19 is independently associated with the patient's age. Elderly patients with COVID-19 are more vulnerable to poor outcomes. Thus, strict preventive measures, timely diagnosis, and aggressive therapeutic/nontherapeutic care are of great importance to reduce acute respiratory distress syndrome and severe complications in older people.

COVID‐19 mortality and its predictors in the elderly: A systematic review

Background and AimsOlder people have higher rates of comorbidities and may experience more severe inflammatory responses;therefore, are at higher risk of death. Herein, we aimed to systematically review the mortality in coronavirus disease 2019 (COVID‐19) patients and its predictors in this age group.MethodsWe searched PubMed, Web of Science, and Science Direct using relevant keywords. Retrieved records underwent a two‐step screening process consisting of title/ and full‐text screenings to identify the eligible studies.ResultsSummarizing findings of 35 studies demonstrated that older patients have higher mortality rates compared to the younger population. A review of articles revealed that increasing age, body mass index, a male gender, dementia, impairment or dependency in daily activities, presence of consolidations on chest X‐ray, hypoxemic respiratory failure, and lower oxygen saturation at admission were risk factors for death. High d‐dimer levels, 25‐hydroxy vitamin D serum deficiencies, high C‐reactive protein (≥5 mg/L) levels plus any other abnormalities of lymphocyte, higher blood urea nitrogen or lactate dehydrogenase, and higher platelet count were predictors of poor prognosis and mortality in the elderly. Studies have also shown that previous treatment with renin–angiotensin–aldosterone system inhibitors, pharmacological treatments of respiratory disorders, antibiotics, corticosteroids, vitamin K antagonist, antihistamines, azithromycin, Itolizumab (an anti‐CD6 monoclonal antibody) in combination with other antivirals reduces COVID‐19 worsening and mortality. Vaccination against seasonal influenza might also reduce COVID‐19 mortality.ConclusionOverall, a critical consideration is necessary for the care and management of COVID‐19 in the aged population considering the drastic contrasts in manifestation and prognosis compared to other age groups. Mortality from COVID‐19 is independently associated with the patient's age. Elderly patients with COVID‐19 are more vulnerable to poor outcomes. Thus, strict preventive measures, timely diagnosis, and aggressive therapeutic/nontherapeutic care are of great importance to reduce acute respiratory distress syndrome and severe complications in older people.

Public acceptability of COVID-19 vaccines and its predictors in Middle Eastern/North African (MENA) countries: a systematic review .

INTRODUCTION: COVID-19 vaccines emerged as a worldwide hope to contain the pandemic. However, many people are still hesitant to receive these vaccines. We aimed to systematically review the public knowledge, perception, and acceptability of COVID-19 vaccines in the Middle East and North Africa (MENA) countries and the predictors of vaccine acceptability in this region. METHODS: We systematically searched databases of PubMed, Scopus, Web of Science, and Cochrane and retrieved all relevant studies by 5 August 2021. RESULTS: There was a considerable variation in the COVID-19 vaccine acceptance rates, from 12% in a study from Israel to 83.3% in Kuwait, although two other studies from Israel mentioned 75% and 82.2% acceptability rates. Concerns about the side effects and safety of the vaccine were the main reasons for the lack of acceptability of taking the vaccine, which was reported in 19 studies. . CONCLUSION: Several factors, such as age, gender, education level, and comorbidities, are worthy of attention as they could expand vaccine coverage in the target population. .

Internet of things in the management of chronic diseases during the COVID-19 pandemic: A systematic review.

Introduction: The use of new technologies such as the Internet of Things (IoT) in the management of chronic diseases, especially in the COVID pandemics, could be a life-saving appliance for public health practice. The purpose of the current study is to identify the applications and capability of IoT and digital health in the management of the COVID-19 pandemic. Methods: This systematic review was conducted by searching the online databases of PubMed, Scopus, and Web of Science using selected keywords to retrieve the relevant literature published until December 25th, 2021. The most relevant original English studies were included after initial screening based on the inclusion criteria. Results: Overall, 18 studies were included. Most of the studies reported benefits and positive responses in the form of patients' and healthcare providers' satisfaction and trust in the online systems. Many services were provided to the patients, including but not limited to training the patients on their conditions; monitoring vital signs and required actions when vital signs were altered; ensuring treatment adherence; monitoring and consulting the patients regarding diet, physical activity, and lifestyle. Conclusion: IoT is a new technology, which can help us improve health care services during the COVID-19 pandemic. It has a network of various sensors, obtaining data from patients. We have found several applications for this technology. Future studies can be conducted for the capability of other technologies in the management of chronic diseases.

Cutaneous adverse reactions of COVID-19 vaccines: A systematic review.

Numerous vaccines are under clinical development and implementation for the prevention of severe course and lethal outcomes of coronavirus disease 2019 (COVID-19). This systematic review aims to summarize and integrated the findings of studies regarding cutaneous side effects of COVID-19 vaccines. This systematic review conducted by searching the scientific databases of PubMed, Scopus, Science direct, and Web of knowledge from the beginning of the COVID-19 to May 10, 2021. Articles were reviewed and analyzed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Seventeen studies on cutaneous side effects of COVID-19 vaccines were included after the screening of search results based on to the eligibility criteria. The results showed that the most common injection site reactions and delayed large local reactions, arising from all vaccine types, were redness/erythema (39%), followed by: itchiness (28%), urticarial rash (17%) on the neck, upper limbs, and trunk, morbilliform eruptions (6.5%), Pityriasis rosea (3%), swelling, and burning, and so forth. Most cutaneous reactions occurred in women (84%), and middle-aged people, after the first dose of vaccine, with the onset ranged from 1 to 21 days after vaccination. In addition, cutaneous reactions were generally self-limiting, and needed little or no therapeutic intervention, that were not regarded as a barrier to injecting a second dose. In conclusion, severe cutaneous side effects are very rare and approved vaccines have satisfactory safety profiles. Therefore, mild or moderate cutaneous reactions should not discourage people from vaccination. In certain groups such as patients with allergies and a history of local injection reactions, pre-vaccination counseling and assurance, also use of appropriate medications may be helpful. However, more studies are needed to investigate the side effect profile of all COVID-19 vaccines.

Impact of COVID-19 pandemic on routine vaccination coverage of children and adolescents: A systematic review.

BACKGROUND AND AIMS: Scientists and healthcare workers have expressed their concerns on the impacts of the COVID-19 pandemic on vaccination coverage in children and adolescents. Therefore, we aimed to systematically review the studies addressing this issue worldwide. METHODS: We conducted a systematic search of relevant studies using the keywords on databases of PubMed, Web of Science, and Cochrane on May 22, 2021. The identified records were imported into EndNote software and underwent a two-phase screening process consisting of title/abstract and full-text screenings against inclusion criteria. The data of the included studies were summarized into a table and the findings were analyzed in a systematic approach. RESULTS: From 26 eligible studies, 21 studies demonstrated decreased vaccination rates in the children during the COVID-19 pandemic, while three studies found increased or no significant changes only in influenza vaccination. The two remaining studies from Brazil and Sweden also showed no significant changes in vaccination rates in the children during the pandemic. CONCLUSION: Most of the reports worldwide reported a decline or delay in vaccination at the time of the COVID-19 pandemic. A sustained catch-up program seems to be necessary, especially in low-income countries, to avoid any vaccine dose missing. Facilitating the vaccination process is recommended, such as decreasing the waiting time for vaccination at the health center, addressing the fear and concerns related to COVID infection for parents, and enhancing vaccine availability, and promoting access in remote areas. Countries should ensure proper vaccination to prevent future pandemics related to vaccine-preventable diseases.

Characterization of SARS-CoV-2 different variants and related morbidity and mortality: a systematic review.

INTRODUCTION: Coronavirus Disease-2019 (SARS-CoV-2) started its devastating trajectory into a global pandemic in Wuhan, China, in December 2019. Ever since, several variants of SARS-CoV-2 have been identified. In the present review, we aimed to characterize the different variants of SARS-CoV-2 and explore the related morbidity and mortality. METHODS: A systematic review including the current evidence related to different variants of SARS-CoV-2 and the related morbidity and mortality was conducted through a systematic search utilizing the keywords in the online databases including Scopus, PubMed, Web of Science, and Science Direct; we retrieved all related papers and reports published in English from December 2019 to September 2020. RESULTS: A review of identified articles has shown three main genomic variants, including type A, type B, and type C. we also identified three clades including S, V, and G. Studies have demonstrated that the C14408T and A23403G alterations in the Nsp12 and S proteins are the most prominent alterations in the world, leading to life-threatening mutations.The spike D614G amino acid change has become the most common variant since December 2019. From missense mutations found from Gujarat SARS-CoV-2 genomes, C28854T, deleterious mutation in the nucleocapsid (N) gene was significantly associated with patients' mortality. The other significant deleterious variant (G25563T) is found in patients located in Orf3a and has a potential role in viral pathogenesis. CONCLUSION: Overall, researchers identified several SARS-CoV-2 variants changing clinical manifestations and increasing the transmissibility, morbidity, and mortality of COVID-19. This should be considered in current practice and interventions to combat the pandemic and prevent related morbidity and mortality.