Immunogenicity and Safety of Homologous Booster Doses of CoronaVac COVID-19 Vaccine in Elderly Individuals Aged 60 Years and Older: A Dosing Interval Study - Yunnan Province, China, 2021-2022.

What is already known about this topic?: Neutralization levels induced by inactivated vaccines rapidly wane after primary immunization, and a homologous booster can recall specific immune memory, resulting in a remarkable increase in antibody concentration. The optimal interval between primary and booster doses has yet to be determined. What is added by this report?: Booster doses given at three months or more after the two-dose regimen of the CoronaVac COVID-19 vaccine in elderly individuals aged 60 years and older triggered good immune responses. The geometric mean titers of neutralizing antibody on Day 14 after the booster doses increased by 13.3-26.2 fold of baseline levels, reaching 105.45-193.59 in groups with different intervals (e.g., 3, 4, 5, and 6 months). What are the implications for public health practice?: A 4- to 5-month interval between receiving the primary and booster series of CoronaVac could be an alternative to the 6-month interval in order to promote vaccine-induced immunity in elderly individuals. The findings support the optimization of booster immunization strategies.

Association between COVID-19 and Male Fertility: Systematic Review and Meta-Analysis of Observational Studies.

PURPOSE: Whether COVID-19 reduces male fertility remains requires further investigation. This meta-analysis and systematic review evaluated the impact of COVID-19 on male fertility. MATERIALS AND METHODS: The literature in PubMed, Embase, MEDLINE, Web of Science, and Cochrane Library up to January 01, 2022 was systematically searched, and a meta-analysis was conducted to investigate the effect of COVID-19 on male fertility. Totally 17 studies with a total of 1,627 patients and 1,535 control subjects were included in our meta-analysis. RESULTS: Regarding sperm quality, COVID-19 decreased the total sperm count (p=0.012), sperm concentration (p=0.001), total motility (p=0.001), progressive sperm motility (p=0.048), and viability (p=0.031). Subgroup analyses showed that different control group populations did not change the results. It was found that during the illness stage of COVID-19, semen volume decreased, and during the recovery stage of COVID-19, sperm concentration and total motility decreased <90 days. We found that sperm concentration and total motility decreased during recovery for ≥90 days. Fever because of COVID-19 significantly reduced sperm concentration and progressive sperm motility, and COVID-19 without fever ≥90 days, the sperm total motility and progressive sperm motility decreased. Regarding disease severity, the moderate type of COVID-19 significantly reduced sperm total motility, but not the mild type. Regarding sex hormones, COVID-19 increased prolactin and estradiol. Subgroup analyses showed that during the illness stage, COVID-19 decreased testosterone (T) levels and increased luteinizing hormone levels. A potential publication bias may have existed in our meta-analysis. CONCLUSIONS: COVID-19 in men significantly reduced sperm quality and caused sex hormone disruption. COVID-19 had long-term effects on sperm quality, especially on sperm concentration and total motility. It is critical to conduct larger multicenter studies to determine the consequences of COVID-19 on male fertility.

Boronic acid-modified bacterial cellulose microspheres as packing materials for enveloped virus removal.

Viruses are the most abundant microorganisms on the earth, their existence in contaminated waters possesses a significant threat to humans. Waterborne viral infections could be fatal to sensitive population including young child, the elderly, and the immune-compromised. It is imperative to remove viruses during water treatment to better protect public health, especially in the light of evidence of detection of coronaviruses genetic fragments in raw sewage. We reported bench-scale experiments evaluating the extent and mechanisms of removal of a model virus (spring viremia of carp virus, SVCV) in water by adsorption. Microspheres made by boronic acid-modified bacterial cellulose with excellent mechanical strength were successfully fabricated as packing materials for the column to remove glycoproteins and enveloped viruses from water. The synthesized adsorbent was characterized by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), and Brunauer Emmett Teller (BET) measurement. The adsorption efficiency of glycoproteins was investigated by SDS-PAGE and the Broadford protein assay, while the binding capacity with the virus (spring viremia of carp virus) was monitored by cell culture to calculate the viral cytopathic effect and viral titer caused by the virus. The data obtained from the above experiments showed that ∼3-log removal of SVCV in 3 h, which significantly reduced the virus concentration from microspheres packed column. The present study provides substantial evidence to prove beyond doubt that material based on bacterial cellulose seems to have the potential for virus removal from water which can be extended to systems of significant importance.

Safety of primary immunization using inactivated SARS-CoV-2 vaccine (CoronaVac®) among population aged 3 years and older in a large-scale use: A multi-center open-label study in China.

OBJECTIVE: To evaluate the safety of primary immunization using CoronaVac® among population aged 3 years and above in a large-scale use. METHOD: A multi-center open-label study was carried out in 11 provinces of China. Individuals aged 3 years and older who had no history of COVID-19 vaccination or had received only one dose of CoronaVac® were enrolled in this study. Adults and elderly with or without underlying medical conditions(UMCs) were also recruited. Eligible participants received one or two doses of CoronaVac® with an interval of 28 days. Demographic information, vaccination and the occurrence of adverse events were recorded by participants or guardians using data collection system designed for this study. All adverse events occurred within 6 months after the second dose of vaccination were collected. The incidence of adverse events that cannot be ruled out as being caused by the vaccine were calculated to assess the safety of CoronaVac®. This study is registered with ClinicalTrials. Gov (NCT04911790 and NCT04992208). RESULTS: A total of 162,691 participants have been included in this study and 89.50 % had finished primary immunization. Among adults and elderly, people with UMCs accounted for 25.85 %, with the top five disease being hypertension, diabetes, chronic gastritis, coronary heart disease(CHD) and kidney stone. The overall incidence of adverse reactions (ARs) within 6 months after the second vaccination was 2.70 %, with incidence for children and adolescents, adults, and elderly being 2.03 %, 3.46 %, and 1.90 %, respectively. Most ARs were mild (grade 1). Pain at the injection sites, fatigue, induration/swelling, and headache were the most common symptoms, occurring in 1.64 %, 0.46 %, 0.31 % and 0.24 %, respectively. No serious adverse events related to vaccines were reported. No adverse events of special interest (AESIs) were identified. For children and adolescents, children aged 3-5 years had the highest incidence of ARs of 3.29 %. The incidence of ARs among those aged 18 years and older with and without UMCs were 2.81 % and 2.99 %, respectively, with no statistical significance between two groups(P = 0.089). And people with coronary heart disease had higher AR incidence compared to those with other UMCs, but the most common symptoms was pain at the injection site. CONCLUSION: CoronaVac® is safe in a large-scale use and shows well-tolerance for children and adolescents and people with underlying medical conditions. Further studies need to be conducted to explore the relation of ARs incidence to age or different kinds of UMCs.

Mechanisms of SARS-CoV-2 Infection-Induced Kidney Injury: A Literature Review.

The severe acute respiratory coronavirus 2 (SARS-CoV-2) has become a life-threatening pandemic. Clinical evidence suggests that kidney involvement is common and might lead to mild proteinuria and even advanced acute kidney injury (AKI). Moreover, AKI caused by coronavirus disease 2019 (COVID-19) has been reported in several countries and regions, resulting in high patient mortality. COVID-19-induced kidney injury is affected by several factors including direct kidney injury mediated by the combination of virus and angiotensin-converting enzyme 2, immune response dysregulation, cytokine storm driven by SARS-CoV-2 infection, organ interactions, hypercoagulable state, and endothelial dysfunction. In this review, we summarized the mechanism of AKI caused by SARS-CoV-2 infection through literature search and analysis.

Gender and Ethnic Disparities of Acute Kidney Injury in COVID-19 Infected Patients: A Literature Review.

Coronavirus disease 2019(COVID-19) has become a public health emergency of concern worldwide. COVID-19 is a new infectious disease arising from Coronavirus 2 (SARS-CoV-2). It has a strong transmission capacity and can cause severe and even fatal respiratory diseases. It can also affect other organs such as the heart, kidneys and digestive tract. Clinical evidence indicates that kidney injury is a common complication of COVID-19, and acute kidney injury (AKI) may even occur in severely ill patients. Data from China and the United States showed that male sex, Black race, the elderly, chronic kidney disease, diabetes, hypertension, cardiovascular disease, and higher body mass index are associated with COVID-19-induced AKI. In this review, we found gender and ethnic differences in the occurrence and development of AKI in patients with COVID-19 through literature search and analysis. By summarizing the mechanism of gender and ethnic differences in AKI among patients with COVID-19, we found that male and Black race have more progress to COVID-19-induced AKI than their counterparts.

Randomized, Double-Blinded, Placebo-Controlled Phase 2 Trial of an Inactivated Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine in Healthy Adults.

BACKGROUND: We evaluated an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine for immunogenicity and safety in adults aged 18-59 years. METHODS: In this randomized, double-blinded, controlled trial, healthy adults received a medium dose (MD) or a high dose (HD) of the vaccine at an interval of either 14 days or 28 days. Neutralizing antibody (NAb) and anti-S and anti-N antibodies were detected at different times, and adverse reactions were monitored for 28 days after full immunization. RESULTS: A total of 742 adults were enrolled in the immunogenicity and safety analysis. Among subjects in the 0, 14 procedure, the seroconversion rates of NAb in MD and HD groups were 89% and 96% with geometric mean titers (GMTs) of 23 and 30, respectively, at day 14 and 92% and 96% with GMTs of 19 and 21, respectively, at day 28 after immunization. Anti-S antibodies had GMTs of 1883 and 2370 in the MD group and 2295 and 2432 in the HD group. Anti-N antibodies had GMTs of 387 and 434 in the MD group and 342 and 380 in the HD group. Among subjects in the 0, 28 procedure, seroconversion rates for NAb at both doses were both 95% with GMTs of 19 at day 28 after immunization. Anti-S antibodies had GMTs of 937 and 929 for the MD and HD groups, and anti-N antibodies had GMTs of 570 and 494 for the MD and HD groups, respectively. No serious adverse events were observed during the study period. CONCLUSIONS: Adults vaccinated with inactivated SARS-CoV-2 vaccine had NAb as well as anti-S/N antibody and had a low rate of adverse reactions. CLINICAL TRIALS REGISTRATION: NCT04412538.

Impact of SARS-CoV-2 on Male Reproductive Health: A Review of the Literature on Male Reproductive Involvement in COVID-19.

Coronavirus Disease 2019 (COVID-19) has created a global pandemic. Global epidemiological results show that elderly men are susceptible to infection of COVID-19. The difference in the number of cases reported by gender increases progressively in favor of male subjects up to the age group ≥60-69 (66.6%) and ≥70-79 (66.1%). Through literature search and analysis, we also found that men are more susceptible to SARS-CoV-2 infection than women. In addition, men with COVID-19 have a higher mortality rate than women. Male represents 73% of deaths in China, 59% in South Korea, and 61.8% in the United States. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the pathogen of COVID-19, which is transmitted through respiratory droplets, direct and indirect contact. Genomic analysis has shown that SARS-CoV-2 is 79% identical to SARS-CoV, and both use angiotensin-converting enzyme 2 (ACE2) as the receptor for invading cells. In addition, Transmembrane serine protease 2 (TMPRSS2) can enhance ACE2-mediated virus entry. However, SARS-CoV-2 has a high affinity with human ACE2, and its consequences are more serious than other coronaviruses. ACE2 acts as a "gate" for viruses to invade cells and is closely related to the clinical manifestations of COVID-19. Studies have found that ACE2 and TMPRSS2 are expressed in the testis and male reproductive tract and are regulated by testosterone. Mature spermatozoon even has all the machinery required to bind SARS-CoV-2, and these considerations raise the possibility that spermatozoa could act as potential vectors of this highly infectious disease. This review summarizes the gender differences in the pathogenesis and clinical manifestations of COVID-19 and proposes the possible mechanism of orchitis caused by SARS-CoV-2 and the potential transmission route of the virus. In the context of the pandemic, these data will improve the understanding of the poor clinical outcomes in male patients with COVID-19 and the design of new strategies to prevent and treat SARS-CoV-2 infection.

Learner behaviors in synchronous online prosthodontic education during the 2020 COVID-19 pandemic.

STATEMENT OF PROBLEM: Synchronous online prosthodontic courses became a popular learning mode during the 2020 COVID-19 pandemic crisis. Nonetheless, the extent of learner participation and completion of these courses remains unknown. PURPOSE: The purpose of this study was to assess learner behaviors in synchronous online prosthodontic continuing education lectures in China during the 2020 COVID-19 pandemic. MATERIAL AND METHODS: All live online prosthodontic courses held by an online dental school in China from February to May 2020 were retrieved. The no-cost lectures could be accessed anonymously and viewed repeatedly on the day of broadcast. Learning behavior data (teacher speaking time, audience total, timing of first visit to the online classroom, viewing time, and completion rate) were obtained. Learning progress was calculated by dividing viewing time by teacher speaking time. When a learner progressed through 95% of a lecture, the lecture was considered completed. RESULTS: A total of 41 781 learners participated in 18 online prosthodontic courses, which had a mean duration of 77.2 ±15.8 minutes. For each lecture, 2321 ±1454 participants attended, with 510 ±404 participants completing each session. There were 13 098 participants (31.35%) who viewed the lectures for less than 1 minute. Approximately half of the participants viewed the lectures for less than 10 minutes, with their learning progress failing to pass 10%. The average completion rate was 21.97%, with variation in completion rate dependent on when a learner first visited the online classroom. Significant differences were found among the lecture completion rates and the timing of the first visit to the online classroom (P<.001). CONCLUSIONS: Synchronous online prosthodontic education courses in China had a high number of participants but low learning progress and completion rates during the 2020 COVID-19 pandemic.

Urologists and the Novel Coronavirus Disease 2019 (COVID-19): a Urologist's Perspective from China.

No need for letter to the editor.

Impact of COVID-19 epidemic on live online dental continuing education.

INTRODUCTION: This study aimed to assess live online dental continuing education during COVID-19 epidemic in China. METHODS: Twenty-one institutions providing live online dental courses in China during COVID-19 epidemic enrolled in this study. Their online and/or offline course provision before and during the epidemic was retrospectively inquired. If live online education was provided, the number of courses, duration and number of participants per week were further investigated. Time distributions of live online dental courses were recorded and classified as within working time and out of working time. The test period of COVID-19 epidemic was for two weeks between 16 February and 29 February 2020. The control period of pre-COVID-19 epidemic was for ten weeks between 01 November 2019 and 09 January 2020. RESULTS: The percentages of offline and online courses provided by 21 dental continuing education institutions before COVID-19 epidemic were 95.2% (20 out of 21) and 28.6% (6 out of 21), respectively. All the institutions suspended offline courses whilst providing two live online courses, on average, per week with 188 minutes duration and 7290 participants during the epidemic. The total number of online courses for 10 weeks before the epidemic was 33, and that for two weeks during the epidemic was 119. The proportion of courses provided within working time raised from 6.1% (2 out of 33) of pre-COVID-19 to 46.2% (55 out of 119) during COVID-19. There were significant differences between before and during the epidemic (P < .001). CONCLUSION: The dental continuing education transferred from offline to online dramatically, and live online dental continuing education increased significantly during COVID-19 epidemic in China.

Health services provision of 48 public tertiary dental hospitals during the COVID-19 epidemic in China.

OBJECTIVES: To assess the status of health services provision of public tertiary dental hospitals during the COVID-19 epidemic in China and to evaluate the regional difference of telehealth. MATERIALS AND METHODS: The health services provision of public tertiary dental hospitals in China mainland during the COVID-19 epidemic was inquired. The status of non-emergency dental services, emergency dental services, and online professional consultation and the hospitals' geographical distribution were recorded and analyzed. RESULTS: All the 48 public tertiary dental hospitals suspended general non-emergency dental treatment while providing emergency dental services only. Ninety percent of them notified the change of dental services online, and 69% of them offered free online professional consultations. The penetration rate of online technology was significantly higher in the eastern region than that of the central and western regions. CONCLUSIONS: There was a significant change in the health service provision of Chinese public tertiary dental hospitals during the COVID-19 epidemic and wider use of telehealth in the eastern region. CLINICAL RELEVANCE: This report demonstrated that dental health services were significantly affected by the COVID-19 epidemic in China, which might lead to a long-time impact on dental care in the future.

The impact of the COVID-19 epidemic on the utilization of emergency dental services.

BACKGROUND/PURPOSE: To assess how the current COVID-19 epidemic influenced peoples' utilization of emergency dental services in Beijing, China. METHODS: The first-visit patients seeking emergency dental services before or at the beginning of the COVID-19 epidemic were retrieved. Their demographic characteristics and the reasons for visiting were recorded and analyzed. RESULTS: There were 2,537 patients involved in this study. Thirty-eight percent fewer patients visited the dental urgency at the beginning of the COVID-19 epidemic than before. The distribution of dental problems has changed significantly. The proportion of dental and oral infection raised from 51.0% of pre-COVID-19 to 71.9% during COVID-19, and dental trauma decreased from 14.2% to 10.5%. Meanwhile, the non-urgency cases reduced to three-tenths of pre-COVID-19. CONCLUSION: Within the limitation of this study, the COVID-19 epidemic had a strong influence on the utilization of emergency dental services.