A Class of Sodium Transition-Metal Sulfide Cathodes with Anion Redox.

Sodium-ion batteries (SIBs) are entering commercial relevance as a sustainable and low-cost alternative to lithium-ion batteries. Improving the energy density of SIBs is critical to enable their widespread adoption. Here, we report a new class of cathode materials Na6MS4 (M = Co, Mn, Fe, and Zn) that exhibit high charge-storage capacity. Using Na6CoS4 as a prototypical example, we observe a six-electron conversion reaction dominated by anion redox, confirmed through various electrochemical and spectroscopic techniques. After the initial cycle, Na6CoS4 delivers a high capacity of 392 mA h g-1 with a long lifespan of over 500 cycles. The reaction involves initially the transformation of crystalline Na6CoS4 to a nearly amorphous structure consisting of mainly CoS and sulfur nanoparticles, which then reversibly cycles between nearly amorphous a-CoS/S and a-Na6CoS4. Such anion-redox-driven conversion-type cathodes hold the potential to enable energy-dense, stable SIBs. This article is protected by copyright. All rights reserved.

Association of physical activity pattern and risk of Parkinson's disease.

Increasing evidence suggests an association between exercise duration and Parkinson's disease. However, no high-quality prospective evidence exists confirming whether differences exist between the two modes of exercise, weekend warrior and equal distribution of exercise duration, and Parkinson's risk. Hence, this study aimed to explore the association between different exercise patterns and Parkinson's risk using exercise data from the UK Biobank. The study analyzed data from 89,400 UK Biobank participants without Parkinson's disease. Exercise data were collected using the Axivity AX3 wrist-worn triaxial accelerometer. Participants were categorized into three groups: inactive, regularly active, and engaged in the weekend warrior (WW) pattern. The relationship between these exercise patterns and Parkinson's risk was assessed using a multifactorial Cox model. During a mean follow-up of 12.32 years, 329 individuals developed Parkinson's disease. In a multifactorial Cox model, using the World Health Organization-recommended threshold of 150 min of moderate-to-vigorous physical activity per week, both the active WW group [hazard ratio (HR) = 0.58; 95% confidence interval (CI) = 0.43-0.78; P < 0.001] and the active regular group (HR = 0.44; 95% CI = 0.34-0.57; P < 0.001) exhibited a lower risk of developing Parkinson's disease compared with the inactive group. Further, no statistically significant difference was observed between the active WW and the active regular groups (HR = 0.77; 95% CI = 0.56-1.05; P = 0.099). In conclusion, in this cohort study, both the WW exercise pattern and an equal distribution of exercise hours were equally effective in reducing Parkinson's risk.

Bortezomib elevates intracellular free Fe2+ by enhancing NCOA4-mediated ferritinophagy and synergizes with RSL-3 to inhibit multiple myeloma cells.

Iron contributes to tumor initiation and progression; however, excessive intracellular free Fe2+ can be toxic to cancer cells. Our findings confirmed that multiple myeloma (MM) cells exhibited elevated intracellular iron levels and increased ferritin, a key protein for iron storage, compared with normal cells. Interestingly, Bortezomib (BTZ) was found to trigger ferritin degradation, increase free intracellular Fe2+, and promote ferroptosis in MM cells. Subsequent mechanistic investigation revealed that BTZ effectively increased NCOA4 levels by preventing proteasomal degradation in MM cells. When we knocked down NCOA4 or blocked autophagy using chloroquine, BTZ-induced ferritin degradation and the increase in intracellular free Fe2+ were significantly reduced in MM cells, confirming the role of BTZ in enhancing ferritinophagy. Furthermore, the combination of BTZ with RSL-3, a specific inhibitor of GPX4 and inducer of ferroptosis, synergistically promoted ferroptosis in MM cell lines and increased cell death in both MM cell lines and primary MM cells. The induction of ferroptosis inhibitor liproxstatin-1 successfully counteracted the synergistic effect of BTZ and RSL-3 in MM cells. Altogether, our findings reveal that BTZ elevates intracellular free Fe2+ by enhancing NCOA4-mediated ferritinophagy and synergizes with RSL-3 by increasing ferroptosisin MM cells.

Superstructure-Assisted Single-Atom Catalysis on Tungsten Carbides for Bifunctional Oxygen Reactions.

Single-atom catalysis (SAC) attracts wide interest for zinc-air batteries that require high-performance bifunctional electrocatalysts for oxygen reactions. However, catalyst design is still highly challenging because of the insufficient driving force for promoting multiple-electron transfer kinetics. Herein, we report a superstructure-assisted SAC on tungsten carbides for oxygen evolution and reduction reactions. In addition to the usual single atomic sites, strikingly, we reveal the presence of highly ordered Co superstructures in the interfacial region with tungsten carbides that induce internal strain and promote bifunctional catalysis. Theoretical calculations show that the combined effects from superstructures and single atoms strongly reduce the adsorption energy of intermediates and overpotential of both oxygen reactions. The catalyst therefore presented impressive bifunctional activity with an ultralow potential gap of 0.623 V and delivered a high power density of 188.5 mW cm-2 for assembled zinc-air batteries. This work opens up new opportunities for atomic catalysis.

hsa_circ_0008500 regulates Benzo(a)pyrene-loaded gypsum-induced inflammation and apoptosis in human bronchial epithelial cells via activation of Ahr/C-myc pathways.

Polycyclic aromatic hydrocarbons (PAHs) are major organic pollutants attached to fine particulate matter in the atmosphere. They induce lung inflammation, asthma, and other lung diseases. Exploring the toxic mechanism of PAHs on lung epithelial cells may provide a theoretical basis for the prevention and treatment of respiratory diseases induced by PAHs. In our study, 16 human bronchial epithelial (16HBE) cells were exposed to different concentrations of gypsum dust, Benzo(a)pyrene (BaP), and BaP-loaded gypsum dust for 24 hours. Gypsum dust loaded with BaP significantly increased the cytotoxicity of 16HBE cells, enhanced the production of lactate dehydrogenase (LDH), interleukin-6 (IL-6) and interleukin-8 (IL-8), induced cell apoptosis, and upregulate the expression of hsa_circ_0008500 (circ_0008500). The mechanism was studied with a BaP-loaded gypsum dust concentration of 1.25 mg/mL. StemRegenin 1 (SR1) pretreat significantly reduced the release of LDH, IL-6, and IL-8 and decreased the protein levels of Ahr、XAP2, C-myc, and p53. Second-generation sequencing indicated that circ_0008500 was highly expressed after 16HBE induced by BaP-loaded gypsum dust. Functional experiments confirmed that circ_0008500 promoted the inflammation and apoptosis of 16HBE cells induced by BaP-loaded gypsum dust by regulating the Ahr signaling pathway. Our study showed that fine particulate matter adsorption of BaP significantly increased the toxic effect of BaP on cells. By activating the Ahr/C-myc pathway, circ_0008500 promoted inflammation and apoptosis of 16HBE cells induced by BaP-loaded gypsum dust.

3D Flower-like Nanospheres Constructed by Transition Metal Telluride Nanosheets as Sulfur Immobilizers for High-Performance Room-Temperature Na-S Batteries.

Room-temperature sodium-sulfur (RT Na-S) batteries hold immense promise as next-generation energy storage systems, owing to their exceptionally high theoretical capacity, abundant resources, eco-friendliness, and affordability. Nevertheless, their practical application is impeded by the shuttling effect of sodium polysulfides (NaPSs) and sluggish sulfur redox kinetics. In this study, an advanced strategy by designing 3D flower-like molybdenum telluride (MoTe2) as an efficient catalyst to promote sulfur redox for RT Na-S batteries is presented. The unique 3D flower-like MoTe2 effectively prevents NaPS shuttling and simultaneously offers abundant active catalytic sites facilitating polysulfide redox. Consequently, the obtained MoTe2/S cathode delivers an outstanding initial reversible capacity of 1015 mAh g-1 at 0.1 C, along with robust cycling stability of retaining 498 mAh g-1 at 1 C after 500 cycles. In addition, pouch cells are fabricated with the MoTe2 additive to deliver an ultrahigh initial discharge capacity of 890 mAh g-1 and remain stable over 40 cycles under practically necessary conditions, demonstrating the potential application in the commercialization of RT Na-S batteries.

Diallyl disulfide synergizes with melphalan to increase apoptosis and DNA damage through elevation of reactive oxygen species in multiple myeloma cells.

Diallyl disulfide (DADS), one of the main components of garlic, is well known to have anticancer effects on multiple cancers. However, its efficacy in treating multiple myeloma (MM) is yet to be determined. We explored the effects of DADS on MM cells and investigated the synergistic effects of DADS when combined with five anti-MM drugs, including melphalan, bortezomib, carfilzomib, doxorubicin, and lenalidomide. We analyzed cell viability, cell apoptosis, and DNA damage to determine the efficacy of DADS and the drug combinations. Our findings revealed that DADS induces apoptosis in MM cells through the mitochondria-dependent pathway and increases the levels of γ-H2AX, a DNA damage marker. Combination index (CI) measurements indicated that the combination of DADS with melphalan has a significant synergistic effect on MM cells. This was further confirmed by the increases in apoptotic cells and DNA damage in MM cells treated with the two drug combinations compared with those cells treated with a single drug alone. The synergy between DADS and melphalan was also observed in primary MM cells. Furthermore, mechanistic investigations showed that DADS decreases reduced glutathione (GSH) levels and increases reactive oxygen species (ROS) production in MM cells. The addition of GSH is effective in neutralizing DADS cytotoxicity and inhibiting the synergy between DADS and melphalan in MM cells. Taken together, our study highlights the effectiveness of DADS in treating MM cells and the promising therapeutic potential of combining DADS and melphalan for MM treatment.

Intercalation-type catalyst for non-aqueous room temperature sodium-sulfur batteries.

Ambient-temperature sodium-sulfur (Na-S) batteries are potential attractive alternatives to lithium-ion batteries owing to their high theoretical specific energy of 1,274 Wh kg-1 based on the mass of Na2S and abundant sulfur resources. However, their practical viability is impeded by sodium polysulfide shuttling. Here, we report an intercalation-conversion hybrid positive electrode material by coupling the intercalation-type catalyst, MoTe2, with the conversion-type active material, sulfur. In addition, MoTe2 nanosheets vertically grown on graphene flakes offer abundant active catalytic sites, further boosting the catalytic activity for sulfur redox. When used as a composite positive electrode and assembled in a coin cell with excess Na, a discharge capacity of 1,081 mA h gs-1 based on the mass of S with a capacity fade rate of 0.05% per cycle over 350 cycles at 0.1 C rate in a voltage range of 0.8 to 2.8 V is realized under a high sulfur loading of 3.5 mg cm-2 and a lean electrolyte condition with an electrolyte-to-sulfur ratio of 7 µL mg-1. A fundamental understanding of the electrocatalysis of MoTe2 is further revealed by in-situ synchrotron-based operando X-ray diffraction and ex-situ time-of-flight secondary ion mass spectrometry.

Evaluation of total tumor volume reduction ratio in initially unresectable colorectal liver metastases after first-line systemic treatment.

PURPOSE: Total tumor volume (TTV) may play an essential role in the estimation of tumor burden. This study is aimed to investigate the clinical value of the reduction ratio of TTV as a valuable indicator of clinical outcomes in patients with colorectal liver metastases (CRLM). METHODS: A total of 240 initially unresectable CRLM patients who underwent first-line systemic treatment were enrolled in this study. TTV at baseline and at the end of first-line treatment were assessed using a three-dimensional reconstruction system according to CT or MRI images. Survival was evaluated using Kaplan-Meier analysis and compared using Cox proportional hazard ratios (HR). RESULTS: A total of 212 (88.3%) patients achieved tumor regression with a median reduction ratio of TTV of 86.0%. An increasing reduction ratio of TTV was associated with a gradually ascending successful conversion outcome. Patients with a reduction ratio >86.0% had better survival than those with a reduction ratio 0-86.0% or <0 (5-year overall survival (OS) rates, 64.4% vs. 44.9% vs. 23.5%, P < 0.001; 5-year progression-free survival (PFS) rates, 36.3% vs. 28.2% vs. 6.5%, P < 0.001). Multivariate analysis indicated that the reduction ratio of TTV ≤ 86.0% (OR [95%CI]: 4.956 [2.654-9.253], P < 0.001) was an independent factor for conversion failure outcome. Cox analyses revealed that the reduction ratio of TTV ≤ 86.0% was an independent factor for both unfavorable OS (HR [95%CI]: 2.216 [1.332-3.688], P = 0.002) and PFS (HR [95%CI]: 2.023 [1.376-2.974], P < 0.001). CONCLUSIONS: The reduction ratio of TTV was an effective indicator for conversion outcome and long-term prognosis in patients with initially unresectable CRLM after first-line systemic treatment.

Clinical characteristics of hypersensitivity pneumonitis: non-fibrotic and fibrotic subtypes.

BACKGROUND: The presence of fibrosis is a criterion for subtype classification in the newly updated hypersensitivity pneumonitis (HP) guidelines. The present study aimed to summarize differences in clinical characteristics and prognosis of non-fibrotic hypersensitivity pneumonitis (NFHP) and fibrotic hypersensitivity pneumonitis (FHP) and explore factors associated with the presence of fibrosis. METHODS: In this prospective cohort study, patients diagnosed with HP through a multidisciplinary discussion were enrolled. Collected data included demographic and clinical characteristics, laboratory findings, and radiologic and histopathological features. Logistic regression analyses were performed to explore factors related to the presence of fibrosis. RESULTS: A total of 202 patients with HP were enrolled, including 87 (43.1%) NFHP patients and 115 (56.9%) FHP patients. Patients with FHP were older and more frequently presented with dyspnea, crackles, and digital clubbing than patients with NFHP. Serum levels of carcinoembryonic antigen, carbohydrate antigen 125, carbohydrate antigen 153, gastrin-releasing peptide precursor, squamous cell carcinoma antigen, and antigen cytokeratin 21-1, and count of bronchoalveolar lavage (BAL) eosinophils were higher in the FHP group than in the NFHP group. BAL lymphocytosis was present in both groups, but less pronounced in the FHP group. Multivariable regression analyses revealed that older age, <20% of lymphocyte in BAL, and ≥1.75% of eosinophil in BAL were risk factors for the development of FHP. Twelve patients developed adverse outcomes, with a median survival time of 12.5 months, all of whom had FHP. CONCLUSIONS: Older age, <20% of lymphocyte in BAL, and ≥1.75% of eosinophil in BAL were risk factors associated with the development of FHP. Prognosis of patients with NFHP was better than that of patients with FHP. These results may provide insights into the mechanisms of fibrosis in HP.

Heterostructures Regulating Lithium Polysulfides for Advanced Lithium-Sulfur Batteries.

Sluggish reaction kinetics and severe shuttling effect of lithium polysulfides seriously hinder the development of lithium-sulfur batteries. Heterostructures, due to unique properties, have congenital advantages that are difficult to be achieved by single-component materials in regulating lithium polysulfides by efficient catalysis and strong adsorption to solve the problems of poor reaction kinetics and serious shuttling effect of lithium-sulfur batteries. In this review, the principles of heterostructures expediting lithium polysulfides conversion and anchoring lithium polysulfides are detailedly analyzed, and the application of heterostructures as sulfur host, interlayer, and separator modifier to improve the performance of lithium-sulfur batteries is systematically reviewed. Finally, the problems that need to be solved in the future study and application of heterostructures in lithium-sulfur batteries are prospected. This review will provide a valuable reference for the development of heterostructures in advanced lithium-sulfur batteries.

Freestanding ReS2/Graphene Heterostructures as Binder-Free Anodes for Lithium-Ion Batteries.

It is still challenging to develop anode materials with high capacity and long cycling stability for lithium-ion batteries (LIBs). To address such issues, herein, for the first time, we present a three-dimensional and freestanding ReS2/graphene heterostructure (3DRG) as an anode synthesized via a one-pot hydrothermal method. The hybrid shows a hierarchically sandwich-like, nanoporous, and conductive three-dimensional (3D) network constructed by two-dimensional (2D) ReS2/graphene heterostructural nanosheets, which can be directly utilized as a freestanding and binder-free anode for LIBs. When the current density is 100 mA g-1, the 3DRG anode delivers a high reversible specific capacity of 653 mAh g-1. The 3DRG anode also delivers higher rate capability and cycling stability than the bare ReS2 anode. The markedly boosted electrochemical properties derive from the unique nanoarchitecture, which guarantees massive electrochemical active sites, short channels of lithium-ion diffusion, fast electron/ion transportation, and inhibition of the volume change of ReS2 for LIBs.

Vaccination options for pregnant women during the Omicron period.

Omicron exhibits reduced pathogenicity in general population than the previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. However, the severity of disease and pregnancy outcomes of Omicron infection among pregnant women have not yet been definitively established. Meanwhile, substantial proportions of this population have doubts about the necessity of vaccination given the reports of declining efficacy of coronavirus disease 2019 (COVID-19) vaccines. Herein, we comprehensively discuss the clinical outcomes of infected pregnant women during the Omicron period and summarize the available data on the safety and efficacy profile of COVID-19 vaccination. The results found that the incidence of moderate and severe disease, maternal mortality, pregnancy loss, preterm delivery, stillbirth, preeclampsia/eclampsia, and gestational hypertension during the Omicron period are similar to those during the Pre-Delta period. In view of the effects of mass vaccination and previous natural infection on disease severity, the virulence of Omicron in pregnant women may be comparable to or even higher than that of the Pre-Delta variant. Moreover, the currently approved COVID-19 vaccines are safe and effective for pregnant women. Particularly, those who received a second or third dose had significantly less severe disease with little progression to critical illness or death compared with those who were unvaccinated or received only one dose. Therefore, in the case of the rapid spread of Omicron, pregnant women should still strictly follow preventive measures to avoid infection and receive the COVID-19 vaccine in a timely manner.

External validation of the GAP model in Chinese patients with idiopathic pulmonary fibrosis.

INTRODUCTION: The GAP model was widely used as a simple risk "screening" method for patients with idiopathic pulmonary fibrosis (IPF). OBJECTIVES: We sought to validate the GAP model in Chinese patients with IPF to evaluate whether it can accurately predict the risk for mortality. METHODS: A total of 212 patients with IPF diagnosed at China-Japan Friendship Hospital from 2015 to 2019 were enrolled. The latest follow-up ended in September 2022. Cumulative mortality of each GAP stage was calculated and compared based on Fine-Gray models for survival, and lung transplantation was treated as a competing risk. The performance of the model was evaluated in terms of both discrimination and calibration. RESULTS: The cumulative mortality in patients with GAP stage III was significantly higher than that in those with GAP stage I or II (Gray's test p < 0.0001). The Harrell c-index for the GAP calculator was 0.736 (95% CI: 0.667-0.864). The discrimination for the GAP staging system were similar with that for the GAP calculator. The GAP model overestimated the mortality rate at 1- and 2-year in patients classified as GAP stage I (6.90% vs. 1.77% for 1-year, 14.20% vs. 6.78% for 2-year). CONCLUSIONS: Our findings indicated that the GAP model overestimated the mortality rate in mild group.

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

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.

USP13 Deficiency Impairs Autophagy and Facilitates Age-related Lung Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is an age-related disease. Failure of the proteostasis network with age, including insufficient autophagy, contributes to the pathology of IPF. Mechanisms underlying autophagy disruption in IPF are unclear and may involve regulation of USP (ubiquitin-specific protease) by post-translational modifications. To expand our previous observation of low USP13 expression in IPF, this study evaluated the role of USP13 in age-related lung fibrosis. Here, we demonstrated that Usp13-deficient aged mice exhibited impaired autophagic activity and increased vulnerability to bleomycin-induced fibrosis. Mechanistically, USP13 interacted with and deubiquitinated Beclin 1, and Beclin 1 overexpression abolished the effects of USP13 disruption. In addition, Beclin 1 inhibition resulted in insufficient autophagy and more severe lung fibrosis after bleomycin injury, consistent with the phenotype of aged Usp13-deficient mice. Collectively, we show a protective role of USP13 in age-related pulmonary fibrosis. Aging-mediated USP13 loss impairs autophagic activity and facilitates lung fibrosis through Beclin 1 deubiquitination. Our findings support the notion that age-dependent dysregulation of autophagic regulators enhances vulnerability to lung fibrosis.

Highly Efficient Organosulfur and Lithium-Metal Hosts Enabled by C@Fe3 N Sponge.

Lithium-organosulfur (Li-OS) batteries, despite possessing high theoretical specific capacity, encounter a few practical challenges, including unsatisfactory lifespan and low active material utilization under realistic conditions. Here, diisoropyl xanthogen polysulfide (DIXPS) has been selected as a model organosulfur compound to investigate the practical feasibility of Li-OS batteries under realistic conditions. A well-designed freestanding carbon sponge decorated with Fe3 N nanoparticles (C@Fe3 N) is introduced into the Li-OS cells as a scaffold for both Li and DIXPS. The lithiophilic property of the C@Fe3 N host guides uniform lithium deposition at the anode, and the catalysis of the DIXPS conversion reaction promotes the kinetics at the cathode. Impressively, the synergistic effect of C@Fe3 N leads to an extremely stable cycling performance over 1 000 cycles in a Li-OS full cell under realistic conditions.

Blood monocyte counts as a prognostic biomarker and predictor in Chinese patients with idiopathic pulmonary fibrosis.

Objectives: We sought to evaluate the prognostic value of blood routine parameters and biochemical parameters, especially inflammation-related biomarkers, and establish an inflammation-related prognostic model in Chinese patients with idiopathic pulmonary fibrosis (IPF). Material/methods: Patients diagnosed as IPF at Beijing Chaoyang Hospital and aged 40 years and older were consecutively enrolled from June 2000 to March 2015, and finally, a total of 377 patients were enrolled in the derivation cohort. The follow-up ended in December 2016. We used Cox proportional hazard model to calculate the hazard ratio (HR) and establish the prognostic model. The discrimination and calibration of the prognostic model were evaluated in an independent validation cohort enrolled from China-Japan Friendship Hospital between January 2015 and December 2019. Results: Multivariate analysis revealed that patients with elevated monocyte-to-red blood cell count ratio (MRR) and monocyte counts showed increased risk of mortality. The clinical-physiological-biomarker (CPB) index and CPB stage we established in this study were a significant predictor, and the C-index for CPB index and CPB stage in the validation cohort was 0.635 (95% CI: 0.558-0.712) and 0.619 (95% CI: 0.544-0.694), respectively. Patients in CPB stage III had the poorest survival. Conclusion: We developed and validated a new inflammation-related prognostic model (CPB index and CPB stage) which was integration of age, gender, FVC (%, predicted), DLCO (%, predicted), Charlson Comorbidity Index, and blood monocyte counts. This prediction model exhibited strong ability in predicting mortality in Chinese patients with IPF.

The importance of booster vaccination in the context of Omicron wave.

Omicron (B.1.1.529) was first detected in a sample collected in Botswana on November 11, 2021, and has rapidly replaced Delta as the dominant global variant given the robust transmissibility. Moreover, it displays a lower virulence than other variants. However, the pathogenicity of Omicron appears to be underestimated in view of the increasing levels of herd immunity through natural infection or vaccination. Additionally, the volume of hospitalizations and deaths increase in proportion to the number of cases due to the high transmissibility of Omicron. Therefore, vaccination remains an important public health priority. Notably, a series of important mutations in the Omicron spike protein, especially in the receptor-binding domain and N-terminal domain, appears to be associated with immune escape capacity, reducing the willingness of people to receive vaccines. Herein, we provide an in-depth discussion to assess the effectiveness of the second and third vaccination against Omicron variant. On the one hand, the two-dose vaccination program adopted by many countries is insufficient to prevent Omicron infection given the mutations correlated with immune escape and the decline in vaccine efficacy over time. On the other hand, booster dose significantly increases the protective efficacy against Omicron infection. Most importantly, heterologous third dose vaccination induces a more robust immune response than homologous booster dose. Therefore, under the special background of this pandemic, there is an urgent need to accelerate the third dose of vaccination, especially providing better booster vaccination strategies, to combat emerging Omicron variant.