Screening Hesitancy of a Universal Voluntary-based Rapid Antigen Test for coronavirus disease 2019 (COVID-19) During Omicron Wave in Hong Kong.

BACKGROUND: The Hong Kong government distributed rapid antigen test (RAT) kits to households across the city and called for a universal voluntary testing exercise for three consecutive days during the Omicron wave to identify infected persons early for quarantine and disrupt transmission chains in the community. We conducted a survey to evaluate the participation rates and explore the determinants of voluntary RAT adoption and hesitancy. METHODS: This cross-sectional survey was conducted through computer-assisted telephone interviews from 19 May to 16 June 2022 using an overlapping dual-frame telephone number sampling design. Information on willingness to adopt voluntary RAT, four themes of personal qualities, attitudes toward the government's health policies, incentives to motivate RAT adoption, and personal sociodemographic factors were collected. Logistic regression analysis was used to examine the factors associated with RAT adoption. RESULTS: Of the 1010 participants, 490 successfully responded to the fixed-line and 520 to the mobile phone survey, with response rates of 1.42% and 1.63% and screen hesitancy rates of 36.1% and 39.3%, respectively. Participants of adoption RAT were those aged 30-49 years, with high perceived COVID-19 infection severity, ≥ 3 doses of COVID-19 vaccination, and more agreement with the health policies on material resources and quarantine orders. Individuals who were less risk seeking and more altruistic reported a higher adoption of voluntary RAT. CONCLUSIONS: Understanding the willingness to participate in a voluntary universal testing programme might shed light on effective ways to minimise screening hesitancy in future public health strategies and campaigns.

Association of Vaccine Pass Policy and Omicron Incidence with COVID vaccine uptakes in Hong Kong.

We observed the association of vaccine coverage with the implementation of the Vaccine Pass policy and the intensity of the Omicron pandemic. Vaccine policy and transparent information dissemination are indispensable interventions promoting vaccination uptake.

Comparison of Resilience Among Healthcare Workers During the COVID-19 Pandemics: A Multinational Cross-Sectional Survey in Southeast Asian Jurisdictions.

Objectives: To examine the level of resilience among the frontline healthcare workers (HCWs) in four different Southeast Asian jurisdictions and identify the potential factors that may enhance healthcare workers resilience. Methods: An online cross-sectional survey was carried out among 3,048 eligible healthcare workers in Hong Kong, Nepal, Vietnam, and Taiwan from May 2021 to July 2022, and information on individual resilience, socio-demographic characteristics, organizational supports, and personal exposures were collected. A binary logistic regression model was used to identify the factors that were associated with a high resilience level. Results: The resilience score was the highest among healthcare workers of Vietnam, followed by Taiwan and Hong Kong, with Nepal scoring the lowest. Participants with old age, part-time work, higher education level, more satisfaction with workplace policy, better organizational supports, and fewer COVID-specific worries were associated with higher resilience. Healthcare workers who were satisfied with the overall organizational policy support had an OR of 1.48 (95% CI: 1.25-1.76) for a high resilience level. Conclusion: Implementing satisfying organizational policies and establishing supportive work environments for frontline healthcare workers can increase individual resilience and organizational stability.

Associations between Health Literacy, Trust, and COVID-19 Vaccine Hesitancy: The Case of Hong Kong.

This study investigates how health literacy (HL) and trust in health information affected COVID-19 vaccine hesitancy among Chinese Hong Kong adults. A cross-sectional study was conducted in August 2022. A total of 401 participants completed the study. Participants completed a newly developed Hong Kong HL scale and self-reported their trust levels in health information from different resources. The proportions of early uptake of the first dose and booster dose of COVID-19 vaccine were 69.1% and 71.8%, respectively. The risk of delaying the first dose was higher among participants with inadequate functional HL (OR = 0.58, p = 0.015), adequate levels of two subdomains of critical HL (OR = 1.82, p = 0.013; OR = 1.91, p < 0.01), and low-level trust in health information from the government (OR = 0.57, p = 0.019). Respondents with adequate interactive HL (OR = 0.52, p = 0.014) and inadequate level of one subdomain of critical HL (OR =1.71, p = 0.039) were more likely to delay the booster dose. This negative association between critical HL and vaccination was suppressed by trust in health information from the government. This study shows that HL and trust in health information from the government are associated with COVID-19 vaccine hesitancy. Efforts should be directed at providing tailored communication strategies with regard to people's HL and increasing public confidence in health authorities to decrease vaccine hesitancy.

Comparison of Resilience Among Healthcare Workers During the COVID-19 Pandemics: A Multinational Cross-Sectional Survey in Southeast Asian Jurisdictions

Objectives: To examine the level of resilience among the frontline healthcare workers (HCWs) in four different Southeast Asian jurisdictions and identify the potential factors that may enhance healthcare workers resilience. Methods: An online cross-sectional survey was carried out among 3,048 eligible healthcare workers in Hong Kong, Nepal, Vietnam, and Taiwan from May 2021 to July 2022, and information on individual resilience, socio-demographic characteristics, organizational supports, and personal exposures were collected. A binary logistic regression model was used to identify the factors that were associated with a high resilience level. Results: The resilience score was the highest among healthcare workers of Vietnam, followed by Taiwan and Hong Kong, with Nepal scoring the lowest. Participants with old age, part-time work, higher education level, more satisfaction with workplace policy, better organizational supports, and fewer COVID-specific worries were associated with higher resilience. Healthcare workers who were satisfied with the overall organizational policy support had an OR of 1.48 (95% CI: 1.25–1.76) for a high resilience level. Conclusion: Implementing satisfying organizational policies and establishing supportive work environments for frontline healthcare workers can increase individual resilience and organizational stability.

Nab-paclitaxel plus S-1 versus oxaliplatin plus S-1 as first-line treatment in advanced gastric cancer: results of a multicenter, randomized, phase III trial (GAPSO study).

Background: This study aimed to investigate the superiority of nab-paclitaxel plus S-1 (AS) over oxaliplatin plus S-1 (SOX) in patients with advanced gastric cancer (AGC). Methods: In this multicenter, randomized, phase III superiority trial, eligible patients with unresectable, locally advanced gastric adenocarcinoma were recruited and randomly assigned (1:1) to receive AS (nab-paclitaxel 260 mg/m2 on day 1 or 130 mg/m2 on days 1 and 8; oral S-1 40-60 mg twice daily for 14 days) or SOX (130 mg/m2 oxaliplatin on day 1; oral S-1 40-60 mg twice daily for 14 days) every 3 weeks for up to six cycles. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were overall survival, objective response rate, and safety. Results: Owing to slow enrolment, an unplanned interim analysis was performed, resulting in the early termination of the study on 31 December 2021 (data cutoff). Between March 2019 and March 2021, 97 patients (AS, n = 48; SOX, n = 49) were treated and evaluated for efficacy and safety of AS and SOX. As of the data cutoff, the median follow-up was 23.13 months [95% confidence interval (CI), 13.39-32.87]. The median PFS was 9.03 months (95% CI, 6.50-11.56) in the AS group and 5.07 months (95% CI, 4.33-5.81) in the SOX group, demonstrating a better PFS tendency following AS treatment than SOX treatment (hazard ratio = 0.59; 95% CI, 0.37-0.94; p = 0.03). The most common grade 3 or worse adverse events were anemia, neutropenia, and leukopenia in both groups, with a higher incidence of thrombocytopenia in the SOX group. Conclusion: Although this study was terminated early, the results demonstrated a better PFS tendency in patients with AGC who were treated with AS than in those treated with SOX, with controllable toxicities. Trial registration: Clinical Trials.gov identifiers: NCT03801668. Registered January 11, 2019.

COVID-19 Vaccine Willingness and Related Factors Among Health Care Workers in 3 Southeast Asian Jurisdictions.

Importance: COVID-19 vaccine hesitancy is widespread and may lead to refusal or delay of vaccination, eventually reducing the overall vaccination coverage rate and vaccine effectiveness. Willingness to receive COVID-19 vaccination among health care workers (HCWs) is diverse across different jurisdictions. Objective: To assess the COVID-19 vaccine willingness among HCWs in 3 Southeast Asian jurisdictions in the context of pandemic severity and vaccination policy. Design, Setting, and Participants: A cross-sectional online survey was conducted among frontline HCWs in Hong Kong, Nepal, and Vietnam from May to November 2021. Eligible participants were nurses and doctors aged 18 and older, working in public or private health care settings on a full-time or part-time basis. Exposures: The COVID-19 pandemic and vaccination policy. Main Outcomes and Measures: COVID-19 vaccination willingness was defined as HCW willingness toward receiving the COVID-19 vaccine in full course or the first dose of the vaccine, and willingness to take the second dose. Information on sociodemographic characteristics, the history of seasonal influenza vaccination, attitudes toward vaccination, and opinions on strategies associated with vaccination uptake from the study participants. Results: Among the 3396 eligible doctors and nurses who participated in the survey, 2834 (83.4%) were from Hong Kong, 328 (9.7%) were from Nepal, and 234 (6.9%) were from Vietnam. Most respondents were female (76.2% [2589 ]), aged 30 to 39 years (31.2% [1058]), and nurse HCWs (77.6% [2636]); the response rates were 11% (2834 of 25 000) in Hong Kong, 36% (328 of 900) in Nepal, and 13% (234 of 1800) in Vietnam. Overall, the prevalence rate of willingness to take the COVID-19 vaccine was highest in Nepal (95.4% [313 of 328]), followed by Vietnam (90.6% [212 of 234]), and lowest in Hong Kong (54.4% [1542 of 2834]), relating to their different attitudes and opinions toward the COVID-19 vaccination, and the pandemic severity and vaccination policy in the 3 jurisdictions. Doctors were more willing to take COVID-19 vaccination than nurses (odds ratio, 5.28; 95% CI, 3.96-7.04). Older age (odds ratios, 1.39-3.70), male gender (odds ratio, 1.41; 95% CI, 1.11-1.75), higher educational level (odds ratio, 1.48; 95% CI, 1.17-1.87), and having seasonal influenza vaccination uptake history (odds ratio, 2.15; 95% CI, 1.82-2.54) were found to be associated with increased willingness. Choice of vaccination brand with adequate information, immunity passport, time off from work for vaccination and subsidy for travel to inconvenient vaccination centers were considered as strategies to enhance vaccine willingness. Conclusions and Relevance: In this survey study, vaccination unwillingness existed among HCWs in Southeast Asian regions, especially in Hong Kong. The findings of this study may have utility in the formulation of vaccination promotion strategies such as vaccination incentives. Attitudes toward vaccination in HCWs might be examples for the general population; however, changes over time should be further investigated.

Rational development of a combined mRNA vaccine against COVID-19 and influenza.

As the world continues to experience the COVID-19 pandemic, seasonal influenza remain a cause of severe morbidity and mortality globally. Worse yet, coinfection with SARS-CoV-2 and influenza A virus (IAV) leads to more severe clinical outcomes. The development of a combined vaccine against both COVID-19 and influenza is thus of high priority. Based on our established lipid nanoparticle (LNP)-encapsulated mRNA vaccine platform, we developed and characterized a novel mRNA vaccine encoding the HA antigen of influenza A (H1N1) virus, termed ARIAV. Then, ARIAV was combined with our COVID-19 mRNA vaccine ARCoV, which encodes the receptor-binding domain (RBD) of the SARS-CoV-2 S protein, to formulate the final combined vaccine, AR-CoV/IAV. Further characterization demonstrated that immunization with two doses of AR-CoV/IAV elicited robust protective antibodies as well as antigen-specific cellular immune responses against SARS-CoV-2 and IAV. More importantly, AR-CoV/IAV immunization protected mice from coinfection with IAV and the SARS-CoV-2 Alpha and Delta variants. Our results highlight the potential of the LNP-mRNA vaccine platform in preventing COVID-19 and influenza, as well as other respiratory diseases.

Self-Adjuvanting Lipoprotein Conjugate αGalCer-RBD Induces Potent Immunity against SARS-CoV-2 and its Variants of Concern.

Safe and effective vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants are the best approach to successfully combat the COVID-19 pandemic. The receptor-binding domain (RBD) of the viral spike protein is a major target to develop candidate vaccines. α-Galactosylceramide (αGalCer), a potent invariant natural killer T cell (iNKT) agonist, was site-specifically conjugated to the N-terminus of the RBD to form an adjuvant-protein conjugate, which was anchored on the liposome surface. This is the first time that an iNKT cell agonist was conjugated to the protein antigen. Compared to the unconjugated RBD/αGalCer mixture, the αGalCer-RBD conjugate induced significantly stronger humoral and cellular responses. The conjugate vaccine also showed effective cross-neutralization to all variants of concern (B.1.1.7/alpha, B.1.351/beta, P.1/gamma, B.1.617.2/delta, and B.1.1.529/omicron). These results suggest that the self-adjuvanting αGalCer-RBD has great potential to be an effective COVID-19 vaccine candidate, and this strategy might be useful for designing various subunit vaccines.

Safety of inactivated COVID-19 vaccine in tuberous sclerosis complex patients with epilepsy treated with rapamycin.

PURPOSE: To assess the safety of inactivated coronavirus 2019 disease (COVID-19) vaccine in tuberous sclerosis complex (TSC) patients with epilepsy. METHODS: All patients with epilepsy were selected from Efficacy and Safety of Sirolimus in Pediatric Patients with Tuberous Sclerosis (ESOSPIT) project and younger than 17 years old. The patients were treated with mTOR inhibitors (rapamycin). A total of 44 patients who completed the two-dose inactivated COVID-19 vaccine between July 7, 2021, and January 1, 2022, were enrolled. RESULTS: The median age of seizure onset was 23 months. About two-thirds of patients have focal seizures. Thirty-three patients use antiseizure medications. The mean duration of rapamycin treatment was 55.59 ± 18.42 months. Adverse reactions within 28 days after injection occurred in 11 patients (25%), all were under 12 years old. Injection site pain was the most reported event (20.45%), which was mild in severity and improved within one day. All patients had no seizure-related changes after vaccination. CONCLUSION: This study shows that the inactivated COVID-19 vaccine was well tolerated and safe in TSC patients with epilepsy, as well as for those treated with mTOR inhibitors.

A highly immunogenic live-attenuated vaccine candidate prevents SARS-CoV-2 infection and transmission in hamsters.

The highly pathogenic and readily transmissible SARS-CoV-2 has caused a global coronavirus pandemic, urgently requiring effective countermeasures against its rapid expansion. All available vaccine platforms are being used to generate safe and effective COVID-19 vaccines. Here, we generated a live-attenuated candidate vaccine strain by serial passaging of a SARS-CoV-2 clinical isolate in Vero cells. Deep sequencing revealed the dynamic adaptation of SARS-CoV-2 in Vero cells, resulting in a stable clone with a deletion of seven amino acids (N679SPRRAR685) at the S1/S2 junction of the S protein (named VAS5). VAS5 showed significant attenuation of replication in multiple human cell lines, human airway epithelium organoids, and hACE2 mice. Viral fitness competition assays demonstrated that VAS5 showed specific tropism to Vero cells but decreased fitness in human cells compared with the parental virus. More importantly, a single intranasal injection of VAS5 elicited a high level of neutralizing antibodies and prevented SARS-CoV-2 infection in mice as well as close-contact transmission in golden Syrian hamsters. Structural and biochemical analysis revealed a stable and locked prefusion conformation of the S trimer of VAS5, which most resembles SARS-CoV-2-3Q-2P, an advanced vaccine immunogen (NVAX-CoV2373). Further systematic antigenic profiling and immunogenicity validation confirmed that the VAS5 S trimer presents an enhanced antigenic mimic of the wild-type S trimer. Our results not only provide a potent live-attenuated vaccine candidate against COVID-19 but also clarify the molecular and structural basis for the highly attenuated and super immunogenic phenotype of VAS5.

Lipid nanoparticle-encapsulated mRNA antibody provides long-term protection against SARS-CoV-2 in mice and hamsters.

Monoclonal antibodies represent important weapons in our arsenal to against the COVID-19 pandemic. However, this potential is severely limited by the time-consuming process of developing effective antibodies and the relative high cost of manufacturing. Herein, we present a rapid and cost-effective lipid nanoparticle (LNP) encapsulated-mRNA platform for in vivo delivery of SARS-CoV-2 neutralization antibodies. Two mRNAs encoding the light and heavy chains of a potent SARS-CoV-2 neutralizing antibody HB27, which is currently being evaluated in clinical trials, were encapsulated into clinical grade LNP formulations (named as mRNA-HB27-LNP). In vivo characterization demonstrated that intravenous administration of mRNA-HB27-LNP in mice resulted in a longer circulating half-life compared with the original HB27 antibody in protein format. More importantly, a single prophylactic administration of mRNA-HB27-LNP provided protection against SARS-CoV-2 challenge in mice at 1, 7 and even 63 days post administration. In a close contact transmission model, prophylactic administration of mRNA-HB27-LNP prevented SARS-CoV-2 infection between hamsters in a dose-dependent manner. Overall, our results demonstrate a superior long-term protection against SARS-CoV-2 conferred by a single administration of this unique mRNA antibody, highlighting the potential of this universal platform for antibody-based disease prevention and therapy against COVID-19 as well as a variety of other infectious diseases.

Does flattening the curve make a difference? An investigation of the COVID-19 pandemic based on an SIR model

We use a susceptible-infective-removed (SIR) model to examine the impacts of different isolation measures to combat the COVID-19 pandemic. The model predicts that strong isolation measures in the early stage of the pandemic can not only delay the time for the number of infections and deaths to reach the peak but also greatly reduce the cumulative number of infections and deaths. We verify the model predictions by using the simulation and the data of the COVID-19 cases. The results are independent of the joint distribution of the fatality rate and the initial number of active cases.

Inhaled heparin polysaccharide nanodecoy against SARS-CoV-2 and variants.

The heparin polysaccharide nanoparticles block the interaction between heparan sulfate/S protein and inhibit the infection of both wild-type SARS-CoV-2 pseudovirus and the mutated strains through pulmonary delivery.Image 1.

RBD conjugate vaccine with a built-in TLR1/2 agonist is highly immunogenic against SARS-CoV-2 and variants of concern.

The coronavirus 2019 (COVID-19) pandemic is causing serious impacts in the world, and safe and effective vaccines and medicines are the best methods to combat the disease. The receptor-binding domain (RBD) of the SARS-CoV-2 spike protein plays a key role in interacting with the angiotensin-converting enzyme 2 (ACE2) receptor, and is regarded as an important target of vaccines. Herein, we constructed the adjuvant-protein conjugate Pam3CSK4-RBD as a vaccine candidate, in which the N-terminal of the RBD was site-selectively oxidized by transamination and conjugated with the TLR1/2 agonist Pam3CSK4. This demonstrated that the conjugation of Pam3CSK4 significantly enhanced the anti-RBD antibody response and cellular response. In addition, sera from the Pam3CSK4-RBD immunized group efficiently inhibited the binding of the RBD to ACE2 and protected cells from SARS-CoV-2 and four variants of concern (alpha, beta, gamma and delta), indicating that this adjuvant strategy could be one of the effective means for protein vaccine development.

Structural characteristics of Heparan sulfate required for the binding with the virus processing Enzyme Furin.

Furin is one of the nine-member proprotein convertase family. Furin cleaves proteins with polybasic residues, which includes many viral glycoproteins such as SARS-Cov-2 spike protein. The cleavage is required for the activation of the proteins. Currently, the mechanisms that regulate Furin activity remain largely unknown. Here we demonstrated that Furin is a novel heparin/heparan sulfate binding protein by the use of biochemical and genetic assays. The KD is 9.78 nM based on the biolayer interferometry assay. Moreover, we found that sulfation degree, site-specific sulfation (N-sulfation and 3-O-sulfation), and iduronic acid are the major structural determinants for the binding. Furthermore, we found that heparin inhibits the enzymatic activity of Furin when pre-mixes heparin with either Furin or Furin substrate. We also found that the Furin binds with cells of different origin and the binding with the cells of lung origin is the strongest one. These data could advance our understanding of the working mechanism of Furin and will benefit the Furin based drug discovery such as inhibitors targeting the interaction between heparan sulfate and Furin for inhibition of viral infection.

Neutralization of SARS-CoV-2 pseudovirus using ACE2-engineered extracellular vesicles.

The spread of coronavirus disease 2019 (COVID-19) throughout the world has resulted in stressful healthcare burdens and global health crises. Developing an effective measure to protect people from infection is an urgent need. The blockage of interaction between angiotensin-converting enzyme 2 (ACE2) and S protein is considered an essential target for anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) drugs. A full-length ACE2 protein could be a potential drug to block early entry of SARS-CoV-2 into host cells. In this study, a therapeutic strategy was developed by using extracellular vesicles (EVs) with decoy receptor ACE2 for neutralization of SARS-CoV-2. The EVs embedded with engineered ACE2 (EVs-ACE2) were prepared; the EVs-ACE2 were derived from an engineered cell line with stable ACE2 expression. The potential effect of the EVs-ACE2 on anti-SARS-CoV-2 was demonstrated by both in vitro and in vivo neutralization experiments using the pseudovirus with the S protein (S-pseudovirus). EVs-ACE2 can inhibit the infection of S-pseudovirus in various cells, and importantly, the mice treated with intranasal administration of EVs-ACE2 can suppress the entry of S-pseudovirus into the mucosal epithelium. Therefore, the intranasal EVs-ACE2 could be a preventive medicine to protect from SARS-CoV-2 infection. This EVs-based strategy offers a potential route to COVID-19 drug development.

A proof of concept for neutralizing antibody-guided vaccine design against SARS-CoV-2.

Mutations and transient conformational movements of the receptor binding domain (RBD) that make neutralizing epitopes momentarily unavailable present immune escape routes for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To mitigate viral escape, we developed a cocktail of neutralizing antibodies (NAbs) targeting epitopes located on different domains of spike (S) protein. Screening of a library of monoclonal antibodies generated from peripheral blood mononuclear cells of COVID-19 convalescent patients yielded potent NAbs, targeting the N-terminal domain (NTD) and RBD domain of S, effective at nM concentrations. Remarkably, a combination of RBD-targeting NAbs and NTD-binding NAbs, FC05, enhanced the neutralization potency in cell-based assays and an animal model. Results of competitive surface plasmon resonance assays and cryo-electron microscopy (cryo-EM) structures of antigen-binding fragments bound to S unveil determinants of immunogenicity. Combinations of immunogens, identified in the NTD and RBD of S, when immunized in rabbits and macaques, elicited potent protective immune responses against SARS-CoV-2. More importantly, two immunizations of this combination of NTD and RBD immunogens provided complete protection in macaques against a SARS-CoV-2 challenge, without observable antibody-dependent enhancement of infection. These results provide a proof of concept for neutralization-based immunogen design targeting SARS-CoV-2 NTD and RBD.

[The Clinical Characteristics and Influencing Factors of Patients with Severe COVID-19].

OBJECTIVE: To investigate the clinical characteristic of coagulation, possible causes and countermeasures of patients with severe corona virus disease 2019 (COVID-19). METHODS: The clinical data of the 142 patients diagnosed as COVID-19 at Wuhan Third Hospital in Wuhan, China, from February 10 to February 16, 2020 were collected and analyzed retrospective. Among the patients, 17 cases of dead patients were divided into observe group, and 125 cases of cured patients were divided into control group. The clinical characteristics, laboratory tests, influencing factors, anticoagulant therapy, embolization and bleeding events of the two groups were observed. RESULTS: The average hospital stay time in 142 patients was 22 d. For the 17 dead patients in the observe group, the average hospital stay time was 9.9 d, and the D-dimer, prothrombin time, WBC count and Padua score of the patients in the observe group were significantly higher as compared with the patients in the control group. PT(OR=1.064, 95%CI 1.012-1.119) and D-D(OR=1.045, 95%CI 1.027-1.064) were the independent risk factors that causing the death of COVID-19 patients. Among the patients, 36(25.4%) patients received low-molecular-weight heparin for anticoagulant therapy, with the average course of 9.6 d. The cumulative incidence of the embolism of the patients in the observe group was 7（41.2%）, while 2(11.8%) patients developed to deep vein thrombosis (DVT) and pulmonary embolism (PE), 3 (17.6%) patients occurred acute cerebral infarction and 2 (11.8%) patients occurred acute myocardial infarction. 3 (17.6%) dead patients revealed dominant disseminated intravascular coagulation (DIC). CONCLUSION: Most patients with severe COVID-19 shows a variety of risk factors for thrombus, and those with coagulation dysfunction shows a high dead rate and rapid disease progression. Therefore, coagulation indicators should be dynamically monitored, and mechanical and drug prevention should be actively carried out.