Efficacy and Safety of Ensitrelvir for Asymptomatic or Mild COVID-19: An Exploratory Analysis of a Multicenter, Randomized, Phase 2b/3 Clinical Trial.

BACKGROUND: This phase 2b/3, randomized, placebo-controlled trial explored the efficacy and evaluated the safety of ensitrelvir. This trial involved individuals with asymptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and patients with mild symptoms of coronavirus disease 2019 (COVID-19). METHODS: The trial was conducted at 57 medical institutions in Japan, South Korea, and Vietnam (study period: January 6-August 14, 2022). Eligible participants were randomized (1:1:1) to the ensitrelvir 125-mg, ensitrelvir 250-mg, or placebo group, received the allocated intervention orally, and were followed up until Day 28. Participants self-rated the severity of 14 typical COVID-19 symptoms and recorded the data in an electronic diary. RESULTS: In total, 572 participants (194, 189, and 189 in the ensitrelvir 125-mg, ensitrelvir 250-mg, and placebo groups, respectively) were included in the intention-to-treat population. Ensitrelvir 125-mg group observed a 77% reduction in the risk of developing any of the 14 COVID-19 symptoms or fever and a 29% reduction in the risk of worsening of such symptoms or fever versus placebo (statistically nonsignificant). The viral RNA, viral titer, and time to infectious viral clearance observed a statistically significant decrease versus placebo. Most treatment-related adverse events (TEAEs) were mild to moderate in severity, and the most common TEAE observed across groups was a decrease in high-density lipoprotein. CONCLUSIONS: Our exploratory results suggest a potential reduction in the risk of development or worsening of COVID-19 symptoms with ensitrelvir. Ensitrelvir showed antiviral efficacy and was well tolerated. TRIAL REGISTRATION: Japan Registry of Clinical Trials identifier: jRCT2031210350.

Scaling up a brief alcohol intervention to prevent HIV infection in Vietnam: a cluster randomized, implementation trial.

BACKGROUND: Evidence-based interventions (EBIs) often address normative behaviors. If a behavior is also common among clinicians, they may be skeptical about the necessity or effectiveness of an EBI. Alternatively, clinicians' attitudes and behaviors may be misaligned, or they may lack the knowledge and self-efficacy to deliver the EBI. Several EBIs address unhealthy alcohol use, a common and often culturally acceptable behavior. But unhealthy alcohol use may be particularly harmful to people with HIV (PWH). Here, we present an implementation trial using an experiential implementation strategy to address clinicians' knowledge, attitudes, and behaviors. Clinicians receive the experiential intervention before they begin delivering an evidence-based brief alcohol intervention (BAI) to PWH with unhealthy alcohol use. METHODS: Design: In this hybrid type 3 implementation-effectiveness cluster randomized controlled trial, ART clinics (n = 30) will be randomized 1:1 to facilitation, a flexible strategy to address implementation barriers, or facilitation plus the experiential brief alcohol intervention (EBAI). In the EBAI arm, clinicians, irrespective of their alcohol use, will be offered the BAI as experiential learning. EBAI will address clinicians' alcohol-related attitudes and behaviors and increase their knowledge and confidence to deliver the BAI. PARTICIPANTS: ART clinic staff will be enrolled and assessed at pre-BAI training, post-BAI training, 3, 12, and 24 months. All PWH at the ART clinics who screen positive for unhealthy alcohol use will be offered the BAI. A subset of PWH (n = 810) will be enrolled and assessed at baseline, 3, and 12 months. OUTCOMES: We will compare implementation outcomes (acceptability, fidelity, penetration, costs, and sustainability) and effectiveness outcomes (viral suppression and alcohol use) between the two arms. We will assess the impact of site-level characteristics on scaling-up the BAI. We will also evaluate how experiencing the BAI affected clinical staff's alcohol use and clinic-level alcohol expectations in the EBAI arm. DISCUSSION: This trial contributes to implementation science by testing a novel strategy to implement a behavior change intervention in a setting in which clinicians themselves may engage in the behavior. Experiential learning may be useful to address normative and difficult to change lifestyle behaviors that contribute to chronic diseases. TRIAL REGISTRATION: NCT06358885 (04/10/2024), https://clinicaltrials.gov/study/NCT06358885 .

A "What Matters Most" approach to investigating intersectional stigma toward HIV and cancer in Hanoi, Vietnam.

BACKGROUND: Vietnam is experiencing a growing burden of cancer, including among people living with HIV. Stigma acts as a sociocultural barrier to the prevention and treatment of both conditions. This study investigates how cultural notions of "respected personhood" (or "what matters most") influence manifestations of HIV-related stigma and cancer stigma in Hanoi, Vietnam. METHODS: Thirty in-depth interviews were conducted with people living with HIV in Hanoi, Vietnam. Transcripts were thematically coded via a directed content analysis using the What Matters Most conceptual framework. Coding was done individually and discussed in pairs, and any discrepancies were reconciled in full-team meetings. RESULTS: Analyses elucidated that having chu tín-a value reflecting social involvement, conscientiousness, and trustworthiness-and being successful (eg, in career, academics, or one's personal life) are characteristics of respected people in this local cultural context. Living with HIV and having cancer were seen as stigmatized and interfering with these values and capabilities. Intersectional stigma toward having both conditions was seen to interplay with these values in some ways that had distinctions compared with stigma toward either condition alone. Participants also articulated how cultural values like chu tín are broadly protective against stigmatization and how getting treatment and maintaining employment can help individuals resist stigmatization's most acute impacts. CONCLUSIONS: HIV-related and cancer stigma each interfere with important cultural values and capabilities in Vietnam. Understanding these cultural manifestations of these stigmas separately and intersectionally can allow for greater ability to measure and respond to these stigmas through culturally tailored intervention.

Clinical characteristics and outcomes of patients with Herpes Simplex Encephalitis in Vietnam: a retrospective study.

BACKGROUND: Herpes simplex encephalitis (HSE) is an important central nervous infection with severe neurological sequelae. The aim of this study was to describe clinical characteristic and outcomes of patients with HSE in Vietnam. METHODS: This was a retrospective study of 66 patients with herpes simplex encephalitis who admitted to the National Hospital for Tropical Diseases, Hanoi, Vietnam from 2018 to 2021. The detection of herpes simplex virus (HSV) in cerebrospinal fluid was made by the real-time PCR assay. We reported the clinical manifestation on admission and evaluated clinical outcomes at the hospital discharge by modified Rankin Scale (mRS). Multivariate logistic regression analysis was used to analyze the independent risk factors of severe outcomes. RESULTS: Of the 66 patients with laboratory confirmed HSE, the median age was 53 years (IQR 38-60) and 44 patients (69.7%) were male. The most common manifestations included fever (100%), followed by the consciousness disorder (95.5%). Other neurological manifestation were seizures (36.4%), memory disorders (31.8%), language disorders (19.7%) and behavioral disorders (13.6%). Conventional magnetic resonance imaging (MRI) showed 93.8% patients with temporal lobe lesions, followed by abnormalities in insula (50%), frontal lobe (34.4%) and 48.4% of patients had bilateral lesions. At discharge, 19 patients (28.8%) completely recovered, 15 patients (22.7%) had mild sequelae, 28 patients (42.4%) had moderate to severe sequelae. Severe neurological sequelae were memory disorders (55.8%), movement disorders (53.5%), language disorders (30.2%). Multivariate logistic regression analysis showed that Glasgow score decrement at admission, seizures, and time duration from onset of symptoms to the start of Acyclovir treatment > 4 days were independent factors associated with severe outcomes in HSE patients. CONCLUSION: Glasgow score decrement, seizures and delay treatment with Acyclovir were associated with the poor outcome of patients with HSE.

Investigating demic versus cultural diffusion and sex bias in the spread of Austronesian languages in Vietnam.

Austronesian (AN) is the second-largest language family in the world, particularly widespread in Island Southeast Asia (ISEA) and Oceania. In Mainland Southeast Asia (MSEA), groups speaking these languages are concentrated in the highlands of Vietnam. However, our knowledge of the spread of AN-speaking populations in MSEA remains limited; in particular, it is not clear if AN languages were spread by demic or cultural diffusion. In this study, we present and analyze new data consisting of complete mitogenomes from 369 individuals and 847 Y-chromosomal single nucleotide polymorphisms (SNPs) from 170 individuals from all five Vietnamese Austronesian groups (VN-AN) and five neighboring Vietnamese Austroasiatic groups (VN-AA). We found genetic signals consistent with matrilocality in some, but not all, of the VN-AN groups. Population affinity analyses indicated connections between the AN-speaking Giarai and certain Taiwanese AN groups (Rukai, Paiwan, and Bunun). However, overall, there were closer genetic affinities between VN-AN groups and neighboring VN-AA groups, suggesting language shifts. Our study provides insights into the genetic structure of AN-speaking communities in MSEA, characterized by some contact with Taiwan and language shift in neighboring groups, indicating that the expansion of AN speakers in MSEA was a combination of cultural and demic diffusion.

Understanding veterinary drug shop workers' knowledge and practices to identify drivers of antibiotic use in Vietnamese livestock farms.

BACKGROUND: Antimicrobial resistance (AMR) is a One Health issue and a major threat to animal and human health. Antibiotic use (ABU) drives AMR development, and several hotspots for ABU, and AMR, in livestock have been identified in Southeast Asia, including Vietnam. There are often multiple drivers of ABU at farms, and to identify all of them there is a need to look beyond farm level. OBJECTIVES: The overall aim of this study was to identify routines and/or competencies, related to antibiotic sales, among veterinary drug shop workers that may be improved in order to decrease the medically non-rational use of antibiotics in livestock production. METHODS: A questionnaire-based survey was conducted at 50 veterinary drug shops in northern Vietnam. RESULTS: Results showed high education and knowledge levels. According to the respondents, antibiotic treatment advice was almost always provided to the farmers, and the recommended treatment was most commonly based on recommendations for the specific disease. However, farmers had almost never had their animals properly diagnosed. Antibiotics were the most sold drug category, penicillins being the most common. Several broad-spectrum antibiotics were also quite frequently sold. Further, >50% of respondents recommended antibiotics for disease prevention. CONCLUSIONS: Even though education and knowledge levels might be high, several challenges can prevent drug shop workers from contributing to more prudent ABU at farms, for example, lack of proper diagnosis, commercial interests and individual farmer motives, often in combination with poor compliance to regulations.

Circulating cell-free RNA in blood as a host response biomarker for detection of tuberculosis.

Tuberculosis (TB) remains a leading cause of death from an infectious disease worldwide, partly due to a lack of effective strategies to screen and triage individuals with potential TB. Whole blood RNA signatures have been tested as biomarkers for TB, but have failed to meet the World Health Organization's (WHO) optimal target product profiles (TPP). Here, we use RNA sequencing and machine-learning to investigate the utility of plasma cell-free RNA (cfRNA) as a host-response biomarker for TB in cohorts from Uganda, Vietnam and Philippines. We report a 6-gene cfRNA signature, which differentiates TB-positive and TB-negative individuals with AUC = 0.95, 0.92, and 0.95 in test, training and validation, respectively. This signature meets WHO TPPs (sensitivity: 97.1% [95% CI: 80.9-100%], specificity: 85.2% [95% CI: 72.4-100%]) regardless of geographic location, sample collection method and HIV status. Overall, our results identify plasma cfRNA as a promising host response biomarker to diagnose TB.

Mitigating machine learning bias between high income and low-middle income countries for enhanced model fairness and generalizability.

Collaborative efforts in artificial intelligence (AI) are increasingly common between high-income countries (HICs) and low- to middle-income countries (LMICs). Given the resource limitations often encountered by LMICs, collaboration becomes crucial for pooling resources, expertise, and knowledge. Despite the apparent advantages, ensuring the fairness and equity of these collaborative models is essential, especially considering the distinct differences between LMIC and HIC hospitals. In this study, we show that collaborative AI approaches can lead to divergent performance outcomes across HIC and LMIC settings, particularly in the presence of data imbalances. Through a real-world COVID-19 screening case study, we demonstrate that implementing algorithmic-level bias mitigation methods significantly improves outcome fairness between HIC and LMIC sites while maintaining high diagnostic sensitivity. We compare our results against previous benchmarks, utilizing datasets from four independent United Kingdom Hospitals and one Vietnamese hospital, representing HIC and LMIC settings, respectively.

Phenotyping chronic respiratory diseases with airways obstruction.

Given the high prevalence of asthma-chronic obstructive pulmonary disease overlap (ACO) in Vietnam, there is an urgent need to establish a simplified strategy for categorising patients as either having asthma or chronic obstructive pulmonary disease (COPD). This classification would streamline the application of treatment recommendations outlined by the Global Initiative for Asthma (GINA) and the Global Initiative for Chronic Obstructive Lung Disease (GOLD).Patients with obstructive lung function were classified as having COPD, asthma, or ACO based on GINA/GOLD guidelines. We hypothesised that ACO-like asthma (ACO-A) would present with positive skin prick tests (SPTs) or early onset of symptoms without a history of tuberculosis (TB), while those with ACO-like COPD (ACO-B) would exhibit negative SPTs and late onset of symptoms and/or a history of TB.Among 235 patients, the prevalence of asthma, ACO-A, ACO-B, and COPD was respectively 21%, 22%, 17%, and 40%. Allergic history, rhinitis, and childhood asthma were associated with ACO-A, while high cumulative smoking was correlated with ACO-B. Socio-economic and demographic parameters, medical history, clinical features, smoking habits, lung function, and para-clinical investigations significantly differed between "all asthma" (i.e., individuals with asthma combined with ACO-A) and "all COPD" (i.e., individuals with COPD combined with ACO-B).Based on SPTs, history of TB, and onset age, ACO patients may be defined as people with asthma or COPD..

Assessment of microplastic presence in coastal environments and organisms of Da Nang, Vietnam.

This study investigates the presence of microplastics (MPs) in seawater, sediments, and organisms along the coastal areas of Da Nang, Vietnam. The results obtained revealed MP concentrations ranging from 111 to 304 MPs/L in seawater and 2267 to 4600 MPs/kg in sediment. In organisms such as oysters, mussels, crabs, snails, and fish, MP levels ranged from 1.8 to 17.3 MPs/g (wet weight). Fiber MPs were found to be predominant across seawater, sediment, and organisms. The study identified eight, ten, and eleven types of MPs in seawater, sediment, and organisms, respectively, with Nylon, Polytetrafluoroethylene (PTFE), and Ethylene vinyl alcohol (EVOH) being the most prevalent. Notably, MP concentrations were significantly higher in benthic organisms such as oysters, mussels, and crabs compared to fish (t-test, p < 0.05), suggesting habitat dependency. Similar concentrations, shapes, and types of MPs in seawater, sediments, and organisms demonstrate a tendency for MP accumulation in aquatic organisms within the marine environment.

The prescription of beta-blockers in older patients with heart failure with reduced ejection fraction: an observational study in Vietnam.

This study in older hospitalized patients with heart failure with reduced ejection fraction (HFrEF) aimed to examine the prevalence of beta-blocker prescription and its associated factors. A total of 190 participants were recruited from July 2019 to July 2020. The inclusion criteria included: (1) aged ≥ 60 years, (2) having a diagnosis of chronic HFrEF in the medical records, (3) hospitalized for at least 48 h. The participants had a mean age of 75.5 ± 9.1, and 46.8% were female. Of these, 55.3% were prescribed beta-blockers during admission. To explore the factors associated with beta-blocker prescription, multivariable logistic regression analysis was applied and the results were presented as odds ratios (OR) and 95% confidence intervals (CI). On multivariate logistic regression models, higher NYHA classes (OR 0.49, 95%CI 0.26-0.94), chronic obstructive pulmonary disease (OR 0.17, 95% CI 0.04-0.85), chronic kidney disease (OR 0.40, 95% CI 0.19-0.83), and heart rate under 65 (OR 0.34, 95% CI 0.12-0.98) were associated with a reduced likelihood of prescription. In this study, we found a low rate of beta-blocker prescriptions, with only around half of the participants being prescribed beta-blockers. Further studies are needed to examine the reasons for the under-prescription of beta-blockers, and to evaluate the long-term benefits of beta-blockers in elderly patients with HFrEF in this population.

Molecular detection, risk factors, and phylogenetic analysis of tick-borne pathogens in dogs from northern Vietnam.

In tropical regions, numerous tick-borne pathogens (TBPs) play a crucial role as causative agents of infectious diseases in humans and animals. Recently, the population of companion and pet dogs has significantly increased in Vietnam; however, information on the occurrence of TBPs is still limited. The objectives of this investigation were to determine the occurrence rate, risk factors, and phylogenetic characteristics of TBPs in dogs from northern Vietnam. Of 341 blood samples tested by PCR, the total infection of TBPs was 73.9% (252/341). Babesia vogeli (18SrRNA gene - 30.5%) was detected most frequently in studied dogs followed by Rickettsia spp. (OmpA gene - 27%), Anaplasma platys (groEL gene - 22%), Bartonella spp. (16SrRNA - 18.8%), Mycoplasma haemocanis (16SrRNA - 9.4%) and Hepatozoon canis (18SrRNA gene - 1.2%), respectively. All samples were negative for Ehrlichia canis and Anaplasma phagocytophylum. Co-infection was detected in 31.4% of the samples (107/341) of which, A. platys/Bartonella spp. (34/94,10%), Rickettsia spp./B. vogeli (19/94, 5.6%), and M. haemocanis/B. vogeli (19/94, 5.6%) were recorded as the three most frequent two species of co-infection types. Statistical analysis revealed a significant correlation between TBP infection and several host variables regarding age, breed, and living area in the current study. The recent findings reported herein, for the first time in Vietnam, are essential for local veterinarians when considering the appropriate approaches for diagnosing these diseases. Furthermore, this data can be used to establish control measures for future surveillance and prevention strategies against canine TBPs in Vietnam.

An exploration of meteorological effects on PM2.5 air quality in several provinces and cities in Vietnam.

Linking meteorology and air pollutants is a key challenge. The study investigated meteorological effects on PM2.5 concentration using the advanced convergent cross mapping method, utilizing hourly PM2.5 concentration and six meteorological factors across eight provinces and cities in Vietnam. Results demonstrated that temperature (ρ = 0.30) and radiation (ρ = 0.30) produced the highest effects, followed by humidity (ρ = 0.28) and wind speed (ρ = 0.24), while pressure (ρ = 0.22) and wind direction (ρ = 0.17) produced the weakest effects on PM2.5 concentration. Comparing the ρ values showed that temperature, wind speed, and wind direction had greater impacts on PM2.5 concentration during the dry season whereas radiation had a more influence during the wet season; Southern stations experienced larger meteorological effects. Temperature, humidity, pressure, and wind direction had both positive and negative influences on PM2.5 concentration, while radiation and wind speed mostly had negative influences. During PM2.5 pollution episodes, there was more contribution of meteorological effects on PM2.5 concentration indicated by ρ values. At contaminated levels, humidity (ρ = 0.45) was the most dominant factor affecting PM2.5 concentration, followed by temperature (ρ = 0.41) and radiation (ρ = 0.40). Pollution episodes were pointed out to be more prevalent under higher humidity, higher pressure, lower temperature, lower radiation, and lower wind speed. The ρ calculation also revealed that lower temperature, lower radiation, and higher humidity greatly accelerated each other under pollution episodes, further enhancing PM2.5 concentration. The findings contributed to the literature on meteorology and air pollution interaction.

Reassessment of pore occlusion in some diatom taxa with re-evaluation of Placoneis Mereschkowsky (Bacillariophyceae: Cymbellales) and description of two new genera.

In this article, the history and taxonomy of Placoneis gastrum, the type species of the genus Placoneis, was discussed. We investigated the structure of pore occlusions in Placoneis and related genera. As a result, we propose a new classification for tectulum-like types of pore occlusions. The new classification is congruent with previously-published and newly-constructed phylogenies based on molecular data. Based on the different structures of the pore occlusions, species of Placoneis are transferred to Witkowskia gen. nov. Hence, 168 new combinations are introduced. A new diatom species, with a similar morphology to Placoneis flabellata, was discovered in Bac Kan Province, Vietnam. It is described in this article as Chudaevia densistriata sp. nov. Placoneis flabellata is transferred to Chudaevia gen. nov. We also illustrate Placoneis flabellata herein and compare it to Chudaevia densistriata sp. nov. An unknown diatom, similar to Placoneis coloradensis, was discovered in Chukotka, Russia. It is introduced as Placoneis elinae sp. nov. below. Additionally, we discuss the distribution of some species of Witkowskia gen. nov. and Chudaevia gen. nov.

Lifestyle practices and associated factors among adults with hypertension: Conquering Hypertension in Vietnam-solutions at the grassroots level study.

BACKGROUND: Vietnam is experiencing an increasing prevalence of hypertension in its adult population. In addition to medical therapy, modifying adverse lifestyle practices is important for effective blood pressure control. There are limited data on unhealthy lifestyle practices in patients with chronic diseases, however, particularly among hypertensive patients living in rural Vietnam. Our study objectives were to examine the prevalence of unhealthy lifestyle practices and associated factors among rural Vietnamese adults with uncontrolled hypertension. METHODS: Data from the baseline survey of a cluster randomized trial among hypertensive Vietnamese adults (2017-2022) were utilized. Information on unhealthy lifestyle practices including smoking, excessive alcohol consumption, physical inactivity, and inadequate fruit and vegetable intake was collected from study participants. The primary study outcome was having ≥2 unhealthy lifestyle practices. A multivariable logistic regression model was used to examine factors associated with the primary study outcome. RESULTS: The mean age of the 671 patients was 67 years and 45.0% were men. Nearly three out of every four participants had one or fewer unhealthy practices, 24.0% had two, and 3.3% had three or all four unhealthy lifestyle practices. Men, individuals who did unpaid work or were unemployed, and individuals with hypertension level III were more likely to have ≥2 unhealthy lifestyle practices, whereas individuals with higher education were less likely to have ≥2 unhealthy lifestyle practices compared with respective comparison groups. CONCLUSIONS: We observed a high prevalence of unhealthy lifestyle practices among rural Vietnamese patients with uncontrolled hypertension. Several demographic factors were associated with a greater number of unhealthy lifestyle practices. Newer interventions and educational programs encouraging lifestyle modification practices are needed to control hypertension among adults living in rural settings of Vietnam.

Willingness to Pay for a Quality-Adjusted Life Year among Gastrointestinal Cancer Patients at a Tertiary Hospital of Vietnam, 2022.

BACKGROUND: Gastrointestinal (GI) cancer burden in Asia is increasing, and Vietnam is no exception. Assessing the affordability of achieving a quality-adjusted life year (QALY) in gastrointestinal cancer patients Vietnam, as well as identifying predictors of willingness to pay (WTP) per QALY, is crucial to decision-making around medical intervention prioritization and performing medical technology assessments for these cancers. OBJECTIVES: Our study aimed to estimate WTP/QALY gained and associated factors among patients diagnosed with GI cancer at a tertiary hospital in Hue, Vietnam. METHODS: A cross-sectional descriptive study, using contingent valuation methodology was conducted among 231 patients at tertiary hospital in 2022. A double limited dichotomous choice and the EQ-5D-5L were utilised to estimate WTP and QALY, respectively. Quantile regression was applied to determine predictors of WTP/QALY. RESULTS: The mean and median maximum WTP/QALY gained among GI patients was $15,165.6 (42,239.6) and $4,365.6 (IQR: 1,586.5-14,552.0), respectively, which was equal to 3.68 times the 2022 gross domestic product (GDP) per capita in Vietnam.  Additionally, cancer severity was found to have a significant impact  on WTP per QALY gained, with a higher amount identified among patients with earlier stages of GI cancer. Furthermore, living in an urban dwelling and patients' treatment modalities were significantly associated with WTP/QALY. CONCLUSION: Evidence from our study can be used to inform how decision-makers in Vietnam to determine the cost-effectiveness of GI cancer interventions.

Distribution and Population Genetic Structure of the Hau Giang Medaka, Oryzias haugiangensis, Along the East Coast of the Indochinese Peninsula.

The east coast of the Indochinese Peninsula is a well-known transition zone from subtropical to tropical systems, yet only a small number of studies have been conducted on the biogeography and phylogeography of aquatic organisms in this region. The Hau Giang medaka, Oryzias haugiangensis, was originally described from the Mekong Delta in southern Vietnam, and later reported also from southeastern Thailand, west of the Mekong Delta region. However, the species' full geographic range and population genetic structures remain unknown. Field surveys showed a widespread distribution of this species along the east coast of the Indochinese Peninsula, as far as northern Vietnam. A mitochondrial gene phylogeny and population genetic structure analysis using genome-wide single nucleotide polymorphisms revealed that the populations of O. haugiangensis are highly structuralized along the east coast of Vietnam, with the southernmost Mekong Delta population clearly separated from three populations north of central Vietnam. Further field collections are necessary to determine the boundary between the southern and northern populations, and the presence or absence of a hybrid zone.

Variation in Ventral Coloration Pattern and Aposematism in Tropical Warty Newts.

Aposematic coloration plays a crucial role in animal defense, and it is shaped by a complex interplay of factors such as physiological limitations and sexual and natural selection. Warty newts within the genus Paramesotriton exhibit significant variation in ventral coloration. In this study, we quantified the percentage of red ventral area to investigate aposematic ventral coloration in Paramesotriton deloustali and P. guangxiensis across eight populations in northern Vietnam. To assess the interaction between predators and the aposematic signals, we conducted experiments employing three types of clay replicas of newts: dorsal, red ventral, and black ventral models. Our findings revealed a significant variation in the red ventral area among different populations. Additionally, a significant correlation was detected between the red ventral area of the newt and the annual temperature range. In clay model experiments, a significant difference in predator attack rates was observed between dorsal and ventral clay models. Interestingly, there was no significant difference in attack rates between red and black ventral types. Our study suggested that the variation in the red ventral area of warty newts is probably influenced by multiple factors, including genetic constraints, sex, ambient environment, and diet. Furthermore, our results supported the effectiveness of displaying aposematic coloration as an antipredator defense mechanism in warty newts. However, variations in body size and the pressure of mammal predation might not play a significant role in determining aposematic coloration.

A SARS-CoV-2 recombinant spike protein vaccine (S-268019-b) for COVID-19 prevention during the Omicron-dominant period: A phase 3, randomised, placebo-controlled clinical trial.

Clinical trials of new vaccines based on existing variants of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) are often impacted by the emergence of new virus variants. We evaluated the efficacy, immunogenicity, and safety of S-268019-b, a recombinant spike protein subunit vaccine based on the ancestral strain, for preventing symptomatic coronavirus disease 2019 (COVID-19) during the Omicron (BA.2)-dominant period in Vietnam. In this multicentre, phase 3, randomised (2:1), observer-blind, placebo-controlled crossover study, participants received 2 intramuscular doses (28 days apart) of either 10 µg of S-268019-b (Recombinant S-protein vaccine) or placebo. The primary endpoint was incidence of laboratory-confirmed symptomatic COVID-19 before crossover, with onset within 14 days following the second dose, in participants who were seronegative and reverse transcription polymerase chain reaction (RT-PCR)-negative at baseline. The secondary endpoints included immunogenicity and safety. In total, 8,594 participants were randomised (S-268019-b [n = 5,727]; placebo [n = 2,867]). Vaccine efficacy versus placebo was 39·1 % (95 % confidence interval [CI]:26·6-49·5; one-sided P = 0·0723). The incidence rate (95 % CI) of symptomatic COVID-19 was 776·41/1,000 person-years (682·04-880·19) in the S-268019-b group and 1272·87/1,000 person-years (1101·32-1463·57) in the placebo group. The geometric mean titres (95 % CI) of the SARS-CoV-2 neutralising antibody increased on Day 57 versus baseline with S-268019-b (34·66 [27·04-44·41] versus 2·50 (non-estimable) but not with placebo. There were no safety concerns regarding S-268019-b. S-268019-b did not demonstrate the targeted efficacy threshold against symptomatic COVID-19; however, findings were comparable with other prophylactic vaccines based on ancestor strain during the Omicron-dominant period. S-268019-b demonstrated immunogenicity and was well-tolerated. ClinicalTrials.gov identifier: NCT05212948.

Socio-behavioural factors influencing meat intake and meat reduction intention in Vietnam and Switzerland.

Meat consumption is declining in developed countries but increasing in emerging countries. This study, for the first time, compares the socio-behavioural factors influencing individuals' meat consumption level and meat reduction intention between Vietnam, an emerging economy and Switzerland, a developed country. Online consumer surveys were conducted in late 2022, yielding 552 usable replies from Switzerland and 592 from Vietnam for this study. Drawing upon an extended Protection Motivation Theory and using structural equation modelling, we found similarities as well as differences in the determinants of meat consumption behaviour. Perceived health risks of meat overconsumption, self-efficacy of meat reduction, attitude toward ethical and environmental issues, and pressure from family members' reluctance to change diet drove the intention to reduce meat in both countries. Meat attachment emerges as the most important determinant of meat consumption level in not only Switzerland but also Vietnam and thus presents the largest barrier to meat reduction. The association between response cost of eating less meat and intention to reduce meat was negative in Switzerland but positive in Vietnam. Self-efficacy of meat consumption reduction influenced meat consumption level solely in Switzerland. Ethical and environmental attitudes significantly facilitated meat reduction intention of Swiss respondents only, reflecting cultural differences. Policy implications were discussed.