Real-Time Magnetic Tracking and Diagnosis of COVID-19 via Machine Learning (preprint)

The COVID-19 pandemic underscored the importance of reliable, noninvasive diagnostic tools for robust public health interventions. In this work, we fused magnetic respiratory sensing technology (MRST) with machine learning (ML) to create a diagnostic platform for real-time tracking and diagnosis of COVID-19 and other respiratory diseases. The MRST precisely captures breathing patterns through three specific breath testing protocols: normal breath, holding breath, and deep breath. We collected breath data from both COVID-19 patients and healthy subjects in Vietnam using this platform, which then served to train and validate ML models. Our evaluation encompassed multiple ML algorithms, including support vector machines and deep learning models, assessing their ability to diagnose COVID-19. Our multi-model validation methodology ensures a thorough comparison and grants the adaptability to select the most optimal model, striking a balance between diagnostic precision with model interpretability. The findings highlight the exceptional potential of our diagnostic tool in pinpointing respiratory anomalies, achieving over 90% accuracy. This innovative sensor technology can be seamlessly integrated into healthcare settings for patient monitoring, marking a significant enhancement for the healthcare infrastructure.

A Multi-Epitope/CXCL11 Prime/Pull Coronavirus Mucosal Vaccine Boosts the Frequency and the Function of Lung-Resident CD4+ and CD8+ Memory T Cells and Protects Against COVID-19-like Symptoms and Death Caused by SARS-CoV-2 infection (preprint)

The pandemic of the coronavirus disease 2019 (COVID-19) has created the largest global health crisis in almost a century. Following exposure to SARS-CoV-2, the virus particles replicate in the lungs, induce a cytokine storm and potentially cause life-threatening inflammatory disease. Low frequencies of function SARS-CoV-2-specific CD4+ and CD8+ T cells in the lungs of COVID-19 patients were associated with severe cases of COVID-19. The apparent low level of T cell-attracting CXCL9, CXCL10, and CXCL11 chemokines in infected lungs may not be sufficient enough to assure the sequestration and/or homing of CD4+ and CD8+ T cells from the circulation into infected lungs. We hypothesize that a Coronavirus vaccine strategy that boosts the frequencies of functional SARS-CoV-2-specific CD4+ and CD8+ T cells in the lungs would lead to better protection against SARS-CoV-2 infection, COVID19-like symptoms, and death. In the present study, we designed and pre-clinically tested the safety, immunogenicity, and protective efficacy of a novel multi-epitope//CXCL11 prime/pull mucosal Coronavirus vaccine. This prime/pull vaccine strategy consists of intranasal delivery of a lung-tropic adeno-associated virus type 9 (AAV-9) vector that incorporates highly conserved human B, CD4+ CD8+ cell epitopes of SARS-CoV-2 (prime) and pulling the primed B and T cells into the lungs using the T cell attracting chemokine, CXCL-11 (pull). We demonstrated that immunization of HLA-DR*0101/HLA-A*0201/hACE2 triple transgenic mice with this multi-epitope//CXCL11 prime/pull Coronavirus mucosal vaccine: (i) Increased the frequencies of CD4+ and CD8+ TEM, TCM, and TRM cells in the lungs; and (ii) reduced COVID19-like symptoms, lowered virus replication, and prevented deaths following challenge with SARS-CoV-2. These findings discuss the importance of bolstering the number and function of lung-resident memory CD4+ and CD8+ T cells for better protection against SARS-CoV-2 infection, COVID-19-like symptoms, and death.

SG-APSIC1126: Controlling SARS-CoV-2 infection in inpatients through a grouping system at Ho Chi Minh Children's Hospital 1 in Vietnam

Objectives: At the onset of COVID-19, whenever SARS-CoV-2 was detected at Children's Hospital 1 (CH1), the related department or building was closed for extensive tracing, testing, and medical isolation. This process disrupted hospital activities, reduced the efficiency of patient care, and used medical resources. To address this problem, CH1 implemented a system of grouping inpatients to color-coded areas from June to December 2021. Methods: In this retrospective study, we describe the system of grouping inpatients to color-coded areas based on SARS-CoV-2 test result at a 1,600-bed, national pediatric hospital in Ho Chi Minh City. Results: Inpatients were first separated into those with or without respiratory symptoms, and secondly to different color-coded areas based on SARS-CoV-2 test result and hospitalization length: red zone (days 1–3), orange zone (days 3–7), and green zone (day 7 onward). Prior to admission, all patients were tested with a SARS-CoV-2 rapid diagnostic test. If negative, the patient was admitted to the red zone. On days 3 and 7 of hospitalization, the patient was tested using a pooled RT-PCR method. Patients negative on day 3 were relocated to the orange zone;patients negative on day 7 were relocated to the green zone. A patient with a positive test result at any time point was transferred to a COVID-19 zone. One caregiver was allowed to stay with 1 patient with similar testing regimen. A mobile transportation team was set up to deliver food and other necessities;thus, movement was restricted and interaction was prevented among zones. After this system was implemented, COVID-19 cases were detected early, with most positive cases in the red zone (19.6%) and the orange zone (2.8%), with only 1 case in the green zone (0.7%). Conclusions: The system of grouping patients to color-coded areas helped prevent SARS-CoV-2 transmission within the hospital, allowing undisrupted operation.

Spatiotemporal Evolution of SARS-CoV-2 Alpha and Delta Variants during Large Nationwide Outbreak of COVID-19, Vietnam, 2021.

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions.

The Role of Self-Compassion on Psychological Well-Being and Life Satisfaction of Vietnamese Undergraduate Students During the COVID-19 Pandemic: Hope as a Mediator.

The simultaneous occurrence of the COVID-19 pandemic and the transition to adulthood have posed particular obstacles to university students' mental health. However, it remains unclear whether hope promotes mental health in the relationship between self-compassion, psychological well-being, and life satisfaction. Therefore, this study investigated the role of hope as a mediator in the relationship between self-compassion, psychological well-being, and life satisfaction among Vietnamese undergraduate students in the context of the COVID-19 pandemic. Participants consisted of 484 students (aged 18-24) from several universities in Vietnam. To measure the four variables in the research model, we opted for the Self-Compassion Scale, the State Hope Scale, the World Health Organization 5-item Well-Being Index, and the Satisfaction With Life Scale. The results showed that (1) self-compassion was significantly positively correlated with psychological well-being, (2) self-compassion was not correlated with life satisfaction, (3) hope was a mediator of the relationship between self-compassion and psychological well-being, and (4) hope was a mediator of the relationship between self-compassion and life satisfaction. These findings suggest interventions on self-compassion to enhance hope and subsequently increase students' mental health, which offers colleges, psychologists, and psychiatrists a guideline to cope with harmful psychological implications during the COVID-19 pandemic.

Kinetics of Neutralizing Antibodies against Omicron Variant in Vietnamese Healthcare Workers after Primary Immunization with ChAdOx1-S and Booster Immunization with BNT162b2.

We studied the development and persistence of neutralizing antibodies against SARS-CoV-2 ancestral strain, and Delta and Omicron (BA.1 and BA.2) variants in Vietnamese healthcare workers (HCWs) up to 15 weeks after booster vaccination. We included 47 HCWs, including group 1 (G1, N = 21) and group 2 (G2; N = 26) without and with breakthrough Delta variant infection before booster immunization, respectively). The study participants had completed primary immunization with ChAdOx1-S and booster vaccination with BNT162b2. Neutralizing antibodies were measured using a surrogate virus neutralization assay. Of the 21 study participants in G1, neutralizing antibodies against ancestral strain, Delta variant, BA.1, and BA.2 were (almost) abolished at month 8 after the second dose, but all had detectable neutralizing antibodies to the study viruses at week 2 post booster dose. Of the 26 study participants in G2, neutralizing antibody levels to BA.1 and BA.2 were significantly higher than those to the corresponding viruses measured at week 2 post breakthrough infection and before the booster dose. At week 15 post booster vaccination, neutralizing antibodies to BA.1 and BA.2 dropped significantly, with more profound changes observed in those without breakthrough Delta variant infection. Booster vaccination enhanced neutralizing activities against ancestral strain and Delta variant compared with those induced by primary vaccination. These responses were maintained at high levels for at least 15 weeks. Our findings emphasize the importance of the first booster dose in producing cross-neutralizing antibodies against Omicron variant. A second booster to maintain long-term vaccine effectiveness against the currently circulating variants merits further research.

Absence of SARS-CoV-2 antibodies in pre-pandemic plasma from children and adults in Vietnam.

We tested pre-pandemic (2015--2019) plasma samples from 148 Vietnamese children and 100 Vietnamese adults at high risk of zoonotic infections for antibodies against SARS-CoV-2 nucleocapsid and spike proteins. None was positive. The data thus demonstrated no evidence of prior serological cross-reactivity with SARS-CoV-2 that might explain the low numbers of COVID-19 in Vietnam. No pre-existing cross-reactivity might explain Vietnam success of COVID-19 control.

The Role of Self-Compassion on Psychological Well-Being and Life Satisfaction of Vietnamese Undergraduate Students During the COVID-19 Pandemic: Hope as a Mediator

The simultaneous occurrence of the COVID-19 pandemic and the transition to adulthood have posed particular obstacles to university students’ mental health. However, it remains unclear whether hope promotes mental health in the relationship between self-compassion, psychological well-being, and life satisfaction. Therefore, this study investigated the role of hope as a mediator in the relationship between self-compassion, psychological well-being, and life satisfaction among Vietnamese undergraduate students in the context of the COVID-19 pandemic. Participants consisted of 484 students (aged 18–24) from several universities in Vietnam. To measure the four variables in the research model, we opted for the Self-Compassion Scale, the State Hope Scale, the World Health Organization 5-item Well-Being Index, and the Satisfaction With Life Scale. The results showed that (1) self-compassion was significantly positively correlated with psychological well-being, (2) self-compassion was not correlated with life satisfaction, (3) hope was a mediator of the relationship between self-compassion and psychological well-being, and (4) hope was a mediator of the relationship between self-compassion and life satisfaction. These findings suggest interventions on self-compassion to enhance hope and subsequently increase students’ mental health, which offers colleges, psychologists, and psychiatrists a guideline to cope with harmful psychological implications during the COVID-19 pandemic.

Proposed Detection Face Model by MobileNetV2 Using Asian Data Set

In 2019, the infectious coronavirus disease 2019 (COVID-19) was first reported in Wuhan, China. It has then become a public health problem in the world. This pandemic is having a heavy impact on the lives of people in our country. All countries are trying to control the spread of this disease. To solve the problem, each person needs to wear masks in a public place. Therefore, we propose a model capable of distinguishing between masked and nonmasked faces using a convolutional neural network (CNN) based on deep learning (DL)—MobileNetV2 in this paper. The model can detect people who are not wearing masks. It has an accuracy of up to 99.37%. The model will be applied in places such as schools, offices, and so on to monitor the wearing masks. [ FROM AUTHOR]

Stakeholders’ perspectives on the feasibility of adopting a Healthy Nail Salon Recognition Program in Philadelphia: A qualitative study (preprint)

ABSTRACT Background The California Healthy Nail Salon Recognition Program is a statewide initiative to incentivize nail salons to adopt safer practices such as use of safer nail products without certain harmful chemicals, installation of ventilation systems, proper personal protective equipment use, and staff training. This public policy intervention is in response to the call to protect nail care workers, mostly women of color, who bear disproportionate burden of chemical exposure at work. Because there is interest from the community to adopt similar program in the Greater Philadelphia region, we conducted this formative research to document stakeholders’ perspectives on the feasibility of adopting the Healthy Nail Salon Recognition Program in Philadelphia. Methods We conducted semi-structured interviews with a purposive sample of 31 stakeholders in Philadelphia in 2021. Using the Consolidated Framework for Implementation Science as our theoretical framework, we developed the interview guide and analyzed the data using qualitative research method to identify key facilitators and barriers. Results Key facilitating themes were perceived need and benefits of program to improve workers’ health and working conditions, and willingness of stakeholders to leverage their organizational resources. Barriers included perceived high cost and time commitment from salon owners and employees, lack of funding and implementation leaders at the city government, community members’ willingness to be visible and advocate for the program affected by the stigmas of being immigrant workers, fear of interacting with authorities, as well as the impact of COVID-19 pandemic. Our results suggest successful adoption of the Healthy Nail Salon Recognition Program in Philadelphia will require outreach within the community to raise awareness of the benefits of the program and close partnership with community-based organizations to facilitate mutual understanding between the authority and the ethnically diverse nail salon communities.

Immunogenicity of Oxford-AstraZeneca COVID-19 Vaccine in Vietnamese Health-Care Workers.

We studied the immunogenicity of the Oxford-AstraZeneca vaccine in health-care workers of a major infectious diseases hospital in Vietnam. We measured neutralizing antibodies before and 14 days after each dose, and at day 28 and month 3 after dose 1. A total of 554 workers (136 men and 418 women; age range, 22-71 years; median age, 36 years) participated with the study. Of the 144 participants selected for follow-up after dose 1, 104 and 94 gave blood for antibody measurement at weeks 6 and 8, and at month 3 after dose 1, respectively. The window time between the two doses was 6 weeks. At baseline, none had detectable neutralizing antibodies. After dose 1, the proportion of participants with detectable neutralizing antibodies increased from 27.3% (151 of 554) at day 14 to 78.0% (432 of 554) at day 28. Age correlated negatively with the development and the levels of neutralizing antibodies. However, at day 28, these differences were less profound, and women had a greater seroconversion rate and greater levels of neutralizing antibodies than men. After dose 2, these age and gender associations were not observable. In addition, the proportion of study participants with detectable neutralizing antibodies increased from 70.2% (73 of 104) before dose 2 (week 6, after dose 1) to 98.1% (102 of 104) 14 days later. At month 3, neutralizing antibodies decreased and 94.7% (89 of 94) of the study participants remained seropositive. The Oxford-AstraZeneca COVID-19 vaccine is immunogenic in Vietnamese health-care workers. These data are critical to informing the deployment of the COVID-19 vaccine in Vietnam and in Southeast Asia, where vaccination coverage remains inadequate.

An observational study of breakthrough SARS-CoV-2 Delta variant infections among vaccinated healthcare workers in Vietnam.

BACKGROUND: Data on breakthrough SARS-CoV-2 Delta variant infections in vaccinated individuals are limited. METHODS: We studied breakthrough infections among Oxford-AstraZeneca vaccinated healthcare workers in an infectious diseases hospital in Vietnam. We collected demographic and clinical data alongside serial PCR testing, measurement of SARS-CoV-2 antibodies, and viral whole-genome sequencing. FINDINGS: Between 11th-25th June 2021 (7-8 weeks after the second dose), 69 staff tested positive for SARS-CoV-2. 62 participated in the study. Most were asymptomatic or mildly symptomatic and all recovered. Twenty-two complete-genome sequences were obtained; all were Delta variant and were phylogenetically distinct from contemporary viruses obtained from the community or from hospital patients admitted prior to the outbreak. Viral loads inferred from Ct values were 251 times higher than in cases infected with the original strain in March/April 2020. Median time from diagnosis to negative PCR was 21 days (range 8-33). Neutralizing antibodies (expressed as percentage of inhibition) measured after the second vaccine dose, or at diagnosis, were lower in cases than in uninfected, fully vaccinated controls (median (IQR): 69.4 (50.7-89.1) vs. 91.3 (79.6-94.9), p=0.005 and 59.4 (32.5-73.1) vs. 91.1 (77.3-94.2), p=0.002). There was no correlation between vaccine-induced neutralizing antibody levels and peak viral loads or the development of symptoms. INTERPRETATION: Breakthrough Delta variant infections following Oxford-AstraZeneca vaccination may cause asymptomatic or mild disease, but are associated with high viral loads, prolonged PCR positivity and low levels of vaccine-induced neutralizing antibodies. Epidemiological and sequence data suggested ongoing transmission had occurred between fully vaccinated individuals. FUNDING: Wellcome and NIH/NIAID.

Long-Term Humoral Immune Response in Persons with Asymptomatic or Mild SARS-CoV-2 Infection, Vietnam.

Antibody response against nucleocapsid and spike proteins of SARS-CoV-2 in 11 persons with mild or asymptomatic infection rapidly increased after infection. At weeks 18-30 after diagnosis, all remained seropositive but spike protein-targeting antibody titers declined. These data may be useful for vaccine development.

The Application of Sample Pooling for Mass Screening of SARS-CoV-2 in an Outbreak of COVID-19 in Vietnam.

We sampled nasal-pharyngeal throat swabs from 96,123 asymptomatic individuals at risk of SARS-CoV-2 infection, and generated 22,290 pools at collection, each containing samples from two to seven individuals. We detected SARS-CoV-2 in 24 pools, and confirmed the infection in 32 individuals after resampling and testing of 104 samples from positive pools. We completed the testing within 14 days. We would have required 64 days to complete the screening for the same number of individuals if we had based our testing strategy on individual testing. There was no difference in cycle threshold (Ct) values of pooled and individual samples. Thus, compared with individual sample testing, our approach did not compromise PCR sensitivity, but saved 77% of the resources. The present strategy might be applicable in settings, where there are shortages of reagents and the disease prevalence is low, but the demand for testing is high.

The Natural History and Transmission Potential of Asymptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Infection.

BACKGROUND: Little is known about the natural history of asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: We conducted a prospective study at a quarantine center for coronavirus disease 2019 in Ho Chi Minh City, Vietnam. We enrolled quarantined people with reverse-transcription polymerase chain reaction (RT-PCR)-confirmed SARS-CoV-2 infection, collecting clinical data, travel and contact history, and saliva at enrollment and daily nasopharyngeal/throat swabs (NTSs) for RT-PCR testing. We compared the natural history and transmission potential of asymptomatic and symptomatic individuals. RESULTS: Between 10 March and 4 April 2020, 14 000 quarantined people were tested for SARS-CoV-2; 49 were positive. Of these, 30 participated in the study: 13 (43%) never had symptoms and 17 (57%) were symptomatic. Seventeen (57%) participants imported cases. Compared with symptomatic individuals, asymptomatic people were less likely to have detectable SARS-CoV-2 in NTS collected at enrollment (8/13 [62%] vs 17/17 [100%]; P = .02). SARS-CoV-2 RNA was detected in 20 of 27 (74%) available saliva samples (7 of 11 [64%] in the asymptomatic group and 13 of 16 [81%] in the symptomatic group; P = .56). Analysis of RT-PCR positivity probability showed that asymptomatic participants had faster viral clearance than symptomatic participants (P < .001 for difference over the first 19 days). This difference was most pronounced during the first week of follow-up. Two of the asymptomatic individuals appeared to transmit SARS-CoV-2 to 4 contacts. CONCLUSIONS: Asymptomatic SARS-CoV-2 infection is common and can be detected by analysis of saliva or NTSs. The NTS viral loads fall faster in asymptomatic individuals, but these individuals appear able to transmit the virus to others.

Suspected Heparin-Induced Thrombocytopenia in a COVID-19 Patient on Extracorporeal Membrane Oxygenation Support: A Case Report. (preprint)

Background: Extracorporeal membrane oxygenation (ECMO) support can be life-saving in critically ill COVID-19 patients. However, there are many complications associated with this procedure, including Heparin-induced thrombocytopenia (HIT.) Despite its rarity in ECMO cases, HIT can lead to devastating consequences and is difficult to manage. Case presentation In this report, we present a case of a COVID-19 patient on ECMO support who was diagnosed with HIT and required intensive treatment. Initially, HIT was only suspected due to newly-developed thrombocytopenia and oxygenator dysfunction, with thrombi observed later. Regarding his treatment, since there was no recommended replacement to heparin available to us at the time of diagnosis, we decided to use rivaroxaban temporarily. No adverse events were recorded during that period. The patient was able to make a full recovery. Conclusion: HIT may jeopardize patient’s care during ECMO. As COVID-19 may bring about a surge in the number of patients requiring ECMO support, we need consented guidance to optimize treatment in this specific situation.