Publications by authors named "Hor P"

Background: BBV152 (Covaxin™) is a whole-virion inactivated SARS-CoV-2 vaccine mixed with an immune adjuvant. We aimed to compare immune responses after booster vaccination with heterologous BBV152 versus homologous mRNA vaccine.

Methods: We conducted a randomized, participant-blinded, controlled trial.

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Objectives: The emergence of new SARS-CoV-2 variants has led to the development of Omicron-targeting bivalent mRNA vaccines. It is crucial to understand how bivalent vaccines may improve antibody responses against new variants.

Methods: A total of 107 participants, who had three COVID-19 WT mRNA vaccine doses, were recruited, and given either a monovalent (WT) or a bivalent mRNA vaccination (Pfizer/BioNTech Bivalent (WT and BA.

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Article Synopsis
  • SARS-CoV-2 variants and reduced vaccine immunity have led to increased cases of breakthrough infections, highlighting the need to understand vaccine protection mechanisms.
  • Researchers analyzed mRNA vaccinated individuals in Singapore during the Omicron surge to compare immune responses.
  • Findings suggest those who stayed uninfected developed a stronger variant-specific IgA response after booster shots, indicating IgA may play an important role in protecting against Omicron.
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Identification of the risk factors and the high-risk groups which are most vulnerable is critical in COVID-19 disease management at a population level. Evaluating the efficacy of vaccination against infections is necessary to determine booster vaccination strategies for better protection in high-risk groups. In this study, we recruited 158 mRNA-vaccinated individuals during the Delta wave of SARS-CoV-2 infections in Singapore and examined the antibody profiles of infected individuals.

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Vaccine immunogenicity in transplant recipients can be impacted by the immunosuppressive (IS) regimens they receive. While BNT162b2 vaccination has been shown to induce an immune response in liver transplant recipients (LTRs), it remains unclear how different IS regimens may affect vaccine immunogenicity after a third BNT162b2 dose in LTRs, which is especially important given the emergence of the Omicron sublineages of SARS-CoV-2. A total of 95 LTRs receiving single and multiple IS regimens were recruited and offered three doses of BNT162b2 during the study period.

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Introduction: COVID-19 has a wide disease spectrum ranging from asymptomatic to severe. While humoral immune responses are critical in preventing infection, the immune mechanisms leading to severe disease, and the identification of biomarkers of disease progression and/or resolution of the infection remains to be determined.

Methods: Plasma samples were obtained from infections during the initial wave of ancestral wildtype SARS-CoV-2 and from vaccine breakthrough infections during the wave of Delta variant, up to six months post infection.

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The emergence of new SARS-CoV-2 variants, such as the more transmissible Delta and Omicron variants, has raised concerns on efficacy of the COVID-19 vaccines. Here, we examined the waning of antibody responses against different variants following primary and booster vaccination. We found that antibody responses against variants were low following primary vaccination.

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Waning antibody levels against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the emergence of variants of concern highlight the need for booster vaccinations. This is particularly important for the elderly population, who are at a higher risk of developing severe coronavirus disease 2019 (COVID-19) disease. While studies have shown increased antibody responses following booster vaccination, understanding the changes in T and B cell compartments induced by a third vaccine dose remains limited.

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Objective: Despite the high vaccine efficacy of mRNA COVID-19 vaccines, there are individuals who developed excessive reactogenic and/or allergic responses after the first mRNA dose and were considered ineligible for further mRNA doses. CoronaVac, an inactivated SARS-CoV-2 vaccine, is recommended in Singapore as an alternative.

Methods: Individuals, ineligible for further mRNA vaccines (BNT162b2 or mRNA-1273) because of excessive reactive responses to prime mRNA vaccination, were recruited and offered two doses of CoronaVac as booster vaccination 38-224 days post their mRNA vaccine dose.

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Article Synopsis
  • Understanding age influences vaccine response is key for effective SARS-CoV-2 vaccine design.
  • In a study of 312 people vaccinated with the BNT162b2 vaccine, most showed strong antibody and T cell responses, although antibody effectiveness decreased against Delta and Omicron variants.
  • Older adults (≥60 years) had lower antibody responses but developed longer-lasting immunity over six months, and a third vaccine dose significantly improved their antibody responses against all variants.
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The present study has been aimed at evaluating the antiobesity, antihyperglycemic, and antidepressive potentials of starter-based rice fermented foods. High-throughput NGS technology has revealed a number of bacterial genera in the prepared fermented rice, such as (29.44%), (16.

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Treatment of cancer with allogeneic natural killer (NK) cell therapies has seen rapid development, especially use against hematologic malignancies. Clinical trials of NK cell-based adoptive transfer to treat relapsed or refractory malignancies have used peripheral blood, umbilical cord blood and pluripotent stem cell-derived NK cells, with each approach undergoing continued clinical development. Improving the potency of these therapies relies on genetic modifications to improve tumor targeting and to enhance expansion and persistence of the NK cells.

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The popularity of traditional fermented food products is based on their healthiness. The addition of a starter brings consistent, desirable, and predictable food changes with improved nutritive, functional, and sensory qualities. The addition of a mixture of plant residues as a starter or source of microbes is an age-old practice to prepare traditional fermented food and beverages, and most of the reported data on traditional foods were based on the analysis of the final product.

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Serial passaging of the human fungal pathogen in the gastrointestinal tract of antibiotics-treated mice selects for virulence-attenuated strains. These gut-evolved strains protect the host from infection by a wide range of pathogens trained immunity. Here, we further investigated the molecular and cellular mechanisms underlying this innate immune memory.

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Probiotic bacteria are now becoming an effective natural medicine for alleviating many non-communicable lifestyle-related diseases. The present study was conducted to evaluate the antioxidant and antitoxicant properties of a foodborne probiotic sp. MKK4 and its rice fermented beverage.

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Malaria-associated acute respiratory distress syndrome (MA-ARDS) is a severe complication of malaria that occurs despite effective antimalarial treatment. Currently, noninvasive imaging procedures such as chest X-rays are used to assess edema in established MA-ARDS, but earlier detection methods are needed to reduce morbidity and mortality. The early stages of MA-ARDS are characterized by the infiltration of leukocytes, in particular monocytes/macrophages; thus, monitoring of immune infiltrates may provide a useful indicator of early pathology.

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The human fetal immune system begins to develop early during gestation; however, factors responsible for fetal immune-priming remain elusive. We explored potential exposure to microbial agents in utero and their contribution toward activation of memory T cells in fetal tissues. We profiled microbes across fetal organs using 16S rRNA gene sequencing and detected low but consistent microbial signal in fetal gut, skin, placenta, and lungs in the 2 trimester of gestation.

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Purpose: To develop a dual-echo phase-contrast (DEPC) MRI approach with which each echo is acquired by using a different velocity sensitivity within one repetition time (TR) and demonstrate the feasibility of this approach to measure transmitral blood flow and myocardial tissue ( ) velocities.

Materials And Methods: The flow across tubes of known diameter was measured by using the proposed DEPC method and compared with flowmeter measurements and theoretic predictions. Then, with both the DEPC MRI sequence and the conventional single-echo phase-contrast (SEPC) MRI sequence, , and were measured in six healthy volunteers (mean age, 49 years ± 13 [standard deviation]) and eight patients (mean age, 54 years ± 15) being evaluated for cardiac disease.

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Early detection of infection is crucial to limit the spread of coronavirus disease 2019 (COVID-19). Here we develop a flow cytometry-based assay to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein antibodies in individuals with COVID-19. The assay detects specific immunoglobulin M (IgM), IgA, and IgG in individuals with COVID-19 and also acquisition of all IgG subclasses, with IgG1 being the most dominant.

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Article Synopsis
  • Khambir is a traditional leavened bread from the Western Himalaya, made using either yeast or buttermilk, and is packed with carbohydrates, protein, dietary fiber, and essential nutrients with low fat and gluten levels.
  • The fermentation process enhances its digestibility and results in a slow glucose release, indicating a favorable glycemic index and nutritious starch content.
  • Research shows that khambir has protective properties against cold-induced gastric ulcers, showcasing its potential health benefits, particularly for those experiencing acute mountain sickness.
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