A5029139785- SARS-CoV-2 and COVID-19 Research
- COVID-19 Clinical Research Studies
- Viral Infections and Vectors
- SARS-CoV-2 detection and testing
- Animal Virus Infections Studies
- COVID-19 epidemiological studies
- Mosquito-borne diseases and control
- Malaria Research and Control
- Long-Term Effects of COVID-19
- interferon and immune responses
- Rabies epidemiology and control
- Viral gastroenteritis research and epidemiology
- Inflammasome and immune disorders
- Cytomegalovirus and herpesvirus research
- COVID-19 and Mental Health
- vaccines and immunoinformatics approaches
- Virology and Viral Diseases
- Viral Infections and Outbreaks Research
- Viral Infections and Immunology Research
- Computational Drug Discovery Methods
- Developmental Biology and Gene Regulation
- Infection Control and Ventilation
- Research on Leishmaniasis Studies
- Vaccine Coverage and Hesitancy
- Bat Biology and Ecology Studies
Duke-NUS Medical School
2018-2024
National University of Singapore
1990-2024
Merck (Singapore)
2023
National Centre for Infectious Diseases
2020
Nanjing University of Chinese Medicine
2020
Singapore Immunology Network
2014-2016
Agency for Science, Technology and Research
2014-2016
Temasek Life Sciences Laboratory
2005
Institute of Molecular and Cell Biology
1991
Royal North Shore Hospital
1968
A robust serological test to detect neutralizing antibodies SARS-CoV-2 is urgently needed determine not only the infection rate, herd immunity and predicted humoral protection, but also vaccine efficacy during clinical trials after large-scale vaccination. The current gold standard conventional virus neutralization requiring live pathogen a biosafety level 3 laboratory. Here, we report surrogate that detects total immunodominant targeting viral spike (S) protein receptor-binding domain in an...
Virus-specific humoral and cellular immunity act synergistically to protect the host from viral infection. We interrogate dynamic changes of virological immunological parameters in 12 patients with symptomatic acute SARS-CoV-2 infection disease onset convalescence or death. quantify RNA respiratory tract parallel antibodies circulating T cells specific for various structural (nucleoprotein [NP], membrane [M], ORF3a, spike) non-structural (ORF7/8, NSP7, NSP13) proteins. Although rapid...
The mechanism of action artemisinin and its derivatives, the most potent anti-malarial drugs, is not completely understood. Here we present an unbiased chemical proteomics analysis to directly explore this in Plasmodium falciparum. We use alkyne-tagged analogue coupled with biotin identify 124 covalent binding protein targets, many which are involved essential biological processes parasite. Such a broad targeting spectrum disrupts biochemical landscape parasite causes death. Furthermore,...
Among the many questions unanswered for COVID-19 pandemic are origin of SARS-CoV-2 and potential role intermediate animal host(s) in early animal-to-human transmission. The discovery RaTG13 bat coronavirus China suggested a high probability origin. Here we report molecular serological evidence related coronaviruses (SC2r-CoVs) actively circulating bats Southeast Asia. Whole genome sequences were obtained from five independent (Rhinolophus acuminatus) Thai cave yielding single isolate (named...
Studies have found different waning rates of neutralising antibodies compared with binding against SARS-CoV-2. The impact antibody rate at the individual patient level on longevity immunity remains unknown. We aimed to investigate peak levels and dynamics IgG avidity maturation over time, correlate this clinical parameters, cytokines, T-cell responses.We did a longitudinal study patients who had recovered from COVID-19 up day 180 post-symptom onset by monitoring changes in using previously...
The efficacy of virus-specific T cells in clearing pathogens involves a fine balance between antiviral and inflammatory features. SARS-CoV-2–specific individuals who clear SARS-CoV-2 without symptoms could reveal nonpathological yet protective characteristics. We longitudinally studied cohort asymptomatic (n = 85) symptomatic 75) COVID-19 patients after seroconversion. quantified reactive to structural proteins (M, NP, Spike) using ELISpot cytokine secretion whole blood. Frequencies were...
During the SARS epidemic in 2003/2004, a number of deletions were observed ORF8 SARS-CoV, and eventually deletion variants became predominant, leading to hypothesis that was an evolutionary hot spot for adaptation SARS-CoV humans. However, due successful control epidemic, importance these epidemiological fitness humans could not be established. The emergence multiple SARS-CoV-2 strains with deletions, combined evidence robust immune response ORF8, suggests lack may assist host evasion. In...
Highly effective vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developed but variants of concerns are worrisome, especially B.1.617.2 (Delta) which has rapidly spread across the world. We aim to study if vaccination alters virological and serological kinetics in breakthrough infections.
Key knowledge gaps remain in the understanding of viral dynamics and immune response Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection.We evaluated these characteristics established their association with clinical severity a prospective observational cohort study 100 patients PCR-confirmed SARS-CoV-2 infection (mean age, 46 years; 56% male; 38% comorbidities). samples (n = 74) were collected for culture, serum measurement IgM/IgG levels 30), plasma inflammatory cytokines...
Objectives Highly effective vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developed but variants of concerns (VOCs) with mutations in the spike protein are worrisome, especially B.1.617.2 (Delta) which has rapidly spread across world. We aim to study if vaccination alters virological and serological kinetics breakthrough infections. Methods conducted a multi-centre retrospective cohort patients Singapore who had received licensed mRNA vaccine...
Defining the correlates of protection necessary to manage COVID-19 pandemic requires analysis both antibody and T cell parameters, but complexity traditional tests limits virus-specific measurements. We tested sensitivity performance a simple rapid SARS-CoV-2 spike protein–specific test based on stimulation whole blood with peptides covering protein, followed by cytokine (IFN-γ, IL-2) measurement in different cohorts including BNT162b2-vaccinated individuals (n = 112), convalescent...
In response to the coronavirus disease 2019 (COVID-19) outbreak, caused by SARS-CoV-2, multiple diagnostic tests are required for acute diagnosis, contact tracing, monitoring asymptomatic infection rates and assessing herd immunity. While PCR remains frontline test of choice in setting, serological urgently needed. Unlike which highly specific, cross-reactivity is a major challenge COVID-19 antibody considering there six other coronaviruses known infect humans. SARS-CoV genetically related...
Despite initial findings indicating that SARS-CoV and SARS-CoV-2 are genetically related belonging to the same virus species two viruses used entry receptor, angiotensin-converting enzyme 2 (ACE2), our data demonstrated there is no detectable cross-neutralization by SARS patient sera against SARS-CoV-2. We also found significant levels of neutralizing antibodies in recovered patients 9–17 years after infection. These will be use guiding development serologic tests, formulating convalescent...
Several studies have shown that neutralising antibody level is a good biomarker for the correlate of protection against SARS-CoV-2 infection.1Bergwerk M Gonen T Lustig Y et al.COVID-19 breakthrough infections in vaccinated health care workers.N Engl J Med. 2021; 385: 1474-1484Crossref PubMed Scopus (836) Google Scholar, 2Khoury DS Cromer D Reynaldi A al.Neutralizing levels are highly predictive immune from symptomatic infection.Nat 27: 1205-1211Crossref (2073) 3Feng S Phillips DJ White...
Abstract Understanding the impact of age on vaccinations is essential for design and delivery vaccines against SARS-CoV-2. Here, we present findings from a comprehensive analysis multiple compartments memory immune response in 312 individuals vaccinated with BNT162b2 SARS-CoV-2 mRNA vaccine. Two vaccine doses induce high antibody T cell responses most individuals. However, recognition Spike protein Delta Omicron variants less efficient than that ancestral Wuhan strain. Age-stratified...
There is limited information on the functional neutralizing capabilities of breastmilk SARS-CoV-2-specific antibodies and potential adulteration with vaccine mRNA after SARS-CoV-2 vaccination. We conducted a prospective cohort study lactating healthcare workers who received BNT162b2 their infants. The presence antibodies, antibody isotypes (IgG, IgA, IgM) intact in serum was evaluated at multiple time points using surrogate assay, ELISA, PCR, over 6 week period two-dose vaccination given 21...
Multiple Omicron sub-lineages have emerged, with XBB and XBB.1.5 subvariants becoming the dominant variants globally at time of this study. The key feature new is their ability to escape humoral immunity despite fact that there are limited genetic changes from preceding variants. This raises question whether should be regarded as a separate serotype viruses serologically clustered ancestral severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Here, we present...
Abstract At this critical moment of the international response to COVID-19 outbreak, there is an urgent need for a robust serological test detect neutralizing antibodies SARS-CoV-2. Such not only important contact tracing, but determining infection rate, herd immunity and predicted humoral protection. The current gold standard virus neuralization (VNT) requiring live biosafety level 3 (BSL3) laboratory. On other hand, ELISA- or lateral flow-based assays are detection binding antibodies,...