A5035565664- SARS-CoV-2 and COVID-19 Research
- COVID-19 Clinical Research Studies
- SARS-CoV-2 detection and testing
- Viral gastroenteritis research and epidemiology
- Malaria Research and Control
- Animal Virus Infections Studies
- Mosquito-borne diseases and control
- Salmonella and Campylobacter epidemiology
- Long-Term Effects of COVID-19
- Escherichia coli research studies
- vaccines and immunoinformatics approaches
- Bacteriophages and microbial interactions
- Bacterial Infections and Vaccines
- Vaccine Coverage and Hesitancy
- Immunotherapy and Immune Responses
- Invertebrate Immune Response Mechanisms
- CAR-T cell therapy research
- Bacillus and Francisella bacterial research
- Poxvirus research and outbreaks
- COVID-19 and Mental Health
- Parasites and Host Interactions
- Diabetes and associated disorders
- Hepatitis Viruses Studies and Epidemiology
- Infectious Encephalopathies and Encephalitis
- Immune responses and vaccinations
Agency for Science, Technology and Research
2015-2025
Singapore Immunology Network
2014-2022
A*STAR Graduate Academy
2021-2022
Toscana Life Sciences
2012-2021
Star Technology and Research (United States)
2021
Technology Centre Prague
2020
University of Cambridge
2011-2016
Wellcome Sanger Institute
2015
Novartis (Italy)
2012
Heterochromatin plays a central role in the process of immune evasion, pathogenesis, and transmission malaria parasite Plasmodium falciparum during blood stage infection. Here, we use ChIP sequencing to demonstrate that sporozoites from mosquito salivary glands expand heterochromatin at subtelomeric regions silence blood-stage-specific genes. Our data also revealed enrichment is predictive transcription status clonally variant genes members mediate cytoadhesion parasites. A specific member...
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...
ABSTRACT Mathematical models of viral dynamics are crucial in understanding infection trajectories. However, severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) load data often includes limited sparse observations with significant heterogeneity. This study aims to: (1) understand the impact patient characteristics shaping temporal trajectory and (2) establish a collection protocol (DCP) to reliably reconstruct individual We collected longitudinal for SARS‐CoV‐2 Delta Omicron...
Early detection of infection is crucial to limit the spread coronavirus disease 2019 (COVID-19). Here we develop a flow cytometry-based assay detect severe acute respiratory syndrome 2 (SARS-CoV-2) spike (S) protein antibodies in individuals with COVID-19. The detects specific immunoglobulin M (IgM), IgA, and IgG COVID-19 also acquisition all subclasses, IgG1 being most dominant. antibody response significantly higher at later stage infection. Furthermore, asymptomatic IgM, IgG, dominant...
The immune responses and mechanisms limiting symptom progression in asymptomatic cases of SARS-CoV-2 infection remain unclear. We comprehensively characterized transcriptomic profiles, cytokine responses, neutralization capacity antibodies, cellular phenotypes patients with acute to identify potential protective mechanisms. Compared symptomatic patients, had higher counts mature neutrophils lower proportion CD169+ expressing monocytes the peripheral blood. Systemic levels pro-inflammatory...
The emergence of new SARS-CoV-2 variants, such as the more transmissible Delta and Omicron has raised concerns on efficacy COVID-19 vaccines. Here, we examined waning antibody responses against different variants following primary booster vaccination. We found that were low response was almost non-existent. Efficient boosting all including Omicron, observed a third dose. tested significantly higher at one month vaccination, compared with two months for individuals, responders identified...
Summary Several classes and multiple subclasses of immunoglobulins are produced towards protein polysaccharide antigens in response to Salmonella infection play a key role protection against systemic disease. The targeting Fc receptors (FcR) on phagocytes is step the antibody‐mediated antibacterial functions host cells. We wished compare relative efficiency different human IgG subclasses, which targeted enterica OmpA surface modulating interaction bacteria with phagocytes. To this end, we...
ABSTRACT Nontyphoidal Salmonella (NTS), particularly enterica serovars Typhimurium and Enteritidis, is responsible for a major global burden of invasive disease with high associated case-fatality rates. We recently reported the development candidate O-antigen–CRM 197 glycoconjugate vaccine against S. Typhimurium. Here, using panel mouse monoclonal antibodies generated by vaccine, we examined relative efficiency different antibody isotypes specific O:4 antigen S . to effect in vitro vivo...
The development of an effective malaria vaccine has remained elusive even until today. This is because our incomplete understanding the immune mechanisms that confer and/or correlate with protection. Human volunteers have been protected experimentally from a subsequent challenge by immunization Plasmodium falciparum sporozoites under drug cover. Here, we demonstrate sera individuals contain neutralizing antibodies against pre-erythrocytic stage. To identify antigen(s) recognized these...
ABSTRACT Antibodies acquired after vaccination or natural infection with Gram-negative bacteria, such as invasive Salmonella enterica serovar Typhimurium, can protect against disease. Immunization naturally shed outer membrane vesicles from bacteria is being studied for its potential to many infections, since antigens within maintain their conformation and orientation. Shedding be enhanced through genetic modification, the resulting particles, generalized modules (GMMA), not only offer...
SARS-CoV-2 was first detected in late December 2019, however, the few months that followed, resultant COVID-19 disease has developed into a devastating pandemic around world [[1]https://covid19.who.int/.Google Scholar]. This led to race produce safe and efficacious vaccine record time. In less than year, BNT162b2, an mRNA-based by BioNTech-Pfizer [[2]Polack FP Thomas SJ Kitchin N et al.Safety efficacy of BNT162b2 mRNA Covid-19 vaccine.N Engl J Med. 2020; 383: 2603-2615Crossref PubMed Scopus...
Abstract Introduction In August 2024, the World Health Organization (WHO) declared a public health emergency due to rapid spread of mpox in African and beyond. International travel controls (ITCs), such as screening viral testing, could help avoid/delay global monkeypox virus (MPXV), fostering preparedness response efforts. However, it is not clear whether tests at immigration are sufficient avoid importation MPXV which samples should be used on tests. Methods We conducted simulation study...
Background/Objectives: mRNA vaccines have demonstrated strong immunogenicity and efficacy against SARS-CoV-2. However, the extent of antibody cross-reactivity human seasonal coronaviruses, such as NL63, remains unclear. Furthermore, it is unknown whether pre-existing responses NL63 might influence outcome SARS-CoV-2 vaccination. Methods: We used a flow cytometry-based serological assay an in vitro neutralization to analyze sera from mRNA-vaccinated mice plasma samples vaccinated cohort....
One of the key public health strategies in coronavirus 2019 disease (COVID-19) management is early detection infected individuals to limit transmission. As a result, serological assays have been developed complement PCR-based assays. Here, we report development flow cytometry-based assay detect antibodies against full-length SARS-CoV-2 spike protein (S protein) patients with COVID-19. The time-efficient and sensitive, being able capture wider repertoire S protein. For complete details on use...
Abstract Objectives The emergence of a SARS‐CoV‐2 variant with point mutation in the spike (S) protein, D614G, has taken precedence over original Wuhan isolate by May 2020. With an increased infection and transmission rate, it is imperative to determine whether antibodies induced against D614 may cross‐neutralise G614 variant. Methods Antibody profiling S protein flow cytometry assessment neutralising antibody titres using pseudotyped lentiviruses expressing either or tagged luciferase...
Nontyphoidal isolates of Salmonella (NTS), particularly Typhimurium, are a major cause invasive bacteremia in Africa. Despite this, no vaccine against NTS is currently available for use humans. If to be developed timely manner, there need develop assays assess its vivo efficacy. Assessment potential efficacy candidate vaccines preclinical models important proof-of-concept and reduces attrition clinical trials. Serum bactericidal (SBA) often used the functional activity vaccine-induced...
Nontyphoidal strains of Salmonella are a leading cause death among HIV-infected Africans. Antibody-induced complement-mediated killing protects healthy Africans against Salmonella, but increased levels anti-lipopolysaccharide (LPS) antibodies in some African adults block this killing. The objective was to understand how these high anti-LPS interfere with the Salmonella.Sera and affinity-purified from that failed kill invasive S. Typhimurium D23580 were compared sera HIV-uninfected subjects...
The rapid spreading of SARS-CoV-2 variants B.1.1.7 originated from the United Kingdom and B.1.351 South Africa has contributed to second wave COVID-19 cases in respective countries also around world. In this study, we employed advanced biochemical virological methodologies evaluate impact Spike mutations these strains on degree protection afforded by humoral immune responses following natural infection ancestral strain during early stages outbreak. We found that antibody-mediated...