Publications by authors named "Aileen Ying-Yan Yeoh"
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.
Article Synopsis
- Multiple Omicron sub-lineages, particularly XBB and XBB.1.5, have become the global dominant variants, showcasing their ability to evade immunity despite minor genetic changes from previous variants.
- Researchers conducted a pseudovirus neutralization test with convalescent sera from individuals who recovered from SARS-CoV infections, including various Omicron subvariants.
- The findings showed no significant cross-neutralization among the different strains, suggesting that current SARS-related coronaviruses should be classified into three distinct serotypes.
Current coronavirus disease 2019 vaccines face limitations including waning immunity, immune escape by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, limited cellular response, and poor mucosal immunity. We engineered a Clec9A-receptor binding domain (RBD) antibody construct that delivers the SARS-CoV-2 RBD to conventional type 1 dendritic cells. Compared with non-targeting approaches, single dose immunization in mice with Clec9A-RBD induced far higher RBD-specific antibody titers that were sustained for up to 21 months after vaccination.
View Article and Find Full Text PDFThere is little information on BNT162b2 vaccine-induced variant-specific immunogenicity, safety data and dynamics of breakthrough infections in pediatric populations. We addressed these questions using a prospective two dose BNT162b2 (10 mcg) vaccination cohort study of healthy children 5-11 years in Singapore. Follow up included blood samples at scheduled visits, daily vaccination symptom diary and confirmation of SARS-CoV-2 infection.
View Article and Find Full Text PDFThe emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern such as Omicron hampered efforts in controlling the ongoing coronavirus disease 2019 pandemic due to their ability to escape neutralizing antibodies induced by vaccination or prior infection, highlighting the need to develop broad-spectrum vaccines and therapeutics. Most human monoclonal antibodies (mAbs) reported to date have not demonstrated true pan-sarbecovirus neutralizing breadth especially against animal sarbecoviruses. Here, we report the isolation and characterization of highly potent mAbs targeting the receptor binding domain (RBD) of huACE2-dependent sarbecovirus from a SARS-CoV survivor vaccinated with BNT162b2.
View Article and Find Full Text PDFVaccines that are broadly cross-protective against current and future SARS-CoV-2 variants of concern (VoC) or across the sarbecoviruses subgenus remain a priority for public health. Virus neutralization is the best available correlate of protection. To define the magnitude and breadth of cross-neutralization in individuals with different exposure to SARS-CoV-2 infection and vaccination, we here use a multiplex surrogate neutralization assay based on virus spike receptor binding domains of multiple SARS-CoV-2 VoC, as well as related bat and pangolin viruses.
View Article and Find Full Text PDFArticle Synopsis
- The Omicron variant of SARS-CoV-2, detected in November 2021, has numerous mutations in its spike protein, allowing it to significantly evade neutralizing antibodies from previous infections or vaccinations.
- A study used a high-resolution 16-plex assay to test neutralization abilities against various SARS-CoV-2 variants and found that Omicron and other variants showed a marked reduction in neutralization compared to the original virus.
- Notably, genetically distant sarbecoviruses from bats and pangolins displayed less ability to escape neutralization compared to Omicron, highlighting the impact of human immune responses on the virus's evolution.