Publications by authors named "Yun Yan Mah"
Inflammasome is linked to many inflammatory diseases, including COVID-19 and autoimmune liver diseases. While severe COVID-19 was reported to exacerbate liver failure, we report a fatal acute-on-chronic liver failure (ACLF) in a stable primary biliary cholangitis-autoimmune hepatitis overlap syndrome patient triggered by a mild COVID-19 infection. Postmortem liver biopsy showed sparse SARS-CoV-2-infected macrophages with extensive ASC (apoptosis-associated speck-like protein containing a CARD) speck-positive hepatocytes, correlating with elevated circulating ASC specks and inflammatory cytokines, and depleted blood monocyte subsets, indicating widespread liver inflammasome activation.
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- 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.
Article Synopsis
- A study found that giving Sinovac-CoronaVac boosters to 12-17-year-olds who had a moderate or severe reaction to Pfizer-BNT162b2 is safe, with no serious side effects reported.
- Adolescents who received one dose of Pfizer followed by two doses of Sinovac-CoronaVac had similar antibody levels to those who got two doses of Pfizer followed by one dose of Sinovac-CoronaVac.
- The study also showed that the Pfizer-Sinovac combination boosted T-cell responses, particularly against the Spike protein, with significant levels lasting up to 150 days after vaccination.
Despite SARS-CoV-2 vaccines eliciting systemic neutralising antibodies (nAbs), breakthrough infections still regularly occur. Infection helps to generate mucosal immunity, possibly reducing disease transmission. Monitoring mucosal nAbs is predominantly restricted to lab-based assays, which have limited application to the public.
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.
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- 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.