Using multiple assays for detecting antibodies to the SARS-CoV-2 Spike (S) glycoprotein, a recent pre-peer reviewed paper in bioRxiv shows “pre-existing immunity in uninfected and unexposed humans to the new coronavirus.” The authors were able to detect Spike-reactive IgG in SARS-CoV-2-uninfected individuals with recent other Coronavirus (HCoV) infections using a sensitive flow cytometry...
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Is COVID-19 an endothelial disease?
A recent report in The Lancet cites three case studies showing that cardiovascular complications, in addition to respiratory disease, may be emerging as a “key threat in coronavirus disease 2019 (COVID-19)”. The authors present cases that demonstrate endothelial cell involvement across vascular beds of different organs in COVID-19. They show the “presence of viral elements within endothelial cells and an accumulation of inflammatory cells
A recombinant adenovirus type-5 vectored COVID-19 vaccine appears safe and immunogenic in a first-in-human trial.
A replication defective Ad5 vectored vaccine expressing the spike glycoprotein of SARS-CoV-2 based on the full-length spike gene from the Wuhan-Hu-1 strain was given to three groups of volunteers at different doses (thirty six volunteers in each). The most common injection site adverse reaction was pain, reported in 58 (54%) vaccine recipients...
SARS-CoV-2 monkey model shows protection from re-infection.
With an impending second wave of SARS-CoV-2 infections predicted, one important question is whether a person infected once can develop enough durable protective immunity to prevent re-infection when exposed again. In a recent edition of Science, a rhesus macaque model of SARS-CoV-2 infection was developed, where “high viral loads in the upper and lower respiratory tract, humoral and cellular immune responses...
An exuberant inflammatory host response to SARS-CoV-2 leads to COVID-19.
A recent study in Cell focused on defining the host response to SARS-CoV-2 and other human respiratory viruses in cell lines, primary cell cultures, ferrets, and COVID-19 patients. The authors show a distinct transcriptional footprint exists with SARS-CoV-2 infection when compared with other coronaviruses and common respiratory viruses such as IAV, HPIV3, and RSV. The response to SARS-CoV-2 was defined...
IUIS Webinar: Role of cellular responses in COVID-19
IUIS webinar by Sharon Lewin and Katherine Kedzierska show how immunity to SARS-CoV2 has demonstrated the breadth of concomitant immune responses associated with recovery in patients with mild to moderate COVID-19 requiring hospitalisation. Their study indicates that robust multi-factorial immune responses can be elicited towards the newly-emerged SARS-CoV-2 and early adaptive immune responses...
SARS-CoV-2 infection in young children and Kawasaki-like disease.
Investigators in the Bergamo province of northern Italy found a 30-fold increased incidence of Kawasaki disease and they report in The Lancet that children diagnosed after the SARS-CoV-2 had a higher rate of cardiac involvement and features of Macrophage Activation Syndrome (MAS). They concluded that young children infected with SARS-CoV-2, rather than develop respiratory illness, progress to a severe form of Kawasaki-like disease...
No evidence that BCG vaccination can protect against SARS-CoV-2 infection.
A research letter published in JAMA network showed that BCG vaccination in childhood had no protective effect against SARS-CoV-2 infection in adulthood. The authors report on a cohort of Israeli adults aged 35 to 41 years who received BCG vaccination in childhood compared with no vaccination and then tested for SARS-CoV-2. There was no statistically significant difference in the proportion of positive tests...
Do we have more T cell immunity to SARS-CoV-2 than we think?
A recently published article in Cell showed the presence of SARS-CoV-2−reactive CD4+ T cells in up to 60% of unexposed individuals – suggesting the presence of cross-reactive T cells. The authors used a set of peptide ‘megapools’, derived from predicted peptides restricted by several HLA class I and II, and found that 70-100% of COVID-19 convalescent patients had reactive...
Is the rapid generation of neutralizing antibodies to SARS-CoV-2 good news for preventing reinfection?
A recent pre-peer reviewed article in medRxiv reports on the dynamics of neutralizing antibody responses to the receptor-binding domain (RBD) of the spike protein. Investigators examined 44 COVID-19 patients and found that class-switching occurred early during infection and was by RBD-specific IgG1 and IgG3 responses. They also detected both RBD-specific IgM ...