In recent months, multiple lineages of the omicron (B.1.1.529) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged,1 with subvariants BA.1 and BA.2 showing substantial escape from neutralizing antibodies.2-5 Subvariant BA.2.12.1 is now the dominant strain in the United States, and BA.4 and BA.5 are dominant in South Africa (Figure 1A). Subvariants BA.4… Continue reading Neutralization Escape by SARS-CoV-2 Omicron Subvariants BA.2.12.1, BA.4, and BA.5
Tag: omicron
Estimating disease severity of Omicron and Delta SARS-CoV-2 infections
The Omicron variant of SARS-CoV-2 has been reported to cause milder disease in adults but lead to increased hospital admissions in children. How can we compare disease severity in Omicron and Delta infections, and how should differences be interpreted? Measuring COVID-19 disease severity in a population has been important for understanding the public health impact… Continue reading Estimating disease severity of Omicron and Delta SARS-CoV-2 infections
Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant
BACKGROUNDA rapid increase in coronavirus disease 2019 (Covid-19) cases due to the omicron (B.1.1.529) variant of severe acute respiratory syndrome coronavirus 2 in highly vaccinated populations has aroused concerns about the effectiveness of current vaccines. METHODSWe used a test-negative case–control design to estimate vaccine effectiveness against symptomatic disease caused by the omicron and delta (B.1.617.2)… Continue reading Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant
Effectiveness of mRNA-1273 against SARS-CoV-2 Omicron and Delta variants
SARS-CoV-2 Omicron (B.1.1.529) variant is highly transmissible with potential immune escape. We conducted a test-negative case-control study to evaluate mRNA-1273 vaccine effectiveness (VE) against infection and hospitalization with Omicron or Delta. The large, diverse study population included 26,683 SARS-CoV-2 test-positive cases with variants determined by S-gene target failure status (16% Delta, 84% Omicron). The 2-dose… Continue reading Effectiveness of mRNA-1273 against SARS-CoV-2 Omicron and Delta variants
Fourth Dose COVID mRNA Vaccines’ Immunogenicity & Efficacy Against Omicron VOC
AbstractBACKGROUND Following the emergence of the Omicron variant of concern, we investigated immunogenicity, efficacy and safety of BNT162b2 or mRNA1273 fourth dose in an open-label, clinical intervention trial. METHODS Primary end-points were safety and immunogenicity and secondary end-points were vaccine efficacy in preventing SARS-CoV-2 infections and COVID-19 symptomatic disease. The two intervention arms were compared… Continue reading Fourth Dose COVID mRNA Vaccines’ Immunogenicity & Efficacy Against Omicron VOC
Rapid emergence of SARS-CoV-2 Omicron variant is associated with an infection advantage over Delta in vaccinated persons
The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants continues to shape the coronavirus disease 2019 (Covid-19) pandemic. The detection and rapid spread of the SARS-CoV-2 Omicron variant (lineage B.1.1.529) in Botswana and South Africa became a global concern because it contained 15 mutations in the spike protein immunogenic receptor binding domain and… Continue reading Rapid emergence of SARS-CoV-2 Omicron variant is associated with an infection advantage over Delta in vaccinated persons
Early estimates of SARS-CoV-2 Omicron variant severity based on a matched cohort study, Ontario, Canada
While it is now evident that Omicron is rapidly replacing Delta, largely due to immune escape, it is less clear how the severity of Omicron compares to Delta. In Ontario, we sought to examine hospitalization and death associated with Omicron, as compared to cases infected with Delta. We conducted a matched cohort study, considering time… Continue reading Early estimates of SARS-CoV-2 Omicron variant severity based on a matched cohort study, Ontario, Canada
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