Published: Feb. 9, 2022
About Us: The Ontario COVID-19 Science Advisory Table is a group of scientific experts and health system leaders who evaluate report on emerging evidence relevant to the pandemic, inform Ontario's response.Our mandate provide weekly summaries for Health Coordination Province Ontario, integrating information from existing tables, universities agencies, best global evidence.The summarizes its findings public in Briefs.
Language: Английский
medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2022, Volume and Issue: unknown
Published: Jan. 30, 2022
1 Abstract The Omicron SARS-CoV-2 variant of concern (VOC lineage B.1.1.529), which became dominant in many countries during early 2022, includes several subvariants with strikingly different genetic characteristics. Several countries, including Denmark, have observed the two subvariants: BA.1 and BA.2. In Denmark latter has rapidly replaced former as subvariant. Based on nationwide Danish data, we estimate transmission dynamics BA.2 following spread VOC within households late December 2021 January 2022. Among 8,541 primary household cases, 2,122 were BA.2, identified a total 5,702 secondary infections among 17,945 potential cases 1-7 day follow-up period. attack rate (SAR) was estimated 29% 39% infected respectively. We found to be associated an increased susceptibility infection for unvaccinated individuals (Odds Ratio (OR) 2.19; 95%-CI 1.58-3.04), fully vaccinated (OR 2.45; 1.77-3.40) booster-vaccinated 2.99; 2.11-4.24), compared BA.1. also transmissibility from when households, OR 2.62 (95%-CI 1.96-3.52). pattern not where below conclude that is inherently substantially more transmissible than BA.1, it possesses immune-evasive properties further reduce protective effect vaccination against infection, but do increase its breakthrough infections.
Language: Английский
Citations
206
Medical Microbiology and Immunology, Journal Year: 2022, Volume and Issue: 211(2-3), P. 105 - 117
Published: Feb. 20, 2022
Since autumn 2020, rapid antigen tests (RATs) have been implemented in several countries as an important pillar of the national testing strategy to rapidly screen for infections on site during SARS-CoV-2 pandemic. The current surge infection rates around globe is driven by variant concern (VoC) omicron (B.1.1.529). Here, we evaluated performance nine RATs a single-centre laboratory study. We examined total 115 PCR-negative and 166 PCR-positive respiratory swab samples (101 omicron, 65 delta (B.1.617.2)) collected from October 2021 until January 2022 well cell culture-expanded clinical isolates both VoCs. In assessment analytical sensitivity specimen, 50% limit detection (LoD50) ranged 1.77 × 10
Language: Английский
Citations
116
Annals of Internal Medicine, Journal Year: 2022, Volume and Issue: 175(9), P. 1258 - 1265
Published: July 4, 2022
Immunoassays for determining past SARS-CoV-2 infection have not been systematically evaluated in vaccinated persons comparison with unvaccinated persons.
Language: Английский
Citations
111
Viruses, Journal Year: 2022, Volume and Issue: 14(2), P. 187 - 187
Published: Jan. 19, 2022
Sterilizing immunity after vaccination is desirable to prevent the spread of infection from vaccinees, which can be especially dangerous in hospital settings while managing frail patients. requires neutralizing antibodies at site infection, for respiratory viruses such as SARS-CoV-2 implies occurrence IgA mucosal secretions. Systemic by intramuscular delivery induces no or low-titer against vaccine antigens. Mucosal priming boosting, needed provide sterilizing immunity. On other side coin, immunity, zeroing interhuman transmission, could confine animal reservoirs, preventing spontaneous attenuation virulence humans presumably happened with endemic coronaviruses. We review here pros and cons each strategy, current vaccines under development, their implications public health.
Language: Английский
Citations
88
medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2022, Volume and Issue: unknown
Published: Jan. 14, 2022
Abstract Background The combined impact of immunity and SARS-CoV-2 variants on viral kinetics during infections has been unclear. Methods We characterized 2,875 from the National Basketball Association occupational health cohort identified between June 2020 January 2022 using serial RT-qPCR testing. Logistic regression semi-mechanistic RNA models were used to quantify effect variant, symptom status, age, infection history, vaccination antibody titer founder strain duration potential infectiousness overall kinetics. frequency rebounds was quantified under multiple cycle threshold (Ct) value-based definitions. Results Among individuals detected partway through their infection, 51.0% (95% credible interval [CrI]: 48.2-53.6%) remained potentially infectious (Ct<30) five days post detection, with small differences across history. Only seven (0.7%; N=999) observed, rebound defined as 3+ Ct<30 following an initial clearance Ct≥30. High titers against predicted lower peak loads shorter durations infection. Omicron BA.1 infections, boosted had pre-booster longer times than non-boosted individuals. Conclusions are partly determined by variant but dominated individual-level variation. Since booster protects for BA.1-infected, may reflect a less effective immune response, more common in older individuals, that increases risk reduces rate. shifting landscape underscores need continued monitoring optimize isolation policies contextualize impacts therapeutics vaccines. Funding Supported part CDC contract 200-2016-91779, Emergent Ventures at Mercatus Center, Huffman Family Donor Advised Fund, MorrisSinger Association, Players Association.
Language: Английский
Citations
70
Clinical Microbiology Reviews, Journal Year: 2022, Volume and Issue: 35(3)
Published: June 6, 2022
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) keeps evolving and mutating into newer variants over time, which gain higher transmissibility, disease severity, spread in communities at a faster rate, resulting multiple waves of surge Coronavirus Disease 2019 (COVID-19) cases. A highly mutated transmissible SARS-CoV-2 Omicron variant has recently emerged, driving the extremely high peak infections almost all continents an unprecedented speed scale. The evades protection rendered by vaccine-induced antibodies natural infection, as well overpowers antibody-based immunotherapies, raising concerns current effectiveness available vaccines monoclonal therapies. This review outlines most recent advancements studying virology biology variant, highlighting its increased resistance to therapeutics immune escape against vaccines. However, is sensitive viral fusion inhibitors targeting HR1 motif spike protein, enzyme inhibitors, involving endosomal pathway, ACE2-based entry inhibitors. variant-associated infectivity mechanisms are essentially distinct from previous characterized variants. Innate sensing evasion T cell immunity virus provide new perspectives vaccine drug development. These findings important for understanding advances developing vaccines, therapies, more effective strategies mitigate transmission or next concern.
Language: Английский
Citations
68
Viruses, Journal Year: 2022, Volume and Issue: 14(5), P. 919 - 919
Published: April 28, 2022
High viral load in upper respiratory tract specimens observed for Delta cases might contribute to its increased infectivity compared the other variant. However, it is not yet documented if Omicron variant's enhanced also related a higher load. Our aim was determine spread loads variant.Nasopharyngeal swabs, 129 (Omicron) and 85 (Delta), from Health Care Workers were collected during December 2021 at University Hospital of Lyon, France. Cycle threshold (Ct) RdRp target cobas® 6800 SARS-CoV-2 assay used as proxy evaluate Variant identification performed using screening panel confirmed by whole genome sequencing.Herein, we showed that RT-PCR Ct values sampled within 5 days after symptom onset significantly than (21.7 variant 23.8 variant, p = 0.008). This difference regarding patient with complete vaccination.This result supports studies showing transmissibility mechanisms virus excretion.
Language: Английский
Citations
59
Annals of Internal Medicine, Journal Year: 2022, Volume and Issue: 175(5), P. 682 - 690
Published: March 14, 2022
SARS-CoV-2 rapid antigen tests are an important public health tool.
Language: Английский
Citations
57
Vaccine, Journal Year: 2023, Volume and Issue: 41(20), P. 3292 - 3300
Published: April 5, 2023
Vaccine effectiveness against transmission (VET) of SARS-CoV-2-infection can be estimated from secondary attack rates observed during contact tracing. We VET, the vaccine-effect on infectiousness index case and susceptibility high-risk exposure (HREC).We fitted RT-PCR-test results HREC to immunity status (vaccine schedule, prior infection, time since last immunity-conferring event), age, sex, calendar week sampling, household, background positivity rate dominant VOC using a multilevel Bayesian regression-model. included Belgian data collected between January 2021 2022.For primary BNT162b2-vaccination we initial VET at 96% (95%CI 95-97) Alpha, 87% 84-88) Delta 31% 25-37) Omicron. Initial booster-vaccination (mRNA booster-vaccination) was 86-89) 68% 65-70) The VET-estimate Omicron decreased 71% 64-78) 55% 46-62) respectively, 150-200 days after booster-vaccination. Hybrid immunity, defined as vaccination documented associated with durable higher or comparable (by number antigen exposures) protection transmission.While VOC-specific immune-escape, especially by Omicron, waning over immunization, remained reduced risk SARS-CoV-2-transmission.
Language: Английский
Citations
39
medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2021, Volume and Issue: unknown
Published: Dec. 22, 2021
Abstract Background The emergence of each novel SARS-CoV-2 variants concern (VOCs) requires investigation its potential impact on the performance diagnostic tests in use, including Antigen-detecting rapid (Ag-RDT). Although anecdotal reports have been circulating that newly emerged Omicron variant is principle detectable by Ag-RDTs, few data sensitivity are available. Methods We performed 1) analytical testing with cultured virus eight Ag-RDTs and 2) retrospective duplicates clinical samples from vaccinated individuals (n=18) or Delta (n=17) breakthrough infection seven Ag-RDTs. Findings Overall, we found large heterogenicity between for detecting Omicron. When using virus, observed a trend towards lower detection compared to earlier other VOCs. comparing comparable set 124/252 (49.2%) all test showed positive result 156/238 (65.6%) samples. Sensitivity both was highly variable. Four out significantly (p<0.001) detect when while three had Delta. Interpretation variable necessitating careful consideration these guide prevention measures. While may be proxy timely solution generate data, it not replacement evaluations which urgently needed. Biological technical reasons failure some need further investigated. Funding This work supported Swiss National Science Foundation (grant numbers 196383, 196644 198412), Fondation Ancrage Bienfaisance du Groupe Pictet, Privée des Hôpiteaux Universitaires de Genève FIND, global alliance diagnostics.
Language: Английский
Citations
48