Efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine against SARS-CoV-2 variant of concern 202012/01 (B.1.1.7): an exploratory analysis of a randomised controlled trial

The Lancet, Journal Year: 2021, Volume and Issue: 397(10282), P. 1351 - 1362

Published: March 31, 2021

Summary

Background

A new variant of SARS-CoV-2, B.1.1.7, emerged as the dominant cause COVID-19 disease in UK from November, 2020. We report a post-hoc analysis efficacy adenoviral vector vaccine, ChAdOx1 nCoV-19 (AZD1222), against this variant.

Methods

Volunteers (aged ≥18 years) who were enrolled phase 2/3 vaccine studies UK, and randomly assigned (1:1) to receive or meningococcal conjugate control (MenACWY) provided upper airway swabs on weekly basis also if they developed symptoms (a cough, fever 37·8°C higher, shortness breath, anosmia, ageusia). Swabs tested by nucleic acid amplification test (NAAT) for SARS-CoV-2 positive samples sequenced through Genomics consortium. Neutralising antibody responses measured using live-virus microneutralisation assay B.1.1.7 lineage canonical non-B.1.1.7 (Victoria). The included symptomatic seronegative participants with NAAT swab more than 14 days after second dose vaccine. Participants analysed according received. Vaccine was calculated 1 − relative risk (ChAdOx1 vs MenACWY groups) derived robust Poisson regression model. This study is continuing registered ClinicalTrials.gov, NCT04400838, ISRCTN, 15281137.

Findings

cohorts recruited between May 31 Nov 13, 2020, received booster doses Aug 3 Dec 30, Of 8534 primary cohort, 6636 (78%) aged 18–55 years 5065 (59%) female. Between Oct 1, Jan 14, 2021, 520 infection. 1466 nose throat collected these during trial. these, 401 311 successfully sequenced. Laboratory virus neutralisation activity vaccine-induced antibodies lower Victoria (geometric mean ratio 8·9, 95% CI 7·2–11·0). Clinical infection 70·4% (95% 43·6–84·5) 81·5% (67·9–89·4) lineages.

Interpretation

showed reduced compared vitro, but SARS-CoV-2.

Funding

Research Innovation, National Institute Health (NIHR), Coalition Epidemic Preparedness Innovations, NIHR Oxford Biomedical Centre, Thames Valley South Midlands Network, AstraZeneca.

Language: Английский

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The changing epidemiology of SARS-CoV-2

Science, Journal Year: 2022, Volume and Issue: 375(6585), P. 1116 - 1121

Published: March 10, 2022

We have come a long way since the start of COVID-19 pandemic-from hoarding toilet paper and wiping down groceries to sending our children back school vaccinating billions. Over this period, global community epidemiologists evolutionary biologists has also in understanding complex changing dynamics severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), virus that causes COVID-19. In Review, we retrace steps through questions faced as pandemic unfolded. focus on key roles mathematical modeling quantitative analyses empirical data played allowing us address these ultimately better understand control pandemic.

Language: Английский

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Towards an accurate and systematic characterisation of persistently asymptomatic infection with SARS-CoV-2

The Lancet Infectious Diseases, Journal Year: 2020, Volume and Issue: 21(6), P. e163 - e169

Published: Dec. 7, 2020

Language: Английский

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COVID-19 false dichotomies and a comprehensive review of the evidence regarding public health, COVID-19 symptomatology, SARS-CoV-2 transmission, mask wearing, and reinfection

BMC Infectious Diseases, Journal Year: 2021, Volume and Issue: 21(1)

Published: July 27, 2021

Scientists across disciplines, policymakers, and journalists have voiced frustration at the unprecedented polarization misinformation around coronavirus disease 2019 (COVID-19) pandemic. Several false dichotomies been used to polarize debates while oversimplifying complex issues. In this comprehensive narrative review, we deconstruct six common COVID-19 dichotomies, address evidence on these topics, identify insights relevant effective pandemic responses, highlight knowledge gaps uncertainties. The topics of review are: 1) Health lives vs. economy livelihoods, 2) Indefinite lockdown unlimited reopening, 3) Symptomatic asymptomatic severe acute respiratory syndrome 2 (SARS-CoV-2) infection, 4) Droplet aerosol transmission SARS-CoV-2, 5) Masks for all no masking, 6) SARS-CoV-2 reinfection reinfection. We discuss importance multidisciplinary integration (health, social, physical sciences), multilayered approaches reducing risk ("Emmentaler cheese model"), harm reduction, smart relaxation interventions, context-sensitive policymaking response plans. also challenges in understanding broad clinical presentation COVID-19, transmission, These key issues science public health policy presented as during However, they are hardly binary, simple, or uniform, therefore should not be framed polar extremes. urge a nuanced caution against black-or-white messaging, all-or-nothing guidance, one-size-fits-all approaches. There is need meaningful communication science-informed policies that recognize shades gray, uncertainties, local context, social determinants health.

Language: Английский

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Asymptomatic transmission of covid-19

BMJ, Journal Year: 2020, Volume and Issue: unknown, P. m4851 - m4851

Published: Dec. 21, 2020

The UK's £100bn "Operation Moonshot" to roll out mass testing for covid-19 cities and universities around the country raises two key questions.How infectious are people who test positive but have no symptoms?And, what is their contribution transmission of live virus?

Language: Английский

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Factors Associated With Household Transmission of SARS-CoV-2

JAMA Network Open, Journal Year: 2021, Volume and Issue: 4(8), P. e2122240 - e2122240

Published: Aug. 27, 2021

Importance

A previous systematic review and meta-analysis of household transmission SARS-CoV-2 that summarized 54 published studies through October 19, 2020, found an overall secondary attack rate (SAR) 16.6% (95% CI, 14.0%-19.3%). However, the understanding rates for is still evolving, updated analysis needed.

Objective

To use newly data to further in household.

Data Sources

PubMed reference lists eligible articles were used search records between 20, June 17, 2021. No restrictions on language, study design, time, or place publication applied. Studies as preprints included.

Study Selection

Articles with original reported at least 2 following factors included: number contacts infection, total contacts, among contacts. infection prevalence (which includes index cases), tested using antibody tests only, included populations overlapping another excluded. Search terms wereSARS-CoV-2orCOVID-19withsecondary rate,household,close contacts,contact transmission,contact rate, orfamily transmission. Extraction Synthesis Meta-analyses performed generalized linear mixed models obtain SAR estimates 95% CIs. The Preferred Reporting Items Systematic Reviews (PRISMA) reporting guideline was followed.

Main Outcomes Measures

Overall SARS-CoV-2, by covariates (contact age, sex, ethnicity, comorbidities, relationship; case symptom status, presence fever, cough; contacts; location; variant), identification period.

Results

2722 (2710 from database searches 12 articles) 2021, identified. Of those, 93 full-text assessed eligibility, 37 These new combined 50 (published 2020) our (4 Wuhan, China, excluded because their overlapped recent study), resulting a 87 representing 1 249 163 30 countries. estimated all 18.9% 16.2%-22.0%). Compared January February July 2020 March 2021 higher (13.4% [95% 10.7%-16.7%] vs 31.1% 22.6%-41.1%], respectively). Results subgroup analyses similar those meta-analysis; however, comorbidities (3 studies; 50.0% 41.4%-58.6%]) compared findings, B.1.1.7 (α) variant 24.5% 10.9%-46.2%).

Conclusions Relevance

findings this suggest remains important site transmission, have earliest reports. More transmissible variants vaccines may be associated changes.

Language: Английский

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Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Transmission Dynamics Should Inform Policy

Clinical Infectious Diseases, Journal Year: 2020, Volume and Issue: 73(Supplement_2), P. S170 - S176

Published: Sept. 21, 2020

It is generally agreed that striking a balance between resuming economic and social activities keeping the effective reproductive number (R0) below 1 using nonpharmaceutical interventions an important goal until even after vaccines become available. Therefore, need remains to understand how virus transmitted in order identify high-risk environments disproportionately contribute its spread so preventative measures could be put place. Contact tracing household studies, particular, provide robust evidence about parameters of transmission. In this Viewpoint, we discuss available from large-scale, well-conducted contact-tracing studies across world argue severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission dynamics should inform policy decisions mitigation strategies for targeted according needs society by directing attention settings, activities, socioeconomic factors associated with highest risks

Language: Английский

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A systematic review of droplet and aerosol generation in dentistry

Journal of Dentistry, Journal Year: 2020, Volume and Issue: 105, P. 103556 - 103556

Published: Dec. 23, 2020

This review aimed to identify which dental procedures generate droplets and aerosols with subsequent contamination, for these, characterise their pattern, spread settle.Medline(OVID), Embase(OVID), Cochrane Central Register of Controlled Trials, Scopus, Web Science LILACS databases were searched eligible studies from each database's inception May 2020 (search updated 11/08/20). Studies investigating clinical activities that aerosol using duplicate independent screening. Data extraction by one reviewer verified another. Risk bias assessed through contamination measurement tool sensitivity assessment.A total eighty-three met the inclusion criteria covered: ultrasonic scaling (USS, n = 44), highspeed air-rotor (HSAR, 31); oral surgery (n 11), slow-speed handpiece 4); air-water (triple) syringe 4), air-polishing prophylaxis 2) hand-scaling 2). Although no investigated respiratory viruses, those on bacteria, blood-splatter showed powered devices produced greatest contamination. Contamination was found all activities, at furthest points studied. The operator's torso, arm patient's body especially affected. Heterogeneity precluded inter-study comparisons but intra-study allowed construction a proposed hierarchy procedure risk: higher HSAR, syringe, air polishing, extractions motorised handpieces); moderate (slow-speed handpieces, prophylaxis, extractions) lower (air-water [water only] hand scaling).Gaps in evidence, low measures variable quality limit conclusions around procedures. A is challenge/verification future research should consider standardised methodologies facilitate synthesis.This manuscript addresses uncertainty generating (AGPs) dentistry. Findings indicate continuum procedure-related generation rather than common binary AGP or non-AGP perspective. findings inform discussion AGPs direct support knowledge decision making COVID-19

Language: Английский

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Advances in nucleic acid amplification techniques (NAATs): COVID-19 point-of-care diagnostics as an example

Biosensors and Bioelectronics, Journal Year: 2022, Volume and Issue: 206, P. 114109 - 114109

Published: Feb. 26, 2022

Language: Английский

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Vaccination with BNT162b2 reduces transmission of SARS-CoV-2 to household contacts in Israel

Science, Journal Year: 2022, Volume and Issue: 375(6585), P. 1151 - 1154

Published: Jan. 27, 2022

The effectiveness of vaccines against COVID-19 on the individual level is well established. However, few studies have examined vaccine transmission. We used a chain binomial model to estimate vaccination with BNT162b2 [Pfizer-BioNTech messenger RNA (mRNA)-based vaccine] household transmission severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Israel before and after emergence B.1.617.2 (Delta) variant. Vaccination reduced susceptibility infection by 89.4% [95% confidence interval (CI): 88.7 90.0%], whereas infectiousness given was 23.0% (95% CI: -11.3 46.7%) during days 10 90 second dose, 1 June 2021. Total 91.8% 88.1 94.3%). over time as result combined effect waning immunity Delta

Language: Английский

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