Efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine against SARS-CoV-2 lineages circulating in Brazil

Article Medicine, General & Internal

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK

Merryn Voysey et al.

Summary: The ChAdOx1 nCoV-19 vaccine has been shown to have an acceptable safety profile and effectiveness against symptomatic COVID-19, with higher efficacy observed in the group that received a low dose followed by a standard dose.

LANCET (2021)

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Article Multidisciplinary Sciences

Three-quarters attack rate of SARS-CoV-2 in the Brazilian Amazon during a largely unmitigated epidemic

Lewis F. Buss et al.

Summary: Research indicates that the attack rate of COVID-19 in Manaus, the capital of Amazonas state in northern Brazil, reached 66% in June 2020, rising to 76% by October, higher than the estimated attack rate of 29% in Sao Paulo, southeastern Brazil, during the same period.

SCIENCE (2021)

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Article Biochemistry & Molecular Biology

Evidence of escape of SARS-CoV-2 variant B.1.351 from natural and vaccine-induced sera

Daming Zhou et al.

Summary: The race to develop vaccines against SARS-CoV-2 variants, such as B.1.1.7, B.1.351, and P.1, is ongoing as these variants have mutations in the spike protein, potentially leading to immune escape. A structure-function analysis of B.1.351 revealed tighter ACE2 binding and widespread evasion from monoclonal antibody neutralization, particularly driven by the E484K mutation.

CELL (2021)

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Article Medicine, General & Internal

Single-dose administration and the influence of the timing of the booster dose on immunogenicity and efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine: a pooled analysis of four randomised trials

Merryn Voysey et al.

Summary: The AZD1222 vaccine has been approved for emergency use in the UK with an interval of 4-12 weeks between doses. Analysis shows that the vaccine is efficacious with two doses and provides immunoprotection after the first dose before the second dose is administered.

LANCET (2021)

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Editorial Material Medicine, General & Internal

Resurgence of COVID-19 in Manaus, Brazil, despite high seroprevalence

Ester C. Sabino et al.

LANCET (2021)

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Article Multidisciplinary Sciences

Sensitivity of SARS-CoV-2 B.1.1.7 to mRNA vaccine-elicited antibodies

Dami A. Collier et al.

Summary: The B.1.1.7 variant of SARS-CoV-2 exhibited reduced neutralization by vaccines and antibodies from recovered COVID-19 patients, with a more substantial loss seen when introducing the E484K mutation. This mutation poses a threat to the efficacy of the BNT162b2 vaccine.

NATURE (2021)

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Article Medicine, General & Internal

BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Mass Vaccination Setting

Noa Dagan et al.

Summary: A study conducted in Israel on nearly 600,000 individuals showed that the BNT162b2 mRNA vaccine was effective in reducing the risk of infection, hospitalization, and severe Covid-19. The effectiveness in preventing death was 72% during the period from day 14 through day 20 after the first dose, and hospitalization was reduced by 87% for the period 7 or more days after the second dose, similar to results from a randomized trial.

NEW ENGLAND JOURNAL OF MEDICINE (2021)

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Article Multidisciplinary Sciences

SARS-CoV-2 within-host diversity and transmission

Katrina A. Lythgoe et al.

Summary: The study found that SARS-CoV-2 infections in clinical samples in the UK are characterized by low levels of within-host diversity and a narrow bottleneck at transmission. Most variants are either lost or occasionally fixed at the point of transmission, with shared diversity not persisting.

SCIENCE (2021)

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Article Medicine, General & Internal

SARS-CoV-2 infection rates of antibody-positive compared with antibody-negative health-care workers in England: a large, multicentre, prospective cohort study (SIREN)

Victoria Jane Hall et al.

Summary: This study investigated whether antibodies against SARS-CoV-2 were associated with a decreased risk of symptomatic and asymptomatic reinfection. It found that individuals with a previous history of SARS-CoV-2 infection had an 84% lower risk of reinfection, with a median protective effect lasting for 7 months following primary infection.

LANCET (2021)

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Article Medicine, General & Internal

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

Katherine R. W. Emary et al.

Summary: A post-hoc analysis was conducted on the efficacy of the ChAdOx1 nCoV-19 vaccine against the B.1.1.7 variant of SARS-CoV-2 in the UK. The vaccine showed reduced neutralisation activity against the B.1.1.7 variant in vitro, but still demonstrated efficacy against the B.1.1.7 variant of the virus.

LANCET (2021)

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Letter Medicine, General & Internal

Effectiveness of the BNT162b2 Covid-19 Vaccine against the B.1.1.7 and B.1.351 Variants

Laith J. Abu-Raddad et al.

NEW ENGLAND JOURNAL OF MEDICINE (2021)

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Article Medicine, General & Internal

Efficacy of the ChAdOx1 nCoV-19 Covid-19 Vaccine against the B.1.351 Variant

S. A. Madhi et al.

Summary: The ChAdOx1 nCoV-19 vaccine did not provide significant protection against mild-to-moderate Covid-19 caused by the B.1.351 variant, with an efficacy of 10.4%. The incidence of serious adverse events was balanced between the vaccine and placebo groups.

NEW ENGLAND JOURNAL OF MEDICINE (2021)

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Article Medicine, General & Internal

Efficacy of NVX-CoV2373 Covid-19 Vaccine against the B.1.351 Variant

V. Shinde et al.

Summary: The NVX-CoV2373 vaccine showed efficacy in preventing Covid-19, with higher vaccine efficacy observed among HIV-negative participants. Most infections were caused by the B.1.351 variant.

NEW ENGLAND JOURNAL OF MEDICINE (2021)

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Article Multidisciplinary Sciences

Genomics and epidemiology of the P.1 SARS-CoV-2 lineage in Manaus, Brazil

Nuno R. Faria et al.

Summary: A new variant of concern, P.1, with 17 mutations including three spike protein mutations associated with increased binding to human ACE2 receptors, emerged in Manaus, Brazil between November 2020 and January 2021. Molecular analysis suggests P.1 may be 1.7- to 2.4-fold more transmissible and that previous infection may provide 54 to 79% protection against P.1 infection compared to other lineages. Enhanced global genomic surveillance of such variants is crucial for pandemic response.

SCIENCE (2021)

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Article Biochemistry & Molecular Biology

COVID-19 in Amazonas, Brazil, was driven by the persistence of endemic lineages and P.1 emergence

Felipe Gomes Naveca et al.

Summary: Analysis of circulating SARS-CoV-2 viruses during the first and second waves of COVID-19 in Amazonas, Brazil, shows successive lineage replacements led to predominance of the variant of concern P.1 and are associated with variable levels of social distancing.

NATURE MEDICINE (2021)

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Letter Infectious Diseases

SARS-CoV-2 spike E484K mutation reduces antibody neutralisation

Sonia Jangra et al.

LANCET MICROBE (2021)

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Letter Immunology

Genomic Evidence of SARS-CoV-2 Reinfection Involving E484K Spike Mutation, Brazil

Carolina Kymie Vasques Nonaka et al.

Summary: The case of reinfection from distinct virus lineages in Brazil with the E484K mutation raises concerns about the duration of protective immune responses against SARS-CoV-2, especially with the variant associated with escape from neutralizing antibodies. This highlights potential challenges for virus control measures.

EMERGING INFECTIOUS DISEASES (2021)

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Article Medicine, General & Internal