Introduction of Brazilian SARS-CoV-2 484K.V2 related variants into the UK

Toovey, Oliver T R; Harvey, Kirsty N.; Bird, Paul; Tang, Julian W.

doi:10.1016/j.jinf.2021.01.025

Cited by 71 publications

(58 citation statements)

References 4 publications

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“…Our findings are only very slightly affected when taking account of test accuracy (data not shown). Finally, new variants of SARS-CoV-2 with the 484K or 501Y receptor binding area substitutions have recently appeared in Denmark, [32][33][34] with some variants known to be more transmissable then the original. 35,36 During the study period, such variants were not yet established in Denmark; although into 2021 this pattern is changing.…”

Section: Discussionmentioning

confidence: 99%

Assessment of protection against reinfection with SARS-CoV-2 among 4 million PCR-tested individuals in Denmark in 2020: a population-level observational study

et al. 2021

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Background The degree to which infection with SARS-CoV-2 confers protection towards subsequent reinfection is not well described. In 2020, as part of Denmark's extensive, free-of-charge PCR-testing strategy, approximately 4 million individuals (69% of the population) underwent 10•6 million tests. Using these national PCR-test data from 2020, we estimated protection towards repeat infection with SARS-CoV-2. Methods In this population-level observational study, we collected individual-level data on patients who had been tested in Denmark in 2020 from the Danish Microbiology Database and analysed infection rates during the second surge of the COVID-19 epidemic, from Sept 1 to Dec 31, 2020, by comparison of infection rates between individuals with positive and negative PCR tests during the first surge (March to May, 2020). For the main analysis, we excluded people who tested positive for the first time between the two surges and those who died before the second surge. We did an alternative cohort analysis, in which we compared infection rates throughout the year between those with and without a previous confirmed infection at least 3 months earlier, irrespective of date. We also investigated whether differences were found by age group, sex, and time since infection in the alternative cohort analysis. We calculated rate ratios (RRs) adjusted for potential confounders and estimated protection against repeat infection as 1-RR. Findings During the first surge (ie, before June, 2020), 533 381 people were tested, of whom 11 727 (2•20%) were PCR positive, and 525 339 were eligible for follow-up in the second surge, of whom 11 068 (2•11%) had tested positive during the first surge. Among eligible PCR-positive individuals from the first surge of the epidemic, 72 (0•65% [95% CI 0•51-0•82]) tested positive again during the second surge compared with 16 819 (3•27% [3•22-3•32]) of 514 271 who tested negative during the first surge (adjusted RR 0•195 [95% CI 0•155-0•246]). Protection against repeat infection was 80•5% (95% CI 75•4-84•5). The alternative cohort analysis gave similar estimates (adjusted RR 0•212 [0•179-0•251], estimated protection 78•8% [74•9-82•1]). In the alternative cohort analysis, among those aged 65 years and older, observed protection against repeat infection was 47•1% (95% CI 24•7-62•8). We found no difference in estimated protection against repeat infection by sex (male 78•4% [72•1-83•2] vs female 79•1% [73•9-83•3]) or evidence of waning protection over time (3-6 months of follow-up 79•3% [74•4-83•3] vs ≥7 months of follow-up 77•7% [70•9-82•9]). Interpretation Our findings could inform decisions on which groups should be vaccinated and advocate for vaccination of previously infected individuals because natural protection, especially among older people, cannot be relied on.

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Section: Discussionmentioning

confidence: 99%

Assessment of protection against reinfection with SARS-CoV-2 among 4 million PCR-tested individuals in Denmark in 2020: a population-level observational study

et al. 2021

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confidence: 99%

SARS -CoV-2 T-cell immunity to variants of concern following vaccination

Gallagher

Leick

Larson

et al. 2021

Preprint

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Recently, two mRNA vaccines to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have become available, but there is also an emergence of SARS-CoV-2 variants with increased transmissibility and virulence. A major concern is whether the available vaccines will be equally effective against these variants. The vaccines are designed to induce an immune response against the SARS-CoV-2 spike protein, which is required for viral entry to host cells. Immunity to SARS-CoV-2 is often evaluated by antibody production, while less is known about the T-cell response. Here we developed, characterized, and implemented two standardized, functional assays to measure T-cell immunity to SARS-CoV-2 in uninfected, convalescent, and vaccinated individuals. We found that vaccinated individuals had robust T-cell responses to the wild type spike and nucleocapsid proteins, even more so than convalescent patients. We also found detectable but diminished T-cell responses to spike variants (B.1.1.7, B.1.351, and B.1.1.248) among vaccinated but otherwise healthy donors. Since decreases in antibody neutralization have also been observed with some variants, investigation into the T-cell response to these variants as an alternative means of viral control is imperative. Standardized measurements of T-cell responses to SARS-CoV-2 are feasible and can be easily adjusted to determine changes in response to variants.

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“…SARS-CoV-2 is an enveloped, positive-sense, singlestranded RNA beta-coronavirus, being prone to mutate very rapidly, since during RNA replication no error-correction mechanisms is used when copying the RNA genetic information into DNA [25][26][27][28]. Such mutations can confer new features to the virus, including the ability to infect new types of cells, or even new organisms and thus to determine the spillover, and this phenomenon occurred extensively in the case of SARS-CoV-2, as already mentioned here [11][12][13]. Like the preceding two CoVs that provoked outbreaks, SARS-CoV and MERS-CoV, the genome of SARS-CoV-2 encodes for several non-structural proteins (nsps), including several enzymes, such as an RNA-dependent RNA polymerase (RdRp), a helicase, a 3-chymotrypsin-like protease, also known as main protease (MPro) and a papain-like protease (PLP).…”

Section: Coronavirusesmentioning

confidence: 87%

“…The monoclonal antibodies (MAbs) constitute another therapeutic approach that is being pursued, with some highly effective ones discovered from plasma of convalescent COVID-19 patients, now in clinical trials [11]. However, although vaccines and MAbs already showed their efficacy and will definitely be useful to stop or at least slow down the pandemic, the continuous evolution of the virus, which uses a variety of immune escape mechanisms, will probably lead to the emergence of variants which are not neutralized by these agents, as already reported for the South African and Brazilian SARS-CoV-2 strains [12,13]. For these reasons, novel small molecule antiviral drugs capable of impairing the replication of CoV that can be used in the current outbreak and maybe also in future occurrences, are in exceedingly high demand but are scarcely available to date [14].…”

Section: Coronavirusesmentioning

confidence: 97%