Neutralisation Hierarchy of SARS-CoV-2 Variants of Concern Using Standardised, Quantitative Neutralisation Assays Reveals a Correlation With Disease Severity; Towards Deciphering Protective Antibody Thresholds

  1. Diego Cantoni
  2. Martin Mayora-Neto
  3. Angalee Nadesalingam
  4. David A. Wells
  5. George W. Carnell
  6. Luis Ohlendorf
  7. Matteo Ferrari
  8. Phil Palmer
  9. Andrew C.Y. Chan
  10. Peter Smith
  11. Emma M. Bentley
  12. Sebastian Einhauser
  13. Ralf Wagner
  14. Mark Page
  15. Gianmarco Raddi
  16. Helen Baxendale
  17. Javier Castillo-Olivares
  18. Jonathan Heeney
  19. Nigel Temperton

Reviewed by

Read the full article See related articles

Listed in

Log in to save this article

Abstract

The rise of SARS-CoV-2 variants has made the pursuit to define correlates of protection more troublesome, despite the availability of the World Health Organisation (WHO) International Standard for anti-SARS-CoV-2 Immunoglobulin sera, a key reagent used to standardise laboratory findings into an international unitage. Using pseudotyped virus, we examine the capacity of convalescent sera, from a well-defined cohort of healthcare workers (HCW) and Patients infected during the first wave from a national critical care centre in the UK to neutralise B.1.1.298, variants of interest (VOI) B.1.617.1 (Kappa), and four VOCs, B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma) and B.1.617.2 (Delta), including the B.1.617.2 K417N, informally known as Delta Plus. We utilised the WHO International Standard for anti-SARS-CoV-2 Immunoglobulin to report neutralisation antibody levels in International Units per mL. Our data demonstrate a significant reduction in the ability of first wave convalescent sera to neutralise the VOCs. Patients and HCWs with more severe COVID-19 were found to have higher antibody titres and to neutralise the VOCs more effectively than individuals with milder symptoms. Using an estimated threshold for 50% protection, 54 IU/mL, we found most asymptomatic and mild cases did not produce titres above this threshold.

Article activity feed

  1. Version published to 10.3389/fimmu.2022.773982
  2. Version published to 10.1101/2021.05.24.21257729v2 on medRxiv
  3. ScreenIT

    SciScore for 10.1101/2021.05.24.21257729: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    EthicsIRB: COVID-19 patients hospitalised during the first wave and as well as NHS healthcare workers working at RPH served as the exposed HCW cohort (Study approved by Research Ethics Committee Wales, IRAS: 96194 12/WA/0148.
    Consent: All participants provided written, informed consent prior to enrolment in the study.
    Sex as a biological variablenot detected.
    RandomizationA random intercept was used to account for measuring each sample against five variants.
    Blindingnot detected.
    Power Analysisnot detected.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Experimental Models: Cell Lines
    SentencesResources
    Tissue Culture: Human Embryonic Kidney 293T/17 (HEK293T17) cells were maintained in DMEM with 10% foetal bovine serum, 1% penicillin/streptomycin and incubated at 37°C and 5% CO2.
    HEK293T17
    suggested: None
    HEK293T/17 cells expressing ACE/TMPRSS2 were added at 10,000 cells per well.
    HEK293T/17
    suggested: None
    Recombinant DNA
    SentencesResources
    Generation of Spike expression plasmids: The B.1 SARS-CoV-2 Spike expression plasmid (pcDNA3.1+) is based on the Wuhan-Hu-1 sequence and was kindly gifted by Professor Xiao-Ning Xu, Imperial College,
    pcDNA3.1+
    suggested: RRID:Addgene_117272)
    The P.1 variant Spike expression plasmid (pEVAC) was synthesised commercially (GeneArt) with a 19 amino acid C-terminus truncation to increase yields in pseudotyped virus production.
    pEVAC
    suggested: None
    Briefly 1000ng of p8.91 HIV Gag-pol, 1500ng of pCSFLW luciferase and 1000ng of SARS-CoV-2 Spike plasmids were resuspended in Opti-MEM and mixed with FuGENE HD (Promega) at a 1:3 ratio.
    pCSFLW
    suggested: None
    Neutralisation Assays: Pseudotype neutralisation assays (pMN) were carried out as previously described (28).
    pMN
    suggested: RRID:Addgene_18785)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  4. Version published to 10.1101/2021.05.24.21257729v1 on medRxiv