A single-dose live-attenuated YF17D-vectored SARS-CoV2 vaccine candidate

  1. Lorena Sanchez Felipe
  2. Thomas Vercruysse
  3. Sapna Sharma
  4. Ji Ma
  5. Viktor Lemmens
  6. Dominique van Looveren
  7. Mahadesh Prasad Arkalagud Javarappa
  8. Robbert Boudewijns
  9. Bert Malengier-Devlies
  10. Suzanne F. Kaptein
  11. Laurens Liesenborghs
  12. Carolien De Keyzer
  13. Lindsey Bervoets
  14. Madina Rasulova
  15. Laura Seldeslachts
  16. Sander Jansen
  17. Michael Bright Yakass
  18. Osbourne Quaye
  19. Li-Hsin Li
  20. Xin Zhang
  21. Sebastiaan ter Horst
  22. Niraj Mishra
  23. Lotte Coelmont
  24. Christopher Cawthorne
  25. Koen Van Laere
  26. Ghislain Opdenakker
  27. Greetje Van de Velde
  28. Birgit Weynand
  29. Dirk E. Teuwen
  30. Patrick Matthys
  31. Johan Neyts
  32. Hendrik Jan Thibaut
  33. Kai Dallmeier

Reviewed by

Read the full article See related articles

Listed in

Log in to save this article

Abstract

The explosively expanding COVID-19 pandemic urges the development of safe, efficacious and fast-acting vaccines to quench the unrestrained spread of SARS-CoV-2. Several promising vaccine platforms, developed in recent years, are leveraged for a rapid emergency response to COVID-19 1 . We employed the live-attenuated yellow fever 17D (YF17D) vaccine as a vector to express the prefusion form of the SARS-CoV-2 Spike antigen. In mice, the vaccine candidate, tentatively named YF-S0, induces high levels of SARS-CoV-2 neutralizing antibodies and a favorable Th1 cell-mediated immune response. In a stringent hamster SARS-CoV-2 challenge model 2 , vaccine candidate YF-S0 prevents infection with SARS-CoV-2. Moreover, a single dose confers protection from lung disease in most vaccinated animals even within 10 days. These results warrant further development of YF-S0 as a potent SARS-CoV-2 vaccine candidate.

Article activity feed

  1. ScreenIT

    SciScore for 10.1101/2020.07.08.193045: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board StatementIRB: Housing conditions and experimental procedures were approved by the Ethical Committee of KU Leuven (license P015-2020), following Institutional Guidelines approved by the Federation of European Laboratory Animal Science Associations (FELASA).
    Randomizationnot detected.
    BlindingTissue sections (5 μm) were stained with hematoxylin and eosin and analyzed blindly for lung damage by an expert pathologist.
    Power Analysisnot detected.
    Sex as a biological variableSix-to ten-weeks-old female mice and wild-type hamsters were used throughout the study.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Secondary antibodies were goat anti-mouse Alexa Fluor-594 and goat anti-rabbit Alexa Fluor-594 (Life Technologies).
    anti-mouse
    suggested: None
    anti-rabbit
    suggested: None
    Briefly, after loading of 400 ng of total protein onto each capillary, specific S protein levels were identified using specific primary antibodies (NB100-56578, Novus Biologicals and 40150-T62-CoV2, Sino Biological Inc.), and HRP conjugated secondary antibody (Protein Simple).
    NB100-56578
    suggested: (Novus Cat# NB100-56578, RRID:AB_838846)
    HRP conjugated secondary antibody ( Protein Simple) .
    suggested: None
    All animals were bled at day 21 to analyze serum for binding and neutralizing antibodies against SARS-CoV-2.
    SARS-CoV-2
    suggested: None
    Detection of total binding IgG and IgG isotyping by indirect immunofluorescent assay (IIFA): To detect SARS-CoV-2 specific antibodies in hamster and mouse serum, an in-house developed indirect IFA (IIFA) was used.
    total binding IgG
    suggested: None
    goat-anti-mouse IgG1, IgG2b and IgG2c Alexa Fluor 488 (respectively 115-545-205, 115-545-207 and 115-545-208 from Jackson ImmunoResearch) were used as secondary antibody.
    goat-anti-mouse IgG1 , IgG2b and IgG2c Alexa Fluor 488 ( respectively 115-545-205 , 115-545-207 and 115-545-208 from Jackson ImmunoResearch )
    suggested: None
    IgG1 , IgG2b
    suggested: (Jackson ImmunoResearch Labs Cat# 115-545-208, RRID:AB_2338857)
    IgG2c
    suggested: (Jackson ImmunoResearch Labs Cat# 115-545-208, RRID:AB_2338857)
    The medium was changed with medium containing anti-VSV-G antibody (I1, mouse hybridoma supernatant from CRL-2700; ATCC) to neutralize any residual VSV-G virus input55.
    anti-VSV-G
    suggested: None
    I1
    suggested: None
    Finally, cells were intracellularly stained with following antibodies: PE anti-IL-4 (11B11)
    anti-IL-4
    suggested: None
    Experimental Models: Cell Lines
    SentencesResources
    BSR-T7/5 (T7 RNA polymerase expressing BHK-21)38 cells were kept in DMEM supplemented with 0.5 mg/ml geneticin (Gibco).
    BHK-21)38
    suggested: None
    YF17D (Stamaril®, Sanofi-Pasteur) was passaged twice in Vero E6 cells before use.
    Vero E6
    suggested: RRID:CVCL_XD71)
    Infectious vaccine viruses were generated from plasmid constructs by transfection into BHK-21J cells using standard protocols (TransIT-LT1, Mirus Bio).
    BHK-21J
    suggested: None
    Immunoblot analysis (Simple Western): Infected BHK21-J cells were harvested and washed once with ice cold phosphate buffered saline, and lysed in radioimmunoprecipitation assay buffer (Thermo Fisher Scientific) containing 1x protease inhibitor and phosphatase inhibitor cocktail (Thermo Fisher Scientific).
    BHK21-J
    suggested: None
    Wild-type Syrian hamsters (Mesocricetus auratus) and BALB/c mice and pups were purchased from Janvier Laboratories, Le Genest-Saint-Isle, France. Ifnar1-/- 41 and AG12942 were bred in-house.
    AG12942
    suggested: Coriell Cat# AG12942, RRID:CVCL_2E88)
    To determine SARS-CoV-2 Spike binding antibody end titers, 1/2 serial serum dilutions were made in 96-well plates on HEK293T-Spike stable cells and HEK293T wt cells in parallel.
    HEK293T-Spike
    suggested: None
    HEK293T
    suggested: NCBI_Iran Cat# C498, RRID:CVCL_0063)
    Briefly, HEK-293T cells were transfected with a pCAGGS-SARS-CoV-2Δ18-Flag expression plasmid encoding SARS-CoV-2 Spike protein carrying a C-terminal 18 amino acids deletion53,54.
    HEK-293T
    suggested: None
    Experimental Models: Organisms/Strains
    SentencesResources
    Immunization of mice: Ifnar1-/- mice were i.p. vaccinated with different vaccine constructs by using a prime and boost of each 4 × 102 PFU (at day 0 and 7).
    Ifnar1-/-
    suggested: None
    Neurovirulence in suckling mice and neurotropism in AG129 mice: BALB/c mice pups and AG129 mice were respectively intracranially or i.p. inoculated with the indicated PFU amount of YF17D and YF-S vaccine constructs and monitored daily for morbidity and mortality for 21 days post inoculation.
    BALB/c
    suggested: None
    AG129
    suggested: None
    Software and Algorithms
    SentencesResources
    Chemiluminescence signals were analyzed using Compass software (Protein Simple).
    Compass
    suggested: (COMPASS, RRID:SCR_015874)
    The percentage of GFP or mCherry expressing cells was quantified on a Cell Insight CX5/7 High Content Screening platform (Thermo Fischer Scientific) and neutralization IC50 values were determined by fitting the serum neutralization dilution curve that is normalized to a virus (100%) and cell control (0%) in Graphpad Prism (GraphPad Software, Inc.).
    Graphpad Prism
    suggested: (GraphPad Prism, RRID:SCR_002798)
    All flow cytometry data were analysed using FlowJo Version 10.6.2 (LLC))
    FlowJo
    suggested: (FlowJo, RRID:SCR_008520)
    Statistical analysis: GraphPad Prism (GraphPad Software, Inc.) was used for all statistical evaluations.
    GraphPad
    suggested: (GraphPad Prism, RRID:SCR_002798)

    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.

    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.

  2. Version published to 10.1101/2020.07.08.193045v1 on bioRxiv