Gamma-irradiated SARS-CoV-2 vaccine candidate, OZG-38.61.3, confers protection from SARS-CoV-2 challenge in human ACEII-transgenic mice

  1. Raife Dilek Turan
  2. Cihan Tastan
  3. Derya Dilek Kancagi
  4. Bulut Yurtsever
  5. Gozde Sir Karakus
  6. Samed Ozer
  7. Selen Abanuz
  8. Didem Cakirsoy
  9. Gamze Tumentemur
  10. Sevda Demir
  11. Utku Seyis
  12. Recai Kuzay
  13. Muhammer Elek
  14. Miyase Ezgi Kocaoglu
  15. Gurcan Ertop
  16. Serap Arbak
  17. Merve Acikel Elmas
  18. Cansu Hemsinlioglu
  19. Ozden Hatirnaz Ng
  20. Sezer Akyoney
  21. Ilayda Sahin
  22. Cavit Kerem Kayhan
  23. Fatma Tokat
  24. Gurler Akpinar
  25. Murat Kasap
  26. Ayse Sesin Kocagoz
  27. Ugur Ozbek
  28. Dilek Telci
  29. Fikrettin Sahin
  30. Koray Yalcin
  31. Siret Ratip
  32. Umit Ince
  33. Ercument Ovali

Reviewed by

Read the full article See related articles

Listed in

Log in to save this article

Abstract

The SARS-CoV-2 virus caused the most severe pandemic around the world, and vaccine development for urgent use became a crucial issue. Inactivated virus formulated vaccines such as Hepatitis A and smallpox proved to be reliable approaches for immunization for prolonged periods. In this study, a gamma-irradiated inactivated virus vaccine does not require an extra purification process, unlike the chemically inactivated vaccines. Hence, the novelty of our vaccine candidate (OZG-38.61.3) is that it is a non-adjuvant added, gamma-irradiated, and intradermally applied inactive viral vaccine. Efficiency and safety dose (either 10 13 or 10 14 viral RNA copy per dose) of OZG-38.61.3 was initially determined in BALB/c mice. This was followed by testing the immunogenicity and protective efficacy of the vaccine. Human ACE2-encoding transgenic mice were immunized and then infected with the SARS-CoV-2 virus for the challenge test. This study shows that vaccinated mice have lowered SARS-CoV-2 viral RNA copy numbers both in oropharyngeal specimens and in the histological analysis of the lung tissues along with humoral and cellular immune responses, including the neutralizing antibodies similar to those shown in BALB/c mice without substantial toxicity. Subsequently, plans are being made for the commencement of Phase 1 clinical trial of the OZG-38.61.3 vaccine for the COVID-19 pandemic.

Article activity feed

  1. Version published to 10.1038/s41598-021-95086-4
  2. Version published to 10.1101/2020.10.28.356667v3 on bioRxiv
  3. Version published to 10.1101/2020.10.28.356667v2 on bioRxiv
  4. ScreenIT

    SciScore for 10.1101/2020.10.28.356667: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board StatementIRB: The study for SARS-CoV-2 genome sequencing was approved by the Ethics Committee of Acibadem Mehmet Ali Aydinlar University (ATADEK-2020/05/41) and informed consent from the patients was obtained to publish identifying information/images.
    IACUC: All animal studies received ethical approval by the Acibadem Mehmet Ali Aydinlar University Animal Experiments Local Ethics Committee (ACU-HADYEK).
    RandomizationBALB/c mice were randomly allocated into 3 groups, a negative control group (n=5) and 2 different dose groups (dose of 1×1013 and 1×1014, n = 5 per group).
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variableBalb/c mice test: To analyze the efficiency and toxicology of the dose of inactive vaccine candidate parallel to challenge, 15 Female BALB/c mice were utilized from Acibadem Mehmet Ali Aydinlar University Laboratory Animal Application and Research Center (ACUDEHAM; Istanbul, Turkey).
    Cell Line AuthenticationContamination: (Osmometer, freezing point depression), Ph, Glucose, Albumin (Dimension EX-L), sterility, mycoplasma, endotoxin level, and impurity assay were performed in Acibadem Labmed Laboratory with accredited methods.

    Table 2: Resources

    Antibodies
    SentencesResources
    To detect the SARS-COV-2 IgG antibody in mouse serum SARS-CoV-2 IgG ELISA Kit (Creative, DEIASL019) was used.
    SARS-COV-2 IgG
    suggested: None
    500,000 cells in 100 μl were added into microplate already coated with a monoclonal antibody specific for mouse IFN-γ.
    IFN-γ
    suggested: None
    Also, to determine T cell activation and proliferation, the restimulated cells were stained with the antibodies including CD3, CD4, CD8, and CD25 as an activation marker (Miltenyi Biotec).
    CD3
    suggested: None
    CD4
    suggested: None
    CD8
    suggested: (Diaclone Cat# 873.023.050, RRID:AB_1587082)
    CD25
    suggested: None
    Experimental Models: Cell Lines
    SentencesResources
    As a negative control, only 100 μl pyrogen-free water was inoculated into Vero cells and cultured for 21 days with the same treatments.
    Vero
    suggested: None
    Experimental Models: Organisms/Strains
    SentencesResources
    Balb/c mice test: To analyze the efficiency and toxicology of the dose of inactive vaccine candidate parallel to challenge, 15 Female BALB/c mice were utilized from Acibadem Mehmet Ali Aydinlar University Laboratory Animal Application and Research Center (ACUDEHAM; Istanbul, Turkey).
    BALB/c
    suggested: RRID:IMSR_ORNL:BALB/cRl)
    Transgenic mice for Challenge test: 5 female and 20 male B6.Cg-Tg(K18-hACE2)2Prlmn/J transgenic mice at 6 weeks of age were purchased from The Jackson laboratories.
    B6.Cg-Tg(K18-hACE2)2Prlmn/J
    suggested: None
    25 days following vaccination, K18-hACE2 mice were intranasally infected with a 3×104 TCID50 dose of infective SARS-CoV-2 in 30μl solution in Biosafety level cabin II in Transgenic Animal Biosafety level 3 laboratory (ABSL-3) of AAALAC International accredited
    K18-hACE2
    suggested: RRID:IMSR_GPT:T037657)
    Software and Algorithms
    SentencesResources
    The entire system was controlled by Xcalibur 4.0 software (Thermo Fisher Scientific, USA)
    Xcalibur
    suggested: (Thermo Xcalibur, RRID:SCR_014593)
    The minimum number of peptides identified for each protein was considered to be 1 and obtained data were searched in the Uniprot/Swissprot database.
    Uniprot/Swissprot
    suggested: None
    Statistical analyses were performed using the Graphpad Prism and SPSS Statistics software.
    Graphpad Prism
    suggested: (GraphPad Prism, RRID:SCR_002798)
    SPSS
    suggested: (SPSS, RRID:SCR_002865)

    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 found bar graphs of continuous data. We recommend replacing bar graphs with more informative graphics, as many different datasets can lead to the same bar graph. The actual data may suggest different conclusions from the summary statistics. For more information, please see Weissgerber et al (2015).

    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.

  5. Version published to 10.1101/2020.10.28.356667v1 on bioRxiv