Process- and product-related impurities in the ChAdOx1 nCov-19 vaccine
Abstract
ChAdOx1 nCov-19 and Ad26.COV2.S are approved vaccines inducing protective immunity against SARS-CoV-2 infection in humans by expressing the Spike protein of SARS-CoV-2. We analyzed protein content and protein composition of ChAdOx1 nCov-19 and Ad26.COV2.S by biochemical methods and by mass-spectrometry. Four out of four tested lots of ChAdOx1 nCoV-19 contained significantly higher than expected levels of host cell proteins (HCPs) and of free viral proteins. The most abundant contaminating HCPs belonged to the heat-shock protein (HSP) and cytoskeletal protein families. The HCP content exceeded the 400 ng specification limit per vaccine dose, as set by the European Medicines Agency (EMA) for this vaccine, by at least 25-fold and the manufacturer's batch-release data in some of the lots by several hundred-fold. In contrast, three tested lots of the Ad26.COV2.S vaccine contained only very low amounts of HCPs. As shown for Ad26.COV2.S production of clinical grade adenovirus vaccines of high purity is feasible at an industrial scale. Correspondingly, purification procedures of the ChAdOx1 nCov-19 vaccine should be modified to remove protein impurities as good as possible. Our data also indicate that standard quality assays, as they are used in the manufacturing of proteins, have to be adapted for vectored vaccines.
Data availability
All data supporting the findings of this study are available within this paper. An overview of protein identifications and quantifications based on LC/MS analysis is shown in the source data (Fig. 2 - Source Data 1, Fig. 3 - Source Data 1, and Fig. 4 - Source Data 1).LC/MS-raw data and search results have been deposited at the Mass Spectrometry Interactive Virtual Environment(MassIVE; https://massive.ucsd.edu/ProteoSAFe/static/massive.jsp) data lake and are publicly available under ID MSV000089634.
Article and author information
Author details
Funding
German Federal Ministry of Education and Research and Federal States of Germany Grant Innovative Hochschule"" (FKZ3IHS024D)
- Lea Krutzke
- Reinhild Rösler
- Ellen Allmendinger
- Tatjana Engler
- Sebastian Wiese
- Stefan Kochanek
German Research Foundation (SFB1074)
- Lea Krutzke
- Reinhild Rösler
- Ellen Allmendinger
- Tatjana Engler
- Sebastian Wiese
- Stefan Kochanek
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: Animal experiments were approved by the Animal Care Commission of the Government Baden-Württemberg. Reference number: TVA #1508.
Reviewing Editor
- Sara L Sawyer, University of Colorado Boulder, United States
Publication history
- Preprint posted: May 4, 2021 (view preprint)
- Received: March 9, 2022
- Accepted: July 3, 2022
- Accepted Manuscript published: July 4, 2022 (version 1)
- Version of Record published: July 25, 2022 (version 2)
Copyright
© 2022, Krutzke et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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