Haematologica (Jan 2022)

Comparative analysis of ChAdOx1 nCoV-19 and Ad26.COV2.S SARS-CoV-2 vector vaccines

  • Stephan Michalik,
  • Florian Siegerist,
  • Raghavendra Palankar,
  • Kati Franzke,
  • Maximilian Schindler,
  • Alexander Reder,
  • Ulrike Seifert,
  • Clemens Cammann,
  • Jan Wesche,
  • Leif Steil,
  • Christian Hentschker,
  • Manuela Gesell-Salazar,
  • Emil Reisinger,
  • Martin Beer,
  • Nicole Endlich,
  • Andreas Greinacher,
  • Uwe Völker

DOI
https://doi.org/10.3324/haematol.2021.280154
Journal volume & issue
Vol. 107, no. 4

Abstract

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Vector-based SARS-CoV-2 vaccines have been associated with vaccine- induced thrombosis with thrombocytopenia syndrome (VITT/TTS), but the causative factors are still unresolved. We comprehensively analyzed the ChAdOx1 nCoV-19 (AstraZeneca) and Ad26.COV2.S (Johnson and Johnson) vaccines. ChAdOx1 nCoV-19 contains significant amounts of host cell protein impurities, including functionally active proteasomes, and adenoviral proteins. A much smaller amount of impurities was found in Ad26.COV2.S. Platelet factor 4 formed complexes with ChAdOx1 nCoV-19 constituents, but not with purified virions from ChAdOx1 nCoV-19 or with Ad26.COV2.S. Vascular hyperpermeability was induced by ChAdOx nCoV-19 but not by Ad26.COV2.S. These differences in impurities together with EDTAinduced capillary leakage might contribute to the higher incidence rate of VITT associated with ChAdOx1 nCoV-19 compared to Ad26.COV2.S.