npj Vaccines (Jun 2023)

Lyophilization to enable distribution of ChAdOx1 and ChAdOx2 adenovirus-vectored vaccines without refrigeration

  • Cheng Zhang,
  • Adam Berg,
  • Carina C. D. Joe,
  • Paul A. Dalby,
  • Alexander D. Douglas

DOI
https://doi.org/10.1038/s41541-023-00674-2
Journal volume & issue
Vol. 8, no. 1
pp. 1 – 9

Abstract

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Abstract Distribution of vaccines which require refrigerated or frozen storage can be challenging and expensive. The adenovirus vector platform has been widely used for COVID-19 vaccines while several further candidate vaccines using the platform are in clinical development. In current liquid formulations, adenoviruses require distribution at 2–8 °C. The development of formulations suitable for ambient temperature distribution would be advantageous. Previous peer-reviewed reports of adenovirus lyophilization are relatively limited. Here, we report the development of a formulation and process for lyophilization of simian adenovirus-vectored vaccines based on the ChAdOx1 platform. We describe the iterative selection of excipients using a design of experiments approach, and iterative cycle improvement to achieve both preservation of potency and satisfactory cake appearance. The resulting method achieved in-process infectivity titre loss of around 50%. After drying, there was negligible further loss over a month at 30 °C. Around 30% of the predrying infectivity remained after a month at 45 °C. This performance is likely to be suitable for ‘last leg’ distribution at ambient temperature. This work may also facilitate the development of other product presentations using dried simian adenovirus-vectored vaccines.