AZD1222 (ChAdOx1 nCov-19): A Single-Dose biodistribution study in mice

Biodistribution studies of adenovirus-based vaccines support their clinical development by evaluating their spread and persistence following in vivo administration. AZD1222 (ChAdox1 nCov-19) is a replication-deficient non-human adenovirus-vectored vaccine for coronavirus disease 2019. In this nonclinical study, the biodistribution of AZD1222 was assessed in mice for 29 days following intramuscular injection. Results show that AZD1222 was safe and well tolerated, with a spread that was largely confined to administration sites and the proximal sciatic nerve, with low levels observed in sites that are involved in rapid clearance of particulates by the reticuloendothelial system. Accordingly, levels of AZD1222 decreased from Day 2 to Day 29, indicating clearance. There were no quantifiable levels of AZD1222 in the blood, brain, spinal cord, and reproductive tissue, suggesting a lack of widespread or long-term distribution of AZD1222 vector DNA throughout the body following its administration. (c) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Biodistribution studies showed that AZD1222 vaccine had limited spread in mice, mainly confined to the administration sites and the proximal sciatic nerve, with low levels observed in sites involved in rapid clearance. The levels of AZD1222 decreased from Day 2 to Day 29, indicating clearance. No measurable levels of AZD1222 were found in the blood, brain, spinal cord, and reproductive tissue, suggesting a lack of widespread or long-term distribution of AZD1222 vector DNA in the body.