Clinical trial for AstraZeneca Oxford COVID-19 vaccine candidate to resume

The randomised, controlled clinical trial to test the COVID-19 vaccine candidate, developed by the University of Oxford, UK, and AstraZeneca, has now resumed. Last week, the trial was put on hold following an unexplained illness in one of the participants of the trial. 

The study of the AZD1222 COVID-19 vaccine will now continue after confirmation from the UK Medicines and Healthcare products Regulatory Agency (MHRA) that it was safe to do so.

AZD1222 uses a replication-deficient chimpanzee viral vector based on a weakened version of a common cold virus (adenovirus) that causes infections in chimpanzees and contains the genetic material of the SARS-CoV-2 virus Spike (S) protein. After vaccination, the surface S protein is produced, priming the immune system to attack the SARS-CoV-2 virus if it later infects the body.

On 6 September, the standard review process triggered a voluntary pause to vaccination across all global trials to allow review of safety data by independent committees and international regulators. The UK committee has concluded its investigations and recommended to the MHRA that trials in the UK are safe to resume.

Pascal Soriot, Chief Executive Officer of AstraZeneca, said: “At AstraZeneca we put science, safety and the interests of society at the heart of our work. This temporary pause is living proof that we follow those principles while a single event at one of our trial sites is assessed by a committee of independent experts. We will be guided by this committee as to when the trials could restart, so that we can continue our work at the earliest opportunity to provide this vaccine broadly, equitably and at no profit during this pandemic.”

The University of Oxford and AstraZeneca say that all trial investigators and participants will be updated with the relevant information and this will be disclosed on global clinical registries, according to the clinical trial and regulatory standards.

AstraZeneca emphasises it will continue to work with health authorities across the world and be guided as to when other clinical trials can resume to provide the vaccine broadly, equitably and at no profit during this pandemic.