AstraZeneca reports that clinical trials for its COVID-19 vaccine, AZD1222, have resumed in the UK following confirmation by the UK pharmaceutical regulatory authority, the Medicines Health Regulatory Authority (MHRA), that it was safe to do so following a temporary pause of trials.

Earlier this month (September 2020), AstraZeneca reported that it had temporarily paused its clinical trials for its COVID-19 vaccine, AZD1222, to allow an independent committee to review the safety data of a single event of an unexplained illness that occurred in a Phase III trial in the UK. The company said the incident was found during standard review of the trial

“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,” said AstraZeneca in a September 12, 2020 statement. “The UK committee has concluded its investigations and recommended to the MHRA that trials in the UK are safe to resume.”

Prior to the voluntary trial pause, clinical development of AZD1222 was progressing globally with late-stage clinical trials ongoing in the UK, Brazil, and South Africa, with trials planned to start in Japan and Russia (as reported by the company on August 31, 2020). These trials, together with a US Phase III clinical trial, were planned to enroll up to 50,000 participants globally. Results from the late-stage trials were anticipated later this year (2020), depending on the rate of infection within the clinical trial communities.

AZD1222 was co-invented by the University of Oxford and its spin-out company, Vaccitech, and licensed to AstraZeneca. It 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 protein. After vaccination, the surface spike protein is produced, priming the immune system to attack the SARS-CoV-2 virus if it later infects the body.

AstraZeneca says that it and the University of Oxford, as the trial sponsor, cannot disclose further medical information and that all trial investigators and participants will be updated with the relevant information that will be disclosed on global clinical registries according to the clinical trial and regulatory standards.

Source: AstraZeneca