AstraZeneca COVID-19 vaccine trial resumed in the UK after safety evaluation


12 September 2020

AstraZeneca (Oxford, UK) have resumed the Phase III trial of their AZD1222 vaccine after the conclusion of an investigation by the Medicines & Healthcare products Regulatory Agency (MHRA; London, UK) into the safety of the vaccine. 

Following the voluntary pause in the global vaccine trial that was put in place last week, an independent review into the safety of the trial was triggered. The review was conducted by independent and international committees and regulators. The outcome of the investigation is that the trial has been determined safe to continue in the UK.

AstraZeneca have maintained throughout that they are fully committed to the safety of all patients in the trial and are vigoriously following the guidelines involved in running a clinical trial. Health authorities across the world are still working to reach a reccomdation for the recomencement of the other clinical trials.

AstarZeneca continue to work towards the development of a safe vaccine that can be broadly distributed for use against COVID-19.


8 Septmember 2020

AstraZeneca (Oxford, UK) and the University of Oxford (UK) have recently started a Phase III clinical trial in the USA to test the safety, efficacy and immunogenicity of the AZD1222 vaccine in the prevention of COVID-19.

The trial has recruited nearly 30,000 patients thus far, including adults from a diverse range of ethnic and geographic groups as well as those with varied health status such as those living with HIV. Centers outside the USA are also recruiting in Chile, Peru, Brazil and the UK.

In early September, AstraZeneca halted their global trials of the ChAdOx1 nCoV-19 vaccine due an adverse reaction experienced by a patient in the UK. The halt is described as a voluntary, routine pause in testing while AstraZeneca conducts a safety review of the case to determine whether the reaction was caused by the vaccine or if it was unrelated.

AstraZeneca notes that the pause is a routine action taken whenever there is a potentially unexplained illness in one of the trials, allowing it be be investigated whilst ensuring that the integrity of the trials is maintained.

The volunteer has a suspected diagnosis of an inflammatory syndrome, – transverse myelitis – which affects the spinal cord and is often triggered by viral infections. Steroids can be used to treat the condition. Currently, due to the timing of the development of the syndrome, the vaccine company must determine the cause before continuing with the trial.

Pascal Soriot, Chief Executive Officer at AstraZeneca, stated: “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.”

In July of this year, the company published a paper in The Lancet, which reported the initial results from the Phase I/II vaccine trials. The initial testing phases demonstrated a good safety profile with only mild to moderate side effects experienced, allowing the progression into Phase III trials to go ahead.

Large-scale late-stage vaccine trials are necessary to determine the effectiveness of the vaccine in producing an immune response and also in highlighting any uncommon or severe side effects that may only arise once thousands of people have received the vaccine.

Halting the AstraZeneca trial until the cause of this reaction can be determined is important while we wait to see whether the trial can continue.



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