AstraZeneca Resumes U.K. Portion of COVID-19 Vaccine Study Following Safety Review


AstraZeneca resumed its vaccine testing in the United Kingdom following confirmation from the Medicines Health Regulatory Authority (MHRA) that it was safe to do so.

The trial was briefly paused for safety concerns after a participant in the Phase III COVID-19 study was hospitalized with suspicion of having developed a serious spinal inflammatory disorder called transverse myelitis. AstraZeneca confirmed the patient had been dosed with the company’s experimental coronavirus vaccine candidate AZD1222 and paused the study. The patient was set to undergo some additional tests to determine whether or not the vaccine could have caused the disorder, an inflammation of a part of the spinal cord that can lead to pain, muscle weakness, paralysis, sensory problems or bladder and bowel dysfunction. According to the Mayo Clinic, transverse myelitis can be caused by infections and immune system disorders.

Following her hospitalization, AstraZeneca paused its Phase III global vaccine study, but with the nod from the MHRA, restarted the program in the U.K. on Saturday after the committee concluded its investigations and recommended the trial resumes. The study in the United States, which was launched last month and is expected to recruit up to 30,000 patients, remains paused at this time.

In its brief announcement Saturday, AstraZeneca and its development partner the University of Oxford, said they could not disclose any additional medical information at the time. 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, the company said. AstraZeneca said it will expedite the review of the patient’s illness to minimize any potential impact on the timeline of the trial.

With the resumption of the U.K. portion of the trial, AstraZeneca could remain on target for a potential readout of the Phase III study before the end of the year. Chief Executive Officer Pascal Soriot suggested that last week when the study was halted.

AstraZeneca’s COVID-19 vaccine candidate AZD1222 is a viral vector-based, weakened version of adenovirus containing the genetic material of SARS-CoV-2 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. In July, the company published positive Phase I data from its vaccine candidate that showed the preventative medication generated both neutralizing antibodies and immune T-cells that target the virus that causes COVID-19.

If the vaccine makes it through regulatory trials, AstraZeneca plans to manufacture two billion doses of its vaccine, with 400 million slated for the U.S. and UK, and one billion allotted for low- and middle-income countries.

The trial pause this week, which was the second since July, was made in order to ensure the medication, which could be provided to hundreds of millions of people, is not only effective against the virus, but also safe. The trial was paused on the same day that AstraZeneca and eight other vaccine manufacturers signed a pledge to allow science and not political expediency to drive the development and potential regulatory authorization of the medication. The pledge was announced following rumors the U.S Food and Drug Administration could grant an Emergency Use Authorization to one of the vaccine candidates being supported by Operation Warp Speed due to political pressure from the White House.

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