Just under a week after it stopped its key phase 3 pandemic vaccine test, AstraZeneca and the University of Oxford have been given the green light to restart in the U.K.
Announced over the weekend, the U.K. Big Pharma said its vaccine, known as AZD1222, “has resumed in the U.K. following confirmation by the Medicines Health Regulatory Authority (MHRA) that it was safe to do so.”
It was halted at the start of last week over a serious safety concern. AstraZeneca was, and still is, keeping mum on the exact nature of what happened, but according to a New York Times report that cited a person familiar with the situation, a participant based in the U.K. was found to have transverse myelitis, an inflammatory syndrome that affects the spinal cord and is often sparked by viral infections.
In its statement over the weekend, AZ said it “cannot disclose further medical information” about why it halted, but added, “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 World Health Organization has cited AZD1222, a replication-deficient chimpanzee viral vector based on a weakened version of a common cold virus that contains the genetic material of the SARS-CoV-2 virus spike protein, as a leading contender in the race for a vaccine.
Around 18,000 participants have had AZD1222 as part of the trial, AZ said.
While AZ and Oxford have been highlighted as race leaders, so too have Pfizer and BioNTech, which said they now want to boost their phase 2/3 trial for one of their five mRNA vaccines, BNT162b2, from around 30,000 to 44,000.
Also over the weekend, the companies said they have asked the FDA for the extra participants in order to include a broader patient population and with plans to include adolescents as young as 16 and people with chronic, stable HIV (human immunodeficiency viruses), hepatitis C or hepatitis B infection to “provide additional safety and efficacy data.”
It said it’s on track to hit its original target of 30,000 patients this week; despite wanting more people, Pfizer said in a statement that it was still on course to deliver data by the end of next month.