AstraZeneca halts coronavirus vaccine trial after volunteer falls ill
Pharmaceutical giant AstraZeneca announced on Tuesday that it was halting late-stage trials of the coronavirus vaccine, developed in collaboration with the University of Oxford, after a volunteer fell ill. The company is conducting late-stage trials at a number of sites, including the United Kingdom, from where the "suspected serious adverse reaction" to the vaccine was reported. A spokesperson from AstraZeneca confirmed the news.
Matter is being investigated, integrity of trials important: AstraZeneca
Confirming that trials have been put on hold, AstraZeneca said its "standard review process triggered a pause to vaccination to allow the review of safety data." The company said this routine action was bound to happen whenever "there's a potentially unexplained illness in one of the trials." The matter was being investigated, AstraZeneca said, adding that it won't compromise on the integrity of trials.
AstraZeneca working towards mitigating the impact on vaccine timeline
"In large trials, illnesses will happen by chance but must be independently reviewed to check this carefully. We are working to expedite the review of the single event to minimize any potential impact on the trial timeline. We are committed to the safety of our participants," the statement added.
Trial was halted due to "abundance of caution"
While details about the severity of the illness were unclear, a source told Statnews that people working on the vaccine were told to hold trials due to "an abundance of caution." Another person in the know said this development would directly affect other vaccine trials of AstraZeneca, as well as clinical trials of other potential vaccines, developed by different companies.
The vaccine had showed promising results in early stages
A pause in clinical trials is not uncommon but considering that a battered world is pinning hopes on a vaccine, the latest development serves as a setback. The vaccine, dubbed AZD1222, had shown commendable results in the early stages with developers announcing that it provides double protection against the highly contagious coronavirus. Besides antibodies, the vaccine also generated virus-attacking T-cells in candidates, said reports.
Candidates reported mild side-effects in early stages as well
Notably, AstraZeneca's vaccine uses adenovirus, which has a gene that makes the spike protein of the coronavirus. The adenovirus is intended to generate protection against the virus. To recall, in the early trials, several candidates had complained of moderate side effects like fever, headaches, muscle pain, et al. However, those were minor side effects, and not entirely uncommon.
Illness could be a result of medical history, feels expert
Paul Offit, an expert with the United States' Food and Drug Administration, said the UK-based company has to determine whether the illness was caused due to a reaction to the vaccine or was associated with the person's medical history. "It all depends on what the problem was," he told Financial Times, reminding that in early stages more than 50% of candidates had a fever.
AstraZeneca's shares dipped, meanwhile, its rivals recorded gains
As the news about the setback surfaced, AstraZeneca's shares dipped more than 8% in after-hours US trading, while those of Moderna Inc. and Pfizer Inc. — which are also developing a coronavirus vaccine — swelled by nearly 4% and 1% respectively. While nine vaccine candidates have entered Phase-3 trials, AstraZeneca's is the first one to be put on hold.