AstraZeneca has paused all clinical trials of the Covid-19 vaccine it is developing with Oxford university after a participant in the UK arm of the study suffered a suspected serious adverse reaction.
The UK-based drugmaker voluntarily put the trial on hold after the discovery of the sick participant. AstraZeneca said that it was working to review the event to ensure it would not result in a significant delay to the study.
AstraZeneca had been on track to become one of the first drugmakers to deliver results from a large trial of a Covid-19 vaccine in a race where many pharmaceutical companies are moving at breakneck speed. The White House has considered fast-tracking the company’s inoculation ahead of the US presidential election, according to people familiar with the matter.
“As part of the ongoing randomised, controlled global trials of the Oxford coronavirus vaccine, our standard review process triggered a pause to vaccination to allow review of safety data,” a spokesman said.
“This is a routine action which has to happen whenever there is a potentially unexplained illness in one of the trials, while it is investigated, ensuring we maintain the integrity of the trials,” he added. “In large trials, illnesses will happen by chance but must be independently reviewed to check this carefully.”
Shares of the UK-based pharmaceutical company dropped more than 6 per cent in after-hours trading in New York after trade publication STAT first reported that the trial had to be stopped.
It is not unusual for clinical trials to be paused. But in the most scrutinised vaccine development process ever, any sign of potentially negative side-effects could be seen as scuppering hopes for rapid relief from the pandemic.
Even if AstraZeneca’s vaccine is eventually approved, concerns about side-effects may still deter people from getting vaccinated.
Experts have already raised concerns that approval of a vaccine could be rushed as the process becomes politicised, although both the pharmaceutical companies and the US Food and Drug Administration have insisted an inoculation would only be authorised based on solid science.
Joe Biden, the Democratic presidential candidate, and Kamala Harris, his vice-presidential nominee, called upon the Trump administration on Tuesday to ensure that “politics will play no role in the approval and distribution of a safe and effective Covid-19 vaccine”.
AstraZeneca is commercialising the vaccine created by researchers at the University of Oxford under a deal signed in April. To speed up the process, the drugmaker has begun manufacturing the jab before the trials are complete or the vaccine is approved.
The partnership — which has already received over $1bn in funding from the US Biomedical Advanced Research and Development Agency — has agreed to deliver over 300m doses to the US government.
The UK has ordered 30m of AstraZeneca’s potential vaccine. Matt Hancock, the UK health secretary, said this week it would “most likely” be available in early 2021.
Data from the vaccine’s earliest trial looked promising, producing robust immune responses and only mild side-effects, such as those that can be treated with over-the-counter painkillers.
The initial phase two/three study did not include sites within the US but late last month the phase 3 trial, which will have 30,000 participants, began enrolling in the US.
The trial was paused voluntarily by the drugmaker. Such decisions are normally made by an independent monitoring committee.