The pharmaceutical company AstraZeneca has announced that it has resumed its coronavirus vaccine trial in the UK after suspending it six days ago over potential safety issues but that its trials in the US and other countries were still on hold, reports The New York Times.
The news came the same day that a competitor, Pfizer, said it was expanding the trial of its coronavirus vaccine to 44,000 people – a big increase from its previous goal of 30,000 – in an effort to recruit a more diverse group of participants and potentially cut down the time needed to get results from the trial.
The NYT reports that together, the developments raised new questions about when a vaccine might be available and showed just how unpredictable vaccine development can be, even as the world is desperately waiting for something that can bring an end to the pandemic.
The report says both companies’ announcements lacked crucial details, prompting criticism that they were not being open enough about the data they’re collecting. AstraZeneca did not offer any information to support the decision to partially resume trials and would not give any details about the illness of a patient that had led to the suspension. Pfizer did not explain how it would determine the effectiveness of the vaccine in its expanded trials.
Dr Eric Topol, a professor of molecular medicine at the Scripps Research Institute in San Diego and an expert on clinical trials, found both announcements worrisome, contending that the companies were withholding crucial information. “The public has a right to know what’s going on,” he is quoted in the NYT as saying. “The future depends on it.”
AstraZeneca and Pfizer are among the three companies that are currently testing their candidates in late-stage clinical trials in the US – Moderna is the third – in a record-setting race to develop a coronavirus vaccine. All three have said they expect to have a vaccine ready – at least for high-priority groups – before the end of the year.
In announcing that it had resumed the trial in the UK, AstraZeneca said that an outside panel of experts had reviewed the case and had told the British government’s Medicines and Healthcare Products Regulatory Authority that the trials could be safely resumed. The authority agreed, giving the green light to start again.
Michele Meixell, a spokeswoman for AstraZeneca, said that the company could not disclose any further medical information about the sick volunteer. “All trial investigators and participants will be updated with the relevant information and disclosed on global clinical registries, according to the clinical trial and regulatory standards,” she said in an email.
According to the NYT, Meixell did not say when she expected the trials in other countries to restart. “AstraZeneca will continue to work with health authorities across the world and be guided as to when other clinical trials can resume,” she said.
Oxford University said that the UK Medicines and Healthcare Products Regulatory Agency (MHRA) had recommended that its trials resume after an independent committee review of safety data triggered a pause last week.
The Guardian quotes the university as saying: “Globally some 18,000 individuals have received study vaccines as part of the trial. In large trials such as this, it is expected that some participants will become unwell and every case must be evaluated to ensure careful assessment of safety.”
Experts say such halts are common in vaccine trials. But, The Guardian says, interruption to the Oxford study fuelled concerns about whether such trials were proceeding too quickly. It was the second time that trials of the vaccine, which began in April, had been paused.
AstraZeneca’s CEO, Pascal Soriot, said that the independent committee was reviewing whether the participant’s illness had been caused by the vaccine or was unrelated. “We cannot disclose medical information about the illness for reasons of participant confidentiality,” the university explained. “We are committed to the safety of our participants and the highest standards of conduct in our studies and will continue to monitor safety closely.”
In addition to trials in the UK, studies are being carried out in the US, Brazil and South Africa. Vaccine developers are under acute political pressure to secure a breakthrough.
The University of the Witwatersrand (Wits) announced last week that it would pause its coronavirus vaccine trial owing to the medical event in a volunteer in the UK. It said in a Polity report that the trial would be paused as part of standard regulatory procedure for the safety of participants. The details of the medical event that the participant in the UK experienced may not be divulged as this contravenes patient confidentiality.
Wits announced South Africa and Africa’s first COVID-19 vaccine trial, the so-called “Oxford trial”, in June.
Vaccines and Infectious Diseases Analytics Research Unit executive director Professor Shabir Madhi, who is leading the Ox1nCov19 trial in South Africa, said pausing vaccination to review safety is evidence of the application of sound clinical practice and demonstrates the rigour of the independent oversight process under which this trial is being conducted.
“Assessing the safety of the vaccine are the reasons why studies such as these are essential in South Africa before there is widespread use of the vaccine,” said Madhi.
The Independent Data and Safety Monitoring Committee (DSMC) has recommended that all studies which they are overseeing pause further vaccination. This will allow the DSMC to undertake a thorough review of the case in the UK.
Madhi said all sites in the country have paused further vaccination. “Trial volunteers who are scheduled to receive either a first or second dose of the vaccine have been notified and we are in regular communication with them as to when vaccination will resume. This decision will be based on the DSMC’s recommendation. Ensuring the safety of all our study participants is our highest priority,” says Madhi.
Full report in The New York Times
Full report in The Guardian
Full Polity report