On Tuesday, the global pharma major AstraZeneca announced that it is putting a halt to the ongoing clinical trials for the COVID-19 vaccine, after a volunteer developed inflammation in her spinal cord. The Swedish-British company, which is developing the vaccine in collaboration with Oxford University, has confirmed that the volunteer from the UK, who developed the adverse reaction, was administered the vaccine, not the placebo. It has said that an independent panel will investigate what went wrong. The pharma company’s Indian collaborator, the Pune-based Serum Institute of India, has also put the vaccine’s trials on hold. It is too early to say if these suspensions amount to a setback in the global efforts to develop a preventive against the novel coronavirus. But there are enough reasons to suggest that there is no need to jump to pessimistic conclusions. The review should, instead, be seen as a part of the rigorous scrutiny that vaccine candidates must go through.
Adverse events during vaccine tests are not rare — in 2014, work on the Ebola vaccine was temporarily stopped because some volunteers suffered arthritis. Unlike the first two phases of the trials, in which healthy adults are administered the vaccine, Phase 3 trials involve a large number of participants some of whom could have an underlying medical condition — Oxford AstraZeneca’s UK trials reportedly include volunteers over 70 years of age, which increases the risk of adverse events. The volunteer who fell ill after being administered the vaccine candidate developed symptoms of transverse myelitis — a rare neurological disorder that is treated with steroids, though serious cases are known to leave lasting disabilities. There is also the possibility that the volunteer’s illness has no direct connection with the vaccine — in fact, in July, preliminary trials of the Oxford AstraZeneca vaccine were temporarily stopped because a volunteer developed neurological symptoms, later found unrelated to the jab. The review process will tease out whether the latest adverse reaction was coincident with the trial or caused by it.
The pause in the Oxford-AstraZeneca trials comes at a time when there is a virtual scramble to develop a vaccine against the novel coronavirus. There are concerns in the US that the country’s regulatory agencies could be pressured to approve a vaccine before the presidential elections in November. US President Donald Trump has repeatedly suggested that the country’s vaccination drive could begin in late October. The adverse event at the Oxford-AstraZeneca trials — and the vaccine developers’ response — is a sobering reminder that vaccine development is not about winning a race. Science must be followed and due procedures should take their course.
