Longer wait for coronavirus vaccine

Drug giant Astra Zeneca announced on September 9 that it had paused global trials of its coronavirus vaccine because of an "unexplained illness" in one of the volunteers. No doubt, it is a standard precaution in vaccine trials that is meant to ensure experimental vaccines don't cause serious reactions among participants.

The company is testing its vaccine, developed by Britain's University of Oxford, in the United States as well as the UK, Latin America, Asia, Europe and Africa.

Of course, when large trials happen, illnesses would happen. But, it is important that it is checked and rechecked carefully and properly. The review of the 'single event' is bound to take place to minimise any potential impact on the trial timeline. The nature of the adverse reaction and when it happened were not immediately known, though the participant is expected to recover. Researchers have been told the hold was placed on the trial out of "an abundance of caution."

The finding is having an impact on other AstraZeneca vaccine trials underway — as well as on the clinical trials being conducted by other vaccine manufacturers. It's unclear how long AstraZeneca's might last. But the progress of the company's trial — and those of all Covid-19 vaccines in development — are being closely watched given the pressing need for new ways to curb the global pandemic.

There are currently nine vaccine candidates in Phase 3 trials. AstraZeneca's is the first Phase 3 Covid-19 vaccine trial known to have been put on hold. AstraZeneca is unlikely to share the details of the "unexplained illness" until it thoroughly investigates if it was indeed the vaccine – or any other factor – that triggered it. Its shares have tanked by 10 percent since the announcement because this revelation is bound to raise questions about the safety of its vaccine and nearly makes certain that the Oxford vaccine won't be the first in the world to be approved by drug regulators.

The Oxford vaccine has been widely seen as one of the leading global candidates against the coronavirus, and the suspension of the trial dims prospects for a potential year-end rollout its lead developer had signaled earlier. The mad rush to procure a vaccine that had not been completely tested has hit a major hurdle now. After promising early results in smaller Phase 1 and 2 trials, AstraZeneca's vaccine moved to a large-scale trial in the United States in late August.

Late-stage trials for the drug had already begun in the U.K., Brazil, and South Africa. While it's not immediately clear what side effects presented in the single participant, during Phase 1/2 trails, 60 per cent of 1,000 participants given the drug experienced mild to moderate side effects, including fever, headaches, muscle pain and injection site reactions, according to a study published in July.

As for India, the Serum Institute of India is conducting the clinical trials - a combined Phase 2 and Phase 3 - which is covering 1,600 participants and the product here is known as Covishield. Well, with this happening now, there is little hope that the country or the world could have an early solution to the COVID-19 problem.