Latest results put Oxford–AstraZeneca COVID vaccine back on track


The Oxford-AstraZeneca vaccine’s rollercoaster ride of a week might be coming to a welcome end. A key phase III clinical trial found the vaccine to be 76% effective at preventing COVID-19, the company announced on 25 March, two days after it was accused of misrepresenting interim results that reported a slightly higher efficacy figure of 79%.

Scientists hope the kerfuffle will not cause lasting damage to the vaccine’s long-term reputation, which could be bolstered by scrutiny — and likely approval — by US drug regulators.

“Overall it’s a win for the world,” says Ann Falsey, a vaccine scientist at the University of Rochester, New York and an investigator on the trial who co-developed its protocol. “The final story is the results for the final analysis are great. They look very similar to the interim analysis.”

The difference between 76% and 79% efficacy is “tiny, and to be expected with the number of cases analysed”, said Peter English, a retired consultant in communicable disease control, in a statement to the UK Science Media Centre.