A Covid-19 vaccine developed by the University of Oxford and AstraZeneca Plc prevented a majority of people from getting the disease in a large trial, another promising development in the quest to end the pandemic, and the rollout could begin next month.
The vaccine stopped an average of 70% of participants from falling ill, an early analysis of the data show. The effectiveness rose to 90% for one of two regimens, using half a dose followed by a full one later, close to the high bar set by Pfizer Inc. and Moderna Inc.
Astra and Oxford officials said they’re preparing to submit the findings to regulators and don’t expect the different outcomes in the study to affect the process. The U.S. could potentially take longer to sign off because a clinical trial in that country will need more time before it delivers results.
“Our goal was to make sure we can have a vaccine that is accessible everywhere,” Andrew Pollard, who is leading the Astra-Oxford trials, said Monday at a press briefing. “I think we have actually managed to do that.”
The results, based on trials in the U.K. and Brazil, were reviewed after 131 participants contracted Covid-19. The full two doses showed an efficacy of 62%. Among those who received the vaccine, there were no severe cases and no participants were hospitalized. The group is planning to submit the data for peer review in the next 24 hours.
Astra shares dropped as much as 3.2% in London, losing ground after SVB Leerink analyst Geoffrey Porges said the vaccine would “never be licensed” in the U.S. because of questions around the data. Highlighting the 90% efficacy in a subset of trial participants was an effort to “embellish” the results, he said.
“The suggestion by the inventors that the small sample given the lower priming dose was evidence of superior efficacy only brings discredit to the program,” Porges said in a report.
Astra didn’t immediately comment on the note. The stock is still up about 30% since mid-March, but Moderna and Pfizer shares surged when they reported their results.
The larger U.S. Astra trial, which could be key for approval there, has injected about 10,500 people with both doses. Mene Pangalos, Astra’s head of biopharma research, told reporters the team is planning to talk to the U.S. Food and Drug Administration immediately and hopes to have another arm administering the half dose-full dose regimen starting within weeks.
“That scenario is possible,” that other regulators could move before the U.S., he said. “We need to share the data with the FDA, which we will do very quickly, and then we will work out what the most appropriate steps are.”