AstraZeneca (LON:AZN) and its collaborators at the University of Oxford have published data related to their ChAdOx1 nCoV-19 vaccine against the novel coronavirus in the Lancet, becoming the first vaccine developers to publish full Phase 3 results in a peer-reviewed journal.
The efficacy rate of 62.1% achieved in clinical trial participants receiving two full doses of the vaccine exceeds FDA’s baseline requirement of 50% efficacy. But the figure is considerably less than the 90% efficacy the COVID-19 vaccines from Pfizer (NYSE:PFE) and Moderna (NYSE:MRNA) promise, both of which also require two doses.
The overall efficacy was higher — approximately 90% — in vaccine recipients who received a half dose followed by a full dose. The low-dose/standard-dose regimen, however, was 59% effective at protecting against asymptomatic COVID-19 infection.
Nevertheless, the data “provide some hope that COVID-19 vaccines might be able to interrupt some asymptomatic transmission,” the study authors concluded.
The vaccine was mostly well-tolerated in patients, with 175 experiencing severe adverse events out of a patient pool of 11,636. Of that total, 84 were in the vaccine group. The remainder received a placebo.
At one point during the Phase 3 study, the company halted trials around the world after a U.K. participant fell ill with neurological symptoms. The company later concluded that that adverse event was unrelated to the vaccine.
But according to the New York Times, AstraZeneca initially failed to disclose that news to the FDA, potentially damaging its relationship with regulators.
The vaccine, however, offers advantages in terms of its low cost and simple storage requirements.
Regulatory agencies in the U.K., India and other countries could authorize emergency use of the vaccine in the near future.
Filed Under: clinical trials, Drug Discovery, Uncategorized