AstraZeneca Confirms Vaccine Efficacy with Phase III Primary Analysis

AstraZeneca has released the results of its primary analysis of the Phase III trial data evaluating its COVID-19 vaccine, AZD1222, in a March 25, 2021 press release. The analysis confirms vaccine efficacy is consistent with the interim analysis announced earlier in the week on March 22, 2021.

The results of the primary analysis have been presented to the independent Data Safety Monitoring Board (DSMB) and will form the basis for a regulatory submission for emergency use authorization to FDA. An accrued total of 190 symptomatic cases of COVID-19 from the 32,449 participants were included in the primary efficacy analysis, which is an additional 49 cases compared with the interim analysis.

Based on the data, vaccine efficacy for the prevention of symptomatic COVID-19 was found to be 76% when two doses were administered four weeks apart. The results of the primary analysis were comparable across all age groups, with increased efficacy of 85% in those aged 65 years and older. Additionally, the vaccine was found to be 100% effective for a secondary endpoint—the prevention of severe or critical disease and hospitalization. No safety concerns were identified in relation to the vaccine, which was well-tolerated by the participants.

“The primary analysis is consistent with our previously released interim analysis, and confirms that our COVID-19 vaccine is highly effective in adults, including those aged 65 years and over,” said Mene Pangalos, executive vice-president, BioPharmaceuticals R&D, in the press release. “We look forward to filing our regulatory submission for Emergency Use Authorization in the US and preparing for the rollout of millions of doses across America.”

Source: AstraZeneca