Earlier this week, AstraZeneca released more data to support its vaccine efficacy. The interim results from the phase 3 clinical trial of more than 32,000 people found the vaccine was 79% effective against symptomatic disease, and 100% effective against severe disease and death.
But soon after the results were published, questions were raised in the US by the independent Data and Safety Monitoring Board, which said AstraZeneca may have provided “outdated information” from the trial, which gave “an incomplete view” of the results.
In response, AstraZeneca has just released the additional data which confirm the efficacy results reported earlier this week. This has now been presented to the independent Data Safety Monitoring Board. An additional 49 cases have now been added to the previously announced interim analysis.
The primary endpoint, vaccine efficacy at preventing symptomatic Covid-19, was 76%, occurring 15 days or more after receiving two doses given four weeks apart. In addition, results were comparable across age groups, with vaccine efficacy of 85% in adults 65 years and older. A key secondary endpoint, preventing severe or critical disease and hospitalisation, demonstrated 100% efficacy.
The vaccine was well tolerated, and no safety concerns related to the vaccine were identified.
Mene Pangalos, the executive vice-president of AstraZeneca’s bio pharmaceuticals research and development, said: “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.”
AstraZeneca will also submit the primary analysis for peer-reviewed publication in the coming weeks.
Associate professor Paul Griffin, who is the director of infectious diseases at Mater Health Services in Queensland, said people should believe in the vaccine and that it is safe and effective.
It is such a shame that a vaccine with so much evidence supporting its safety as well as efficacy continues to be shrouded in controversy.
We heard very positive news almost a week ago that the European Medical Authority’s safety committee concluded that the vaccine was not associated with an increase in the overall risk of blood clots and therefore the benefits of receiving the vaccine continue to outweigh the risk of side effects.
The request for more vaccine data was standard practice in drugs approval processes but had played out very publicly due to the intense focus on Covid and need for transparency, Griffin said, but he said it was important not to overreact when questions are raised.
“As the only Covid-19 vaccine currently able to be manufactured in Australia, and [with] the exciting news that the first four batches have been approved for release, we need to continue to support its use in an evidence-based manner with faith in our regulator the TGA, and not falsely sound the alarm over coincident events with no established link or based on perceived issues with how results are communicated in the press,” he said.