AstraZeneca Covid-19 vaccine proves effective

AstraZeneca Covid-19 vaccine proves effective

Drugmaker AstraZeneca announced on Monday that its experimental coronavirus vaccine has shown an average efficacy of 70% in its large scale trials - the latest of several vaccine trials worldwide to post their results this month.

An interim analysis of clinical trials of AZD122 in the United Kingdom and Brazil showed the vaccine had an average efficacy of 70% with protection occurring 14 days or more after two doses.

AstraZeneca chief executive Pascal Soriot said his firm's vaccine would still be highly effective and would have an "immediate impact".

"The results from this trial of the Oxford/AZ vaccine are highly encouraging, demonstrating significant efficacy".

Trials of the Oxford / AstraZeneca found there were no hospitalisations or severe cases of the virus reported in participants who received the vaccine.

The dosing regimen, of giving 25 billion viral particles in the first dose and then 50 billion viral particles, showed an efficacy rate that was significantly higher than the 62% efficacy rate that was achieved when both doses had 50 billion viral particles.

British Prime minister Boris Johnson said it was "incredibly exciting news the Oxford vaccine has proved so effective in trials".

However, the safety of these vaccines and the conditions of their administration aren't yet clear.

The AstraZeneca vaccine uses a modified version of a chimpanzee common cold virus to deliver instructions to cells to fight the target virus, which is different than the new technology known as messenger RNA deployed by Pfizer/BioNTech and Moderna.

Sarah Gilbert, professor of vaccinology at the University of Oxford, said the announcement took everyone a step close to a time when vaccines can be used to bring an "end to the devastation" caused by Covid-19.

The data showing a range of efficacy between 60% and 90% comes after United States rivals published interim data in recent weeks showing efficacy of more than 90%.

AstraZeneca is the third major drug company to report late-stage results for its potential COVID-19 vaccine as public health officials around the world anxiously wait for vaccines that will end the pandemic that has killed nearly 1.4 million people.

The UK researchers say the timing of results for their study will depend on global recruitment to the trial and the incidence of Covid-19.

Dr Michael Head, senior research fellow in global health at the University of Southampton, said: "It's not yet fully clear why a half dose and then a full dose was potentially more protective, but if the final results continue to show this pattern of around 90% effectiveness, this would allow greater vaccine supply not just in the United Kingdom but also globally".

According to preliminary results, the vaccine appeared to be safe and well tolerated at all tested doses.

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