The CEO of AstraZeneca, the British-Swedish firm co-developing a coronavirus vaccine with Oxford University, has claimed the Covishield vaccine will protect 95 per cent of patients and that it is as effective as the Pfizer and Moderna alternatives.
CEO Pascal Soriot made the claim to the Sunday Times, saying scientists had figured out a “winning formula to get efficacy up there with everybody else”.
As per the interim results pf Phase III trials of the vaccine, Covishield had an average efficacy of 70 per cent on average. The number comes from differing results for two dosing regimes: One where a half dose followed by a full dose showed 90 per cent efficacy, and one where two full doses came up with 62 per cent efficacy.
Since the more effective half-dose regime was given accidentally, a separate branch of the trial is now investigating that more fully. The “potency miscalculation” came after Oxford utilised a new quality test method for vaccine received from Italian supplier IRBM/Advent. The method overestimated the potency of one batch, prompting Oxford to administer it as a half dose and receiving permission from the British drug regulator.
AstraZeneca executive vice president Mene Pangalos called the mistake “serendipity,” telling Reuters that data analysis later indicated the half dose, followed by a full-dose booster shot, was much more effective than two full doses.
Concerns have been raised over the pooled method of calculating the vaccine’s efficacy, as well as over the fact that the low-dose arm of the trial did not include anyone over the age of 55—the most vulnerable group to COVID-19.
However, the researchers say the low-dose vaccine regime remained more effective even in the under-55 group than the regular-dose one.
While the UK government has asked the country’s drug regulator to start the approval process, AstraZeneca has said it would undertake a new global-trial of the lower-dose regime.
While the Oxford vaccine was long considered a front-runner among COVID-19 vaccines, it was the vaccines by Pfizer/BioNTech and Moderna that were approved and deployed first, with Pfizer’s vaccine already in circulation in the US and Europe.
However, the Oxford vaccine requires less refrigeration and is less expensive, making it a target candidate for developing countries, with three billion doses expected to be made ready by next year.
PTI reported of Saturday that the Oxford vaccine may become the first to receive regulatory approval in India, which may come as early as next week. Emergency use authorisation would be given, if approved, to the Serum Institute of India—the world’s largest vaccine maker—who have already manufactured million of doses.