New partial results from a coronavirus vaccine trial have been welcomed by the head of the Oxford Vaccine Group, who claimed they show it is safe and around 70% effective.
Developed by AstraZeneca and Oxford University, the vaccine is not-for-profit, and is intended to be distributed to low and middle-income countries.
Andrew Pollard, the head of the Oxford Vaccine Group, said “we have no safety concerns about the vaccine,” with no hospitalisations or severe disease among those who received it, and results from all study locations consistently showing benefit.
However, according to results published in the medical journal the Lancet on Tuesday, there was an error over the dosages given to one of the groups, making the results slightly more confusing.
The results show those who were given two standard doses achieved 62% protection, while those mistakenly given a lower first dosage achieved 90%.
That second group with the higher efficacy only consisted of 2,741 people, leading some independent experts to say the number is too small to judge the value of using a lower initial dosage.
The half-dose group also didn’t include anyone over 55, and among others in the study, only about 20% were in that age group.
"Vaccine efficacy for the prespecified primary analysis (combining dose groups) against the primary endpoint of COVID-19 occurring more than 14 days after the second dose was 70·4%," declared the study in the Lancet.
"No serious adverse events or deaths that were treatment associated occurred in ChAdOx1 nCoV-19 recipients," it added.
It listed the strengths of the study as the "large sample size, randomisation to vaccine groups, inclusion of diverse sites targeting different races and ethnicities, standardisation of key elements between the trials, balance of participant characteristics between the vaccine groups, inclusion of all participants in the safety assessment, and having similar results in Brazil as in the UK for the SD/SD (standard dose) group, which lends credibility to the results."
It is yet to be determined how effectively the vaccine, developed by Oxford University and AstraZeneca, might help protect those over 55, which remains a key concern.
It’s unclear if the results will be enough to lead regulators in the United Kingdom and elsewhere to approve its use right away.
"Our data are all published, we're very confident in the results," Pollard said. "We'll have that stamp of approval, I hope, before too long."
On Tuesday, the UK became the first Western country to start a mass vaccination program after British regulators authorized the use of a COVID-19 shot developed by US drugmaker Pfizer and Germany’s BioNTech.
US and European Union regulators may approve the vaccine in the coming days or weeks, fueling a global immunisation effort.