Oxford Covid vaccine trial confirms encouraging results for the elderly
The coronavirus vaccine under development by Oxford university and AstraZeneca has elicited a strong immune response and been shown to be safe in older adults, a group at disproportionate risk of developing severe Covid-19.
In phase 2 trial results published in The Lancet, researchers said the vaccine had fewer adverse effects in older people than in younger adults, and that it produced a similar immune response in both groups.
The Financial Times first reported on the promising data last month.
Testing of the Oxford-AstraZeneca vaccine is at an earlier stage than work on vaccines from Moderna and Pfizer-BioNTech, which have both been shown to protect around 95 per cent of people from infection.
No data have been published on whether the Oxford-AstraZeneca vaccine prevents people from developing Covid-19. But phase 3 trials measuring its so-called efficacy are under way with results expected before the end of the year.
Phase 2 trials are not definitive and do not measure efficacy, the metric regulators seek to warrant approval.
Oxford’s Andrew Pollard, the study lead, noted that immune responses are usually weaker in older adults because the immune system deteriorates with age. “As a result, it is crucial that Covid-19 vaccines are tested in this group who are also a priority group for immunisation,” he said.
The Oxford-AstraZeneca vaccine, the most promising jab being worked on in the UK, is known as ChAdOx1 nCoV-19.
Pfizer-BioNTech and Moderna spurred widespread optimism and market rallies after announcing better than expected phase 3 efficacy figures for their jabs, raising the prospect of at least two vaccines being approved on an emergency basis before the end of the year.