Oxford scientists are ‘getting close’ to determining whether their Covid-19 vaccine candidate stops coronavirus infection and will ‘definitely’ report before Christmas, the group’s lead researcher has said.
The comments, made to the BBC’s Today programme, come as phase 2 safety trial findings published yesterday in the Lancet showed that the vaccine produced side effects, but that these were less frequent in older than younger adults.
Side effects reported included injection-site pain, feeling feverish, muscle ache and headache, but were ‘less common’ in adults aged 56 and older.
The side effects were more common among participants given the Covid vaccine than the control (MenAWCY) vaccine. Trial participants were not told which vaccine they were given although staff administering the injections were.
The trial has also indicated promising immune responses in older adults, the paper suggested, although further assessment – which will happen via the ongoing larger phase 3 trial – is necessary.
The paper said: ‘ChAdOx1 nCoV-19 appears to be better tolerated in older adults than in younger adults and has similar immunogenicity across all age groups after a boost dose. Further assessment of the efficacy of this vaccine is warranted in all age groups and individuals with comorbidities.’
This comes as promising first human trial results from the Oxford study, published in July, had showed the vaccine provoked a T-cell response within 14 days of vaccination and an antibody response within 28 days.
Professor Andrew Pollard, professor of paediatric infection and immunity at the University of Oxford, told the BBC’s Today programme that scientists were ‘not there yet’ with regards to proving whether the vaccine stops people developing Covid-19.
But he added that final results from the trials are imminent. ‘It’s definitely going to be before Christmas, based on the progress,’ he told the BBC.
He added that he was ‘absolutely delighted’ with interim trial findings that the vaccine triggers a strong immune response ‘even in those over 70 years of age’.
The Oxford/AstraZeneca Covid-19 vaccine has been touted as one of two which may be rolled out as part of a UK vaccination campaign as early as next month.
The UK has ordered more of the vaccine than any other candidate, at 100 million doses.
Earlier this month, the chair of the UK Vaccine Taskforce revealed that these were already being manufactured, with four million doses due to be available ‘by the end of the year’.
The Oxford team started work on developing a vaccine in January this year, entering a global licensing deal with Astra Zeneca and backed by a UK Government investment worth £65.5m.
The UK Government has also pre-ordered 40 million doses of the Pfizer vaccine, which reported 95% efficacy in final phase 3 trial findings yesterday, including 94% efficacy in the most vulnerable over-65s age group.
The Government also secured a deal to purchase five million doses of the Moderna vaccine on Monday of this week, after the US biotech company reported 95% efficacy in phase 3 trial findings.
Although further behind in development, the Oxford vaccine is expected to present fewer logistical challenges than the Pfizer vaccine, which has to be stored at -70C.
Unlike Pfizer and Moderna’s vaccines, which use novel RNA technology, the Oxford candidate is a DNA vaccine – a technology which was pioneered in the 1990s.
GPs in England have been asked to get ready to deliver a Covid vaccination campaign by 1 December via an enhanced service, in anticipation of vaccine trial results and regulatory licencing.
In Scotland, health boards will take the lead on Covid vaccinations, while in Wales health boards and trusts will be involved. Meanwhile, Northern Irish GPs expect a similar programme to that in England, although discussions remain ongoing.