Oxford coronavirus vaccine ‘has only been tested on 500 over-70s’

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Oxford coronavirus vaccine ‘has only been tested on 500 over-70s’ amid fresh concerns over its effectiveness

  • High hopes for Oxford University’s ‘ChAdOx’ jab but only 1,000 or so of the 10,000 people recruited to UK arm of Oxford’s trial are aged 70 or over
  • Half of them have been given the vaccine and half have had a placebo
  • Last night, former immunisation ‘tsar’ Professor David Salisbury said relatively small numbers might not be enough to generate meaningful result

By Stephen Adams for The Mail on Sunday

Published: | Updated:

Britain’s front-running Covid vaccine has only been tested on about 500 elderly people in this country, raising questions about how effective it might be for a vital section of the population.

There are high hopes for Oxford University’s ‘ChAdOx’ jab but only 1,000 or so of the 10,000 people recruited to the UK arm of Oxford’s trial are aged 70 or over. Half of them have been given the vaccine and half have had a placebo.

Last night, former immunisation ‘tsar’ Professor David Salisbury said the relatively small numbers might not be enough to generate a meaningful result.

‘Clearly, if you’ve just got 500 vaccinated and you’ve given 500 the placebo and you are looking to see a significant difference in protection between the two… you may not get much out, in terms of data,’ he said.

There are high hopes for Oxford University’s ‘ChAdOx’ jab but only 1,000 or so of the 10,000 people recruited to the UK arm of Oxford’s trial are aged 70 or over. Half of them have been given the vaccine and half have had a placebo. (File image)

However, he added that early results appeared to show that older people given Covid vaccines developed good immune responses, so he was hopeful they would work well in the elderly.

The issue is critical because the virus is much more deadly in older people. 

An 80-year-old is about 1,000 times more likely to die of the virus than a 20-year-old, while five out of every six Covid-related deaths have been in the over-70s.

Earlier this month, Kate Bingham, head of the UK’s Vaccine Taskforce, gave a clear signal that Covid vaccination is to be aimed at older people, even though vaccines are often less effective in that group as their immune systems tend to respond less strongly.

Oxford has launched parallel trials in Brazil (above), South Africa and the US ¿ but only the American 'arm' is enrolling over-65s. AstraZeneca, which is handling the US trial enquiries, refused to say how many over-65s have been recruited there so far

Oxford has launched parallel trials in Brazil (above), South Africa and the US – but only the American ‘arm’ is enrolling over-65s. AstraZeneca, which is handling the US trial enquiries, refused to say how many over-65s have been recruited there so far

For example, the flu vaccine given in 2016-17 was completely ineffective in the over-65s, according to data from Public Health England. It did, however, work well in younger people.

As Oxford’s Covid vaccine works in a different way, there is no specific reason to believe it will be a dud in the elderly but all the leading jab contenders are acutely aware of the issue.

Oxford has launched parallel trials in Brazil, South Africa and the US – but only the American ‘arm’ is enrolling over-65s. AstraZeneca, which is handling the US trial enquiries, refused to say how many over-65s have been recruited there so far.