The Bristol volunteers now being recruited to the UK’s main coronavirus vaccine trial will not receive any payment.
Around 1,000 people in the city are expected to be jabbed for Oxford University’s trial, making Bristol the biggest recruiting centre.
The first stage of the study saw 130 Bristol participants recruited in April. They were offered £235 each as “compensation for time, travel and contribution”.
But the larger-scale second phase, which started last month, will not include any reimbursement for Bristol volunteers.
Phase two is set to bring the total number of Bristol participants to around 1,000 – with about 120 of those still to be recruited.
Some volunteers involved in phase two will be paid £390 each – but none of those are being recruited in Bristol.
Only those in ‘Group Five’ will receive £390 during phase two, as compensation for a more intensive schedule. This group is being exclusively drawn from the Oxford pool.
When phase two was announced, it was not made clear there would be zero Bristol volunteers in Group Five.
Professor Adam Finn, leading the Bristol operation, said: “If there was any misinformation, it is simply because this is a complicated project.
“Phase one had a bit more time and trouble involved. There was probably a bit more risk involved than in phase two, because no one had tried out the vaccine before.
(Image: COVID 19 Oxford Vaccine Trial)
“In phase two, Group Five is a more intensively studied group, with lots of visits involved, and they are doing that only in Oxford.”
Bristol participants in phase two will have six to eight blood tests, while those in Group Five will have nine to 11 blood tests.
Prof Finn, a paediatrics expert at the University of Bristol, said phase one of the study involved checking “very carefully for signs of side-effects” to make sure the vaccine is safe.
He said: “What we know is there were no serious safety concerns. Now we’re in the second phase, we’re seeing if it protects against the infection.”
The city’s operation is based at Bristol Children’s Vaccine Centre, with work also being carried out at Southmead Hospital and the Bristol Royal Infirmary.
Prof Finn told Bristol Live earlier this month: “We will all be delighted if [the vaccine] comes through, but we won’t be surprised if doesn’t.
“The worst-case scenario is we never get a vaccine. That is a conceivable outcome.
“Most of us think it is pretty unlikely, but it is a possibility. For example, there is no vaccine against HIV.”
Even in the best-case scenario, with the Oxford vaccine proving effective, it is likely to be winter before doses become widely available.
Prof Finn said: “We would need tens of hundreds of millions of doses for a global pandemic.
“Preparations are already being made, but it would still take until the end of the year.”
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Asked the likelihood of the vaccine working, he replied: “We would all be surprised and disappointed if there was no antibody response, but that doesn’t actually prove it will prevent the disease.
“The influenza vaccines we give every year vary between zero and about 60 per cent effective. Some don’t work at all.
“Over 70 per cent effective would be a great vaccine, but the final proof only really comes when we see the infection is prevented by the vaccine.”
The trial is also recruiting volunteers in Glasgow, Sheffield, South Wales, Nottinghamshire, Hull, Merseyside and other areas.