Scientists hunting vaccine start recruiting over-55s for trials

Bill Gardner

OXFORD University scientists leading the global search for a coronavirus vaccine are to recruit “very healthy” over55s to help with clinical trials.

The next phase of testing will focus on how older adults’ immune systems respond, the Oxford Vaccine Group said yesterday.

Scientists are looking for 10,260 people from across the UK to take the jab, considered a front runner in the world’s race for a Covid-19 vaccine.

The Government has said that if the treatment proves successful in human trials, then up to 30million doses could be available for the UK by September.

But Prof Andrew Pollard, head of the Oxford Vaccine Group, said it was “very difficult” to know when scientists will have proof that it is effective.

Work began in January on the vaccine, which uses a virus taken from chimpanzees and has been developed by the University of Oxford’s Jenner Institute and the Oxford Vaccine Group.

The first phase of trials involved 160 healthy volunteers aged between 18 and 55.

Now scientists want to recruit up to 10,260 people for phases II and III, which involve vastly increasing the number of volunteers and expanding the age range to include older adults and children.

Adult participants will be selected at random to receive one or two doses of either a vaccine known as Chadox1 ncov-19, or a licensed vaccine (MENACWY), which will be used as a “control” for comparison.

Chadox1 ncov-19 is made from a weakened version of a common cold virus from chimpanzees that has been genetically changed to make it impossible for it to grow in humans.

This has been combined with genes that make proteins from the Covid-19 virus (SARS-COV-2) that play a key role in the infection pathway of the SARSCOV-2 virus.

The next phase of vaccine testing will focus on the immune response in older adults, Prof Pollard said.

“There are two groups, the first are those over the age of 55, and they are divided into those being 55 to 70, and those who are over 70,” he said. “And in that group we are looking very closely at immune responses, particularly in the oldest adults where often immune responses are a bit weaker.”

He said a second group of 10,000 front-line workers will also participate in the study. Asked who should come forward to take part, Prof Pollard said “very healthy individuals” will be initially selected.

Production of the vaccine has already been scaled up ahead of the trial to prepare for potential deployment.

Astrazeneca said this week that it had the capacity to manufacture one billion doses of the vaccine, and could begin supply in September.