Hopes build over UK Covid vaccine as Oxford drug trials show test subjects are developing key antibodies and T-cells for fighting off killer disease
- UK scientists are ‘80 per cent’ confident that a jab could be ready by September
- Trials finding that participants develop antibodies and killer T-cells to fight it
- Oxford study with AstraZeneca is in global race to produce the best vaccine
A vaccine against coronavirus being developed in Britain is showing positive signs it could work after trials revealed that participants are developing cells that can kill off the disease, it was revealed today.
The team of scientists in Oxford have already said they are ‘80 per cent’ confident they can have a jab available by September with more good news now expected this week.
Today it has emerged that trials have revealed that the vaccine is kickstarting an antibody reaction in the body and the crucial T-cells that will kill off the virus in the body.
Some 8,000 Britons are taking part in a major trial of the Oxford vaccine, which is being manufactured by pharmaceutical firm AstraZeneca. But, as rates of coronavirus have fallen in this country, researchers are also aiming to vaccinate 4,000 individuals in Brazil and 2,000 in South Africa.
A source told ITV News’ political editor Robert Peston: ‘An important point to keep in mind is that there are two dimensions to the immune response: antibodies and T-cells. Everybody is focussed on antibodies but there is a growing body of evidence suggesting that the T-cells response is important in the defence against coronavirus’.
A vaccine against coronavirus being developed in Britain is showing positive signs it could work after trials revealed that participants are developing cells that can kill off the disease
University of Oxford
Clinical teams at the Oxford University’s Jenner Institute and Oxford Vaccine Group began developing the ChAdOx1 nCoV-19 vaccine in January, now named AZD1222 since a manufacturing partnership with pharmaceutical giant AstraZeneca was secured.
Human trials started on April 23 and they are now in the final phase.
Lead of the project Professor Sarah Gilbert told The Times she is ’80 per cent’ confident of its success.
Imperial College London
Professor Robin Shattock is leading a team working to produce a vaccine at Imperial College.
Fifteen volunteers have already been given the trial vaccines and testing is expected to ramp up to include as many as 200-300 new participants in the coming weeks.
A second trial, involving 6,000 people, will come later.
But Professor Shattock said the vaccine won’t be available until at least 2021 even if everything goes according to plan.
If the jab works, the team want to make it as cheap as possible so the entire British population could be vaccinated for the ‘really good value’ of just under £200million.
Massachusetts-based Moderna was the first US company to start human trials of its potential Covid-19 vaccine, known as mRNA-1273, on March 16.
The jab has proven to trigger an immune response in all 45 injected volunteers, according to a study published in the prestigious New England Journal of Medicine on July 14.
Moderna’s shot showed early promise in its phase 2 human tests last month. The company reported that it triggered antibody production on par with that seen in recovered coronavirus patients.
Chinese vaccine Ad5-nCoV, made by CanSino, was the very first shot to enter clinical trials earlier this year and is a leading candidate.
A trial of 108 healthy volunteers in China showed it safely triggered an immune response in participants.
Results published May 22 in The Lancet showed most of the people dosed with the vaccine had immune responses, although their levels of antibodies thought to neutralize the virus were relatively low. Researchers saw a stronger ramp-up of other immune compounds, called T-cells, that might also help fight the infection off.
Pfizer and BioNTech have been working on a number of potential Covid-19 vaccines under the ‘BNT162 program’.
It reported positive preliminary results from the ongoing Phase I/II clinical trial of one called BNT162b1 on July 1.
Data is available for the trial of BNT162b1 on 24 volunteers. The results showed that it was well tolerated and produced dose dependent immunity.
Dr Kathrin Jansen, Pfizer’s head of vaccine research and development, said the vaccine ‘is able to produce neutralizing antibody responses in humans at or above the levels observed’ in Covid-19 survivors.
Pfizer received fast track designation from the US Food and Drug Administration (FDA) for two of their four potential Covid-19 vaccines this month.
Johnson & Johnson
The drug giant started work on the vaccine in January, two months before Covid-19 was labelled a global pandemic.
A vaccine trial spearheaded by Johnson and Johnson will start recruiting people in September, with clinical data available by the end of the year.
An ’emergency use’ batch of the vaccine is anticipated to be authorised as early as 2021, which would likely be prioritised for vulnerable people.
A jab against coronavirus should last for several years at least, the British scientist whose own vaccine project is the global front-runner revealed earlier this month.
Professor Sarah Gilbert told MPs she was optimistic that a vaccine would provide ‘a good duration of immunity’.
She is the world-renowned expert leading an Oxford University team devising a vaccine, so her claim could help to dispel the fears over how long protection against Covid-19 might last.
Concerns had been raised after those with other types of coronavirus – which are less dangerous and cause the common cold – were able, in tests, to be reinfected within a year.
But Professor Gilbert told the Commons science and technology committee there may be a better result from a vaccine than the natural immunity acquired when individuals simply recover from a virus. She said: ‘Vaccines have a different way of engaging with the immune system, and we follow people in our studies using the same type of technology to make the vaccines for several years, and we still see strong immune responses.
‘It’s something we have to test and follow over time – we can’t know until we actually have the data – but we’re optimistic based on earlier studies that we will see a good duration of immunity, for several years at least, and probably better than naturally-acquired immunity.’
The key question is whether the vaccine will protect them from becoming infected, or simply make them less ill. It may also work less well in older people because their immune systems are weaker.
Sir John Bell, regius professor of medicine at Oxford University, also gave evidence to the committee, warning that the UK must ‘prepare for the worst’ this winter, rather than rely on the development of a vaccine.
But he said he has now seen tests for coronavirus of a good standard which can produce a result in a ‘few minutes’.
Sir John said: ‘That would be transformative because we could all test ourselves regularly and test our kids after they’ve been off to a rave and all that stuff.’
He also urged Britons to have the flu jab to ‘avoid pandemonium in A&E departments’.
Trials of a potential antibody treatment that could protect older people from coronavirus have also started.
Instead of a traditional vaccine the proposed treatment would see patients given a three-minute infusion of antibodies to the virus that could provide protection for up to six months.
For people whose immune systems do not respond to a vaccine, including those taking immunosuppressant drugs or undergoing chemotherapy, it could provide alternative way of developing resistance to the virus.
Older people also have less of a response to vaccines so the antibody infusion could help give extra protection for older people who are more at risk from coronavirus, reported The Times.
Pharmaceutical firm AstraZeneca are trialling the treatment and the drug maker is also working with Oxford University on a potential vaccine.
As well as preventing people catching the disease antibody therapy can help people who have caught it recover more quickly.
Sir Mene Pangalos, who heads the company’s research into treating respiratory diseases told The Times: ‘There’s a population who are elderly that [may not] get a particularly good immune response to the vaccine,
‘In those instances you might want to prophylactically treat those patients with an antibody to give them additional protection.’
It is not yet clear if the treatment will work and the first human trial will only have around 30 participants.
If no safety issues arise larger scale testing could begin in the autumn.
Sir Mene added: ‘We’re going to do this as fast as we can
‘Obviously we’ve got to show that you’re safe but antibodies are well known entities – it should be safe.
The trial comes following initial research at Vanderbilt University in the United States which looked into monoclonal antibodies, which can imitate the antibodies created by the body after being infected by coronavirus.
However the antibody therapy is not expected to be an alternative to a vaccine as it will cost a much while not providing protection for as long a period of time.
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