The coronavirus vaccine being developed by scientists at Oxford University may not prevent people from becoming infected with the disease after all, experts have warned.
In the latest animal trials of the vaccine carried out on rhesus macaques, all six of the participating monkeys went on to catch the coronavirus.
Dr William Haseltine, a former Harvard Medical School professor, revealed the monkeys who received the vaccine had the same amount of virus in their noses as the three non-vaccinated monkeys in the trial.
This suggests the treatment, which has already received in the region of £90million in government investment, may not halt the spread of the deadly disease.
The bombshell comes after initial reports last week suggested the vaccine offered ‘some’ immunity against the virus, and stopped it getting deep into the lungs, where it becomes deadly.
The vaccine, known as ChAdOx1 nCov-19, is currently undergoing its first human clinical trial, as nations accelerate their efforts to tackle the deadly virus.
It is the latest setback to hopes of a cure after a professor at Imperial College London, where researchers are also studying a potential vaccine, warned a working vaccine is unlikely to be ready this year.
Experts said people should not have ‘false expectations’ despite ministers revealing they are hoping to have 30 million vaccine doses for the UK by September.
A coronavirus vaccine developed in Britain may not stop those treated being infected. Pictured: A volunteer is injected with the vaccine in Oxford University’s vaccine trial
Discussing the Oxford vaccine, Dr Haseltine wrote on Forbes: ‘All of the vaccinated monkeys treated with the Oxford vaccine became infected when challenged.
‘There was no difference in the amount of viral RNA detected from (nasal secretions) in the vaccinated monkeys as compared to the unvaccinated animals.
‘Which is to say, all vaccinated animals were infected.’
Professor of Molecular Biology at Nottingham University, John Ball, warned: ‘The amount of virus genome detected in the noses of the vaccinated and un-vaccinated monkeys was the same and this is concerning.
‘If this represents infectious virus and a similar thing occurs in humans, then vaccinated people can still be infected and shed large amounts of virus.
‘This could potentially spread to others in the community.’
Professor of Immunology and Infectious Disease at Edinburgh University Eleanor Riley said the number of antibodies produced was ‘insufficient’ to prevent infection and viral shedding.
‘If similar results were obtained in humans, the vaccine would likely provide partial protection against disease in the recipient but would be unlikely to reduce transmission in the wider community,’ she said.
Business Secretary Alok Sharma yesterday announced a deal between Oxford University and AstraZeneca which could see millions of vaccines available in the UK by September
The vaccine’ limitations were revealed when the full trial results were published last week.
They also show three of the six vaccinated monkeys began breathing more rapidly than normal after becoming infected, making them clinically ill.
However, none developed damage to the lungs. This was seen in two of the monkeys that did not get the vaccine.
WHAT IS THE DIFFERENCE BETWEEN VACCINES CREATED BY OXFORD AND IMPERIAL COLLEGE?
The science behind both vaccine attempts hinges on recreating the ‘spike’ proteins that are found all over the outside of the COVID-19 viruses.
Both will attempt to recreate or mimic these spikes inside the body. The difference between the two is how they achieve this effect.
Imperial College London will try to deliver genetic material (RNA) from the coronavirus which programs cells inside the patient’s body to recreate the spike proteins. It will transport the RNA inside liquid droplets injected into the bloodstream.
The team at the University of Oxford, on the other hand, will genetically engineer a virus to look like the coronavirus – to have the same spike proteins on the outside – but be unable to cause any infection inside a person.
This virus, weakened by genetic engineering, is a type of virus called an adenovirus, the same as those which cause common colds, that has been taken from chimpanzees.
If the vaccines can successfully mimic the spikes inside a person’s bloodstream, and stimulate the immune system to create special antibodies to attack it, this could train the body to destroy the real coronavirus if they get infected with it in future.
The same process is thought to happen in people who catch COVID-19 for real, but this is far more dangerous – a vaccine will have the same end-point but without causing illness in the process.
Dr Haseltine added: ‘It is crystal clear that the vaccine did not provide sterilising immunity to the virus challenge, the gold standard for any vaccine.
‘It may provide partial protection.’
The vaccine entered its first human clinical trial last month. As many as 1,110 people across Oxford, Southampton, London and Bristol are taking part. Half are receiving the vaccine while the others are given a control.
The government announced a further £65.5million investment in the Oxford vaccine trials yesterday.
Business Secretary Alok Sharma has praised the vaccine, saying yesterday: ‘The speed with which Oxford University has designed and organised these complex trials is genuinely unprecedented.
‘This new money will help mass produce the Oxford vaccine so that if current trials are successful we have dosages to start vaccinating the UK population straight away.
‘The UK will be the first to get access and we can also ensure that in addition to supporting people here, we are able to make the vaccine available to developing countries at the lowest possible cost.’
Imperial College London is also working on a vaccine to stop coronavirus, which it says aims to trigger a rapid immune response using the ‘spike’ protein on the virus surface.
It has received more than £20 million in funding so far.
However, Robin Shattock, head of mucosal infection and immunity at Imperial, said it is ‘important not to have a false expectation that it is just around the corner’.
Prof Shattock said there are an estimated 100 coronavirus vaccines in development around the world.
But the ‘most optimistic estimation’ would suggest that one proven to be successful will not be ‘readily available for wide scale use into the beginning of next year’.
Imperial’s Professor Robin Shattock today said it ‘may take quite some time’ for researchers to develop a working vaccine
He said it ‘may take quite some time’ for researchers to get all the data they need to prove without doubt that a vaccine actually works.
Asked if the UK is ‘on the brink’ of getting a working vaccine, Prof Shattock told the BBC: ‘I think we need to distinguish two different things. One of the hurdles is making vaccine doses, obviously AstraZeneca can do that and that is a good thing but that is very different to having the data that proves that the vaccine actually works.
US firm Moderna’s experimental vaccine shows potential to block coronavirus in human trials
Moderna’s experimental COVID-19 vaccine produced antibodies that could ‘neutralize’ the new coronavirus in patients in a small early stage clinical trial, the company announced Monday, sending its shares up by more than 20 percent.
The levels of the antibodies – immune cells made in response to a germ, which may provide protection against reinfection – were similar to those in blood samples of people who have recovered from COVID-19, early results from the study conducted by the National Institutes of Health (NIH) showed.
Participants were given three different doses of the vaccine and Moderna said it saw dose-dependent increase in immunogenicity, the ability to provoke an immune response in the body.
Moderna noted that the early trial is intended to determine the safety and side effects of the vaccine and, although the early results are promising, it’s too soon to say whether the shot candidate can actually block the virus.
The company has been in the lead of the US race to make a COVID-19 vaccine, and nearly neck-in-neck with an Oxford University effort to make one in the UK.
‘We need to have those data to show that it is ready and appropriate to roll out. It may take quite some time to get that data, it is a numbers game.
‘And in fact as we are better at reducing the number of infections in the UK it gets much harder to test whether the vaccine works or not.
‘There are no certainties, no guarantees in developing any of these candidates so I think it is important not to have a false expectation that it is just around the corner.
‘It may be longer than any of us would want to think.’
Some health experts have suggested a vaccine could take as long as 18 months to develop while others have cautioned one may never be found.
Prof Shattock said: ‘I think we need to keep context here. Obviously there could be some success, we could see things working earlier if we get the numbers and the kind of AstraZeneca approach is preparing for that success.
‘But it is probably very likely that we won’t really get the evidence until into early next year and then there is a difference between a solution in the UK which could be rolled out and a global solution.
‘A global solution is likely to take much longer just because of the sheer operational effort to make billions of doses and make them available worldwide.’
Prof Shattock said he believed there is a ‘very high chance of seeing a number of vaccines that work’ as he said the evidence suggested coronavirus is ‘not such a hard target as others’.
He added: ‘My gut feeling is that we will start to see a number of candidates coming through with good evidence early towards next year – possibly something this year.
‘But they won’t be readily available for wide scale use into the beginning of next year as the kind of most optimistic estimation.’
Six drugs for treating coronavirus are currently in clinical trials worldwide.
China has four potential vaccines in clinical trials at present, three of which have entered stage two.
Trials of one vaccine developed by Beijing-based company Sinovac Biotech in April appeared to arrest the development of Covid-19 in monkeys.
However, it used a Sars-Cov-2 virus, whereas the Oxford vaccine uses a weakened version of adenovirus (common cold) that causes infections in chimpanzees, with the coronavirus spike protein added to it.
Sinovac Biotech has secured land and loans for it to develop a facility to mass produce any effective vaccine.
The company has previously been involved in developing vaccines for hepatitis A, hepatitis B and H1N1 influenza.