A coronavirus vaccine may be more effective as a nasal spray or inhaler, researchers behind Britain’s most promising Covid-19 jabs claimed today.
Oxford University and Imperial College London scientists believe getting the vaccine directly into the lungs may be the best way to protect people against the respiratory infection.
Both universities are currently testing their Covid-19 jabs — administered by injection into the muscle — on thousands of humans in clinical trials, in the global race to find a way to end the pandemic.
The Oxford vaccine, leading the global race for a Covid cure, is currently being trialled on more than 10,000 people in Britain, Brazil and South Africa after moving in phase III trials.
Meanwhile the first healthy volunteer today received a ‘small dose’ of Imperial College London’s vaccine and has reported no sign effects.
Their vaccine candidates work by training the body to identify the coronavirus so it can rapidly fight off the illness before it has chance to cause an infection. Neither have been proven to work in humans yet.
But the lead scientists behind the jabs are already planning to launch a second wave of studies looking into so-called mucosal immunisation.
Mucous membranes are protective layers of tissue that line the surfaces of internal organs, including the lungs and respiratory tract. They also coat entry points such as the nose and mouth, catching pathogens that try to get into the body.
They form a powerful, sticky mesh that traps viruses which are trying to invade. By administering a vaccine at the entry points, it trains the mucosa to be able to identify Covid-19 and block it from getting through.
This kind of vaccine can be given through a nasal spray, as is done for influenza in children, or inhaled.
A coronavirus vaccine may be more effective if it is taken via a nasal spray (which is already being used in flu immunisation) the researchers behind Britain’s Covid-19 jab frontrunners said today
How the injectable vaccines from Imperial College London and Oxford University would work
Professor Robin Shattock, an immunologist at Imperial, told the House of Commons Science and Technology Committee today: ‘At the moment most of the vaccines are being delivered by conventional intramuscular injection.
‘The reason is that’s the easiest and fastest to get off the starting blocks and into studies. But a number of us interested in looking at mucosal immunisation, as well.
‘And certainly Professor Gilbert (from Oxford) and myself are already in discussion as to how me might be able to move that as a second wave of clinical study.’
Sarah Gilbert, professor of vaccinology at Oxford University, added: ‘With oral or nasal you would have much stronger mucosal response.
‘That’s probably really important in the protection against respiratory pathogens. It’s also very difficult to study and we’re not yet very good at measuring it.
‘But, as Professor Shattock said, we’re very interested in looking at delivery to the respiratory tract, either intranasal delivery [via a nasal spray] or aerosol delivery [using an inhaler].
Professor Robin Shattock, an immunologist at Imperial, told the House of Commons Science and Technology Committee today he was ‘very interested’ in exploring mucosal vaccinations
Sarah Gilbert, professor of vaccinology at Oxford University, said administering vaccine directly into the respiratory tract could better protect the lungs against infection
What is the difference between the vaccines being developed by Oxford University 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.
‘This takes the vaccine itself right down into the lungs where it can access the same tissue that would be reached by the virus infection.’
Conventional vaccines do not work as consistently or effectively in older people, who are most at risk of falling seriously ill with Covid-19.
This is because their immune systems become blunted with age and struggle to mount a powerful response to infection.
The scientists believe the mucosal vaccinations may be a more effective way of protecting elderly people because it directly strengthens the lungs, which are targeted by Covid-19.
But Professor Gilbert added: ‘We have to proceed with caution because the technology is very new and we need to make sure it’s safe.
‘There has been some small studies of vaccines delivered by aerosol and of course we have the intranasal delivery of the flu vaccine used in children.
‘But delivering a vaccine through the nose is actually getting very close to the brain so we need to make sure that’s gonna be safe.
‘Putting it down into the lungs, you’re exposing a very large surface area to the new entity [Covid-19].
‘[We want to] understand how the different types of antibodies in the respiratory tract could be generated by vaccination – and it may mean you could have a more effective vaccine by delivering to the respiratory tract or indeed orally.’
Scientists around the world are racing to find a vaccine, which is considered to be the only way to safely stop the pandemic and end draconian lockdowns designed to contain the virus.
Oxford and Imperial’s injectable vaccines are two of the frontrunners to cure the disease, but the researchers behind them admit they won’t be perfect.
The competing universities said today they could end up being used together to provide lasting immunity.
Oxford University’s vaccine was first out of the blocks and is already being tested on at least 10,000 people in the UK and Brazil, while Imperial College’s jab only started human trials last week.
But Professor Shattock said that although the two vaccines were being seen as rivals, ultimately they could well be used together because the way they work differs.
Oxford University’s jab was known as ChAdOx1 nCoV but has now been called AZD1222 since a partnership was pharmaceutical giant AstraZeneca was secured
FIRST VOLUNTEER INJECTED IN IMPERIAL COLLEGE LONDON’S COVID-19 VACCINE TRIALS
The first healthy volunteer has received a ‘small dose’ of a potential Covid-19 vaccine developed by researchers from Imperial College London.
The participant, who has asked to remain anonymous, is reported to be in good health with no safety concerns after being injected on June 19.
A second booster dose will follow within four weeks. Imperial now joins Oxford University in the UK’s race to find an effective vaccine to stop the pandemic.
Professor Robin Shattock, from the department of infectious disease at Imperial, who is leading the research, said his team’s work is ‘an important step’ for their vaccine candidate. He added: ‘We now eagerly await rapid recruitment to the trial so that we can assess both the safety of the vaccine and its ability to produce neutralising antibodies which would indicate an effective response against Covid-19.
‘I look forward to our progress in the coming months.’
Fifteen healthy volunteers are expected to receive their first dose in the coming days as part of the initial phase of the trial.
To assess safety as well as to find the optimal dosage, the researchers are starting with a low dose and gradually increasing it to higher doses for subsequent volunteers.
Around 300 healthy participants are expected take part in this trial. Imperial’s RNA vaccine uses synthetic strands of genetic code based on the genetic material of Sars-CoV-2, the coronavirus responsible for the pandemic.
It works by delivering genetic instructions to muscle cells to make the ‘spike’ protein on the surface of Sars-CoV-2.
The presence of this protein provokes an immune response, offering protection against Covid-19.
If the vaccine is safe and shows promising immune response, a further trial involving 6,000 people is expected to go ahead in October.
While the Oxford vaccine was ahead in the race to protect against Covid-19, he said it could be limited by an inability to be used on the same person time and time again.
However, Professor Shattock believed it would be possible to use the Imperial jab to bolster an individual’s immunity ‘multiple times’.
Scientists around the world increasingly think booster jabs will be needed to maintain protection against the virus that causes Covid-19, as initial immunity provided by a vaccine may well fade over time.
Last Tuesday Pascal Soriot – chief executive of pharmaceutical giant AstraZeneca, which has partnered with Oxford to produce a billion doses of the jab – fuelled those fears when he said he was confident the jab would provide immunity for ‘about a year’.
Natural immunity to other coronaviruses, which cause common colds, is thought to last from several months to a couple of years.
The potential flaw with the Oxford vaccine is that it uses a harmless virus as a microscopic Trojan horse to smuggle in tiny fragments of Covid-19 coronavirus RNA – the bug’s genetic blueprint.
The recipient’s immune system learns to identify this RNA as foreign, and so creates antibodies to protect against it.
But experts fear that if a person is subjected to multiple doses of this jab, their body might ‘mistakenly’ develop an immune response to the Trojan horse virus itself – called an adenovirus – thus rendering it useless.
As the Imperial vaccine does not use a virus as the means of smuggling in RNA, it should avoid this problem, said Prof Shattock.
Professor Shattock said the Oxford vaccine was ‘very good to be able to give an initial immune response, but it has its limitations in that the ability to reboost immunity may be less good than other approaches’.
By contrast, he said: ‘The approach that we are developing allows you to re-boost multiple times.’
He continued: ‘We are often pitted against each other, or seen to be in a race against each other, but actually we are collaborating very closely together, exchanging material, and the two approaches may well be able to be used together, in a ‘prime, boost’ approach.’
UK Health Secretary Matt Hancock last week announced frontline NHS and social care workers, over-50s and Britons with heart or kidney disease would be the first in line to get a Covid-19 vaccine.
Britain’s top vaccine scientists say Covid-19 has lots of ‘tricks’ to deceive the immune system
The coronavirus has lots of ‘immunological tricks up its sleeve’ that make it hyper-infectious, according to one of Britain’s top vaccine scientists.
Peter Openshaw, professor of experimental medicine at Imperial College London, said the virus is ‘surprisingly’ good at ducking the human immune system — despite only jumping from animals six months ago.
He said normally it takes years of co-existing with humans for any virus to evolve these traits.
Professor Openshaw told the House of Lords Science and Technology Committee today: ‘In terms of durability, viruses often have a way of modulating the host’s immune response.
‘It’s the way they’ve evolved to tune down the immune response that’s generated by the virus. That would usually be particularly strong in virus that’s had long time to co-evolve with human host.
‘What surprises us about this novel virus that’s only recently jumped from bats to humans, is already seems to have a lot of immunological tricks up its sleeve and is able to interfere with the immune response and in a way disseminate in a way that you wouldn’t really expect a virus that has only just moved into the human population.
‘We wonder why that is. We wouldn’t have thought that a virus could behave in such a complex way when its only just been introduced into a new species.’
He added: ‘So maybe there are tricks it has learned while evolving in another species that have cross over effect.’
Professor Openshaw shot down theories that the virus had already infected humans before.
He also ruled out the possibility that had been manufactured or interefered with in a laboratory in China, as has been heavily insinuated by US President Donald Trump.
Professor Openshaw told the committee that he thought it was ‘just chance’ that the virus has learnt to trick the immune system.