At last there is some hope on the horizon with the Oxford vaccine candidiate yielding early promise and another new inhaled nebuliser treatment based on interferon beta called SNG001. This is just one of 160 or so vaccines that are being developed around the world. I had earlier this year written on the most viable vaccine candidates. The Oxford vaccine is called ChAdOx1 nCoV-19 and the results have just been published in the medical journal the Lancet (July 20th).
The Oxford vaccine is a modified chimpanzee (hence the ‘Ch’) derived adenovirus (hence the ‘Ad’) called ChAdOx1. Adenoviruses cause the common cold. Reassuringly the UK government has secured access to 100 million doses, in addition to 90 million doses of other vaccine candidates. There is also positive news of a new nebuliser or inhaled treatment based on interferon beta (also in early stages of development) from a UK-based company called Synairgen. This is equally encouraging as we require a wide range of effective COVID-19 treatments.We already have two treatments that are proven to reduce hospital stays and mortality– dexamethasone and remdesivir. But more are needed!
So before detailing these breakthroughs, this will be my last piece before what is traditionally known as the ‘so-called’ myth of the summer holidays. Like many people we have had to deny ourselves the compulsion of ‘getting away’ after lock-down and leaving these fair shores.
But where do you go? It poses a dilemma. Do we fly? Would the airline be in technically bankruptcy? What would airports be like? Would there be a second wave home or away? What quarantine measures are in place? Many of us have processed the same thoughts.
To avoid airports, we have thought of driving to France, perhaps to Brittany. Even this is fraught with complications as France is now experiencing a series of fresh outbreaks. Health Minister Oliver Véran has publicly warned that France has between 400 and 500 active clusters of COVID-19 (as July 23rd). Brittany now has an R value of 2.6 and in Marseille and Nice is reportedly at 1.55.
So, that put an abrupt end to our cunning plan. We made the decision to therefore stay at home, but it is refreshing to hear of progress regarding our fight against COVID-19.
The coronavirus vaccine candidate being developed by the University of Oxford it would seem is safe and does stimulate the immune system. This is according to preliminary results from trials involving 1077 volunteers.
The Oxford Vaccine Candidate
The Oxford vaccine, (ChAdOx1 nCoV-19) is made up of a weakened version of a common cold virus called an adenovirus that commonly infects chimpanzees. This virus was then genetically altered so that it was unable to replicate in humans.
The researchers then added genes that sequence ‘spike’ proteins (called peplomers) from COVID-19: these are the essential parts of the coronavirus that allows it to infect human cells.
In fact, the spike protein fringe that encircles the coronavirus gives it its name from the Latin word ‘corona’ (which means ‘crown’). The principle is that the vaccine will teach human immune cells to recognise the spike protein, so that if a person gets exposed to the coronavirus, their immune system can destroy it.
The research team at Oxford started testing the vaccine on people in April and published early results from their phase 1 trial and still-ongoing phase 2 trials on July 20th in the Lancet as we mentioned earlier.
Oxford Vaccine Candidate Phase I & II Trial Results
In these trails they tested the safety and immune response of the Oxford vaccine on a total of 1,077 participants between the ages of 18 and 55 with no prior history of COVID-19 in five hospitals. No serious side effects were found, although 70 per cent of people developed a fever or headache which could be managed with simple analgesics such as paracetamol.
Half of the participants received the Oxford vaccine and the other half a different vaccine that acted as a control, this was a meningococcal vaccine. Obviously, they did this so participants would not be able to guess whether they received the actual vaccine or the control, because both might cause similar side effects.
Blood samples were taken from each participant on the same day they were given the Oxford vaccine and then again 28 days later. This will also be eventually followed up at 184 days and 364.
The team found that the Oxford vaccine produced antibodies that can not only latch onto the virus but also block it from infecting cells — in 91% of the participants who received a single dose of vaccine and 100% in those who received two doses.
The vaccine also raised the level of T-cells that recognise COVID-19. T-cells are a group of white blood cells that could directly kill the virus or stimulate other parts of the immune system.
Sarah Gilbert a co-author of the study, a professor of Vaccinology at the University of Oxford, said in the statement. ‘There is still much work to be done before we can confirm if our vaccine will help manage the COVID-19 pandemic, but these early results hold promise. As well as continuing to test our vaccine in phase 3 trials, we need to learn more about the virus — for example, we still do not know how strong an immune response we need to provoke to effectively protect against SARS-CoV-2 infection.’
The authors also noted some other limitations. More research is still required to replicate the results in different subsets of people (91% of the participants in the trail were white and the average age was 35 years old).
The study is now also recruiting volunteers for ongoing phase 2 and phase 3 trials in the U.K., Brazil, and South Africa. These larger trials are clearly necessary so it can be determined if the vaccine can then be effective in stopping people becoming ill in practice rather than principle.
These trials will involve 10,000 people in the UK, 30,000 people in the US, 2,000 in South Africa and 5,000 in Brazil. These studies would deliberately expose healthy volunteers to the coronavirus after they have been given the experimental vaccine!
New Nebuliser Treatment based on Interferon beta SNG001
Then there is our nebuliser treatment. Southampton, UK-based company Synairgen announced positive results from its small clinical trial of SNG001, which is an inhaled formulation of interferon beta (or IFN beta), in 110 hospitalised COVID-19 patients.
The results demonstrated that the risk of developing severe disease (requiring ventilation or resulting in death) during the treatment period of 16 days was significantly cut by 79% for patients receiving SNG001. This was compared to patients who received placebo. Data also showed that patients who received SNG001 were more than twice as likely to recover. What is not to like!
SNG001 or Intferon beta has an interesting history as it was once licensed by AstraZeneca in 2016 but eventually abandoned as an asthma therapy. So, it has been repurposed. Interferon beta has been widely used in injectable forms and as a scientific concept its use is well understood.
Interferons (or IFNs) are members of the cytokine family which are extracellular signalling proteins. The cytokine family comprises several substances, such as interferons or interleukins, and various growth factors, which are secreted by certain cells of the immune system which then serve to influence other cells.
They do not directly inhibit a virus’s multiplication, but they stimulate infected cells and those nearby to produce proteins that prevent the virus from replicating within them.
This small-scale limited phase 2 trial, at face value at least, looks impressive although the study, along with its data, has yet to be officially published.
Professor Stephen Holgate one of Synairgen’s co-founders commented: “Recognising that SARS-CoV-2 is known to have evolved to evade the initial antiviral response of the lung, our inhaled treatment of giving high local concentrations of interferon beta, a naturally occurring antiviral protein, restores the lung’s ability to neutralise the virus, or any mutation of the virus or co-infection with another respiratory virus such as influenza or RSV, as could be encountered in the winter if there is a resurgence of COVID-19.”
Another point in its favour is that delivering interferon directly to lungs via a nebuliser is crucial because it is not possible to inject a high enough dose without serious side effects.