Imperial Connection: Imperial's promising candidate Covid-19 vaccine

By Stephen Johns, International Communications Officer, Imperial College London
Shortly after Covid-19 arose this year, researchers around the world – including those from Imperial College London – raced to develop a vaccine for the coronavirus.

Today, vaccine development has moved at an unprecedented pace as compared to before, when vaccines traditionally took about a decade or longer to develop.

At Imperial, its researchers have developed a pioneering technique that allows them to work faster towards developing a vaccine for Covid-19.

Developing a candidate Covid-19 vaccine

In January, Imperial's scientists received the virus' genetic code from partners in China. They then developed a candidate vaccine within 14 days and quickly moved to testing the vaccine in animals.

With this development, the vaccine team was one of two to receive funding from the UK government's Vaccines Taskforce. A few months ago, the first healthy volunteers received the candidate vaccine.

The vaccine has already shown signs of early promise and early results from human trials are expected imminently.

Based at St Mary's Hospital in London, the team is led by Imperial's Professor Robin Shattock, who is the Head of Mucosal Infection and Immunity within the Department of Medicine.

Before Covid-19 first emerged, Prof Shattock was already working on the manufacturing of RNA vaccines to create quicker and more accessible responsiveness to outbreaks of known pathogens, such as flu, and unknown pathogens, called Disease X.

He also warned world leaders at the World Economic Forum in Davos about a year before the start of the coronavirus outbreak, about the challenges of tackling a future pandemic. Then, Prof Shattock urged policymakers, scientists, and funders to 'reimagine the way vaccines are being produced and approved'.

"We have the kind of technology to be able to generate a vaccine with a speed that's never been realised before. Most vaccines are five years in the discovery phase, and at least one or two years to manufacture and get into trials," he added.

How the candidate vaccine works

Imperial's vaccine will train the body's immune system to recognise the virus and help it to defend itself against a future attack. Traditional vaccines are often based on a weakened form of a virus or parts of it, but the Imperial vaccine is based on a new method.

Instead, it is completely synthetic and uses bits of genetic code (called self-amplifying RNA), rather than bits from a real virus.

The Imperial team focused on the part of this sequence that holds the blueprint for the spike protein and was able to recreate the sequence using enzymes in the lab and generate copies of the RNA without the need for animal cells or human stem cells.

The result is short strands of self-amplifying RNA which hold all the information needed to make the spike protein.

These strands are packaged into tiny fat droplets, which form the final vaccine. When the Imperial vaccine is injected (into the arm, or the leg) the cells of the muscle will take up the tiny fat droplets and the RNA they contain.

Once inside the cell, the self-amplifying RNA produces copies itself, which can instruct the cell's own machinery to make the coronavirus protein. The muscle cells will then produce lots of the spike protein – but not the whole virus.

When the immune system comes across these tiny spikes, it recognises them as foreign and creates antibodies.

These antibodies have an important role in fighting viruses as they bind to the spike proteins and may prevent the virus from infecting cells. This process also creates a lasting memory of the spikes so that the body ever comes across them again, it will recognise them and be able to mount a quick response.

Ultimately, the aim of the vaccine is to trick the body into thinking it has already seen the virus and made an immune response, so when you come into contact with it in real life, you should already be immune.

What is the future for Imperial's candidate Covid-19 vaccine?

Imperial's Covid-19 vaccine candidate is being developed and trialled thanks to more than £41 million ($72 million) in funding from the UK government and a further £5 million ($8.8 million) in philanthropic donations. These generous donations come as part of a groundswell of support from Imperial's alumni and donor community, which has seen hundreds pledge a gift to support Imperial's Covid-19 response.

As the vaccine enlists the help of your own body to produce the spike proteins, only a very tiny dose is needed for each person. One litre of the Imperial Covid-19 vaccine could be used to vaccinate two million people. To produce that many doses with a conventional vaccine, you might need 10 thousand litres.

The current trials are the first time the vaccine has been tested in humans and will show what dose is needed to produce an immune response safely. 

Professor Alice Gast, President of Imperial College London, said: "The success of Robin Shattock and his Imperial team in designing a self-amplifying RNA vaccine from a piece of genetic code and moving to human trials within six months is incredible."

If the vaccine proves to be safe and effective, people and populations in the UK and around the world will need access to it.

To make sure this can happen at an affordable price, Imperial has set up a social enterprise, VacEquity Global Health. This will generate a modest revenue to help make sure the vaccine can continue to be produced for years to come, but it will not be marketed as a high-value product.