Imperial College team work out how to keep RNA coronavirus vaccine in the fridge rather than -70C

A British team at Imperial College has worked out how to keep an RNA vaccine, similar to the leading Pfizer/BioNTech coronavirus candidate, stable in the fridge.

The research is significant because one of the leading obstacles to a full-scale roll-out of the Pfizer vaccine is the fact that it needs to be deep frozen at -70C.

Earlier this week, scientists and governments around the world hailed results from Pfizer and BioNTech, which showed that its vaccine prevented disease in 90 per cent of its trial participants, as the light at the end of the tunnel for the pandemic.

But there are concerns that the challenges in distribution may be insurmountable, particularly in hotter countries with less developed infrastructure. Deep freezing a vaccine requires dry ice or specialised containers four times colder than normal freezers.

However, new research from the team at Imperial, who are also working on a coronavirus vaccine using similar technology, said they have been able to adapt their formula in order to make it stable at higher temperatures.

One formulation has remained stable in the fridge for five months, the team's leader, Professor Robin Shattock, told The Telegraph. 

"We are already looking at how to make our vaccine stable at refrigerated temperatures, and it is absolutely possible," he said.

"We have started monitoring it in our lab, and we already have a research formulation that's been stable at a refrigerated temperature for five months. We still need significant investment to get it to a clinical product."

The Imperial team's RNA vaccine uses similar emerging technology as the Pfizer vaccine, as do a number of other candidates around the world. 

These vaccines introduce messenger RNA into the body via lipid particles, or fats, containing genetic code instructing the body's cells to make the spike protein of coronavirus, the element that helps it attach to human cells.

The immune system then reacts to the invader, and produces antibodies and t-cells that recognise and react to the real thing if a person later gets infected.

The team at Imperial have adapted an element of their formulation, called the buffer, to ensure the stability of the RNA housed within the fat droplets at higher temperatures.

Pfizer has said it is also working on making its vaccine more stable, but it does not expect to deliver anything before 2022. It has suggested that a powdered version of the vaccine could be one option.

CureVac, another manufacturer developing an RNA vaccine, said on Thursday that its candidate could also be kept at normal fridge temperatures of around 5C for several months, and for 24 hours at room temperature. CureVac began stage two clinical trials of its vaccine in September.

Professor Shattock said that the fact that the Imperial team was behind in terms of clinical trials - they are due to start in January - meant they had more time to adapt their vaccine rather than focusing on being first.

"The priority has been who is going to be first, but whether our vaccine is successful or not, this shows that there will be better products over time," he said.

"This first vaccine looks encouraging [the Pfizer/BioNTech candidate] but is still quite complex to roll out - and one of the reasons for this is they've moved really fast, they haven't spent time optimising things. They said let's get the fastest solution, with the biggest volume, out as quickly as possible. But for us, because we are behind, we are already looking at refrigerated temperatures."

He said, with sufficient funding for more research, their vaccine could be ready for use at these temperatures by the middle of next year.

However, funding remains a challenge for the team, which Professor Shattock described as operating on a "wing and a prayer". It has not yet partnered with a large pharmaceutical company, with the deep pockets necessary to speed up research in areas like this. Many have their own vaccine candidates.

Imperial has had some funding from the UK government for the vaccine research, around  £7m of which is committed.

By contrast, Germany's government gave BioNTech  £336m in funding in September.

The British government has focused its attention - and money - on the candidate being developed by Oxford University and AstraZeneca, which uses more traditional vaccine technology. It is also due to report results soon.

Protect yourself and your family by learning more about Global Health Security