A pioneering piece of technology that is being used in Covid-19 vaccines from Moderna and Pfizer/BioNTech originated in London around 50 years ago.
Biochemist Gregory Gregoriadis, professor emeritus at University College London, was one of the two scientists who discovered that encasing vaccines within tiny spherical bubbles of fat – known as liposomes – could increase their effectiveness by producing more antibodies.
He and the late Anthony Allison, who was working at the Clinical Research Centre at Northwick Park Hospital in Harrow, published their findings in a Nature paper in 1974.
Prof Gregoriadis, 86, told the PA news agency: “I started this work in 1971.
“We decided to find out if we could trap a vaccine using the liposomes and see what happens.
“What we found was that by putting vaccines into liposomes, we had a much greater antibody response.”
Inside the human body, there are small packages of fat bubbles that transport nutrients as well as waste.
This gave scientists the idea of using liposomes as a way to deliver not only vaccines, such as hepatitis A and influenza, but also life-saving drugs.
Prof Gregoriadis said there are now more than 25 drugs using lipid nanoparticles, an offshoot of the liposome technology, many of which are anti-cancer medicines.
He said: “Liposomes are considered to be the most successful drug and vaccine delivery system, with life-saving products already marketed worldwide, and with many more in clinical trials.
“LNPs (lipid nanoparticles) are a welcome offshoot of liposomes as they introduce new technology and new possibilities without losing the many advantages of the liposomal system.”
This lipid nanoparticle technology also underpins both the Pfizer/BioNTech and Moderna vaccines that are being used in the global battle against Covid-19.
Sars-Cov-2, the virus that causes Covid-19, is studded with “spike proteins” that it uses to enter human cells.
These spike proteins are a target for all potential Covid-19 vaccines.
The Moderna and Pfizer vaccines use synthetic messenger RNA (mRNA), a genetic material that contains information about the spike protein.
The mRNA provides the body with instructions to produce a small amount of this protein which, once detected by the immune system, leads to a protective antibody response.
However, mRNA is extremely fragile and would be destroyed by the natural enzymes if it were injected directly into the body.
Hence to protect the vaccine, Moderna and Pfizer have wrapped the mRNA in lipid nanoparticles, which also act as an adjuvant – a substance which enhances the body’s immune response to an antigen.
Prof Gregoriadis, who received the first dose of the Pfizer vaccine last week, said he looks forward to spending more time with his family and grandchildren once the lockdown restrictions are lifted and most of the population has been immunised.
He said he found it “very satisfying” that the work he and his colleague carried out half a century ago has played a role in the development of coronavirus vaccines.
Prof Gregoriadis told PA: “When you are a scientist, you tend to ignore the emotional part of it.
“I’m proud that the vaccine technology has its origins in the work we first carried out in London 50 years ago.”