Plants have been “hijacked” to make polio vaccine in a breakthrough with the potential to transform vaccine manufacture, say scientists.
The team at the John Innes Centre, in Norfolk, says the process is cheap, easy and quick.
As well as helping eliminate polio, the scientists believe their approach could help the world react to unexpected threats such as Zika virus or Ebola.
Experts said the achievement was both impressive and important.
The vaccine is an “authentic mimic” of poliovirus called a virus-like particle.
Outwardly it looks almost identical to poliovirus but – like the difference between a mannequin and person – it is empty on the inside.
It has all the features needed to train the immune system, but none of the weapons to cause an infection.
The scientists hijacked a relative of the tobacco plant’s metabolism to turn its leaves into polio-vaccine “factories”.
First, they needed to create new instructions for the plant to follow.
The starting material was the genetic code for making the outer surface of poliovirus.
It was enhanced by combining it with material from viruses that naturally infect plants.
The new instructions were then put into soil bacteria, which were used to infect tobacco.
The infection took hold, the plants read the genetic instructions and started making the virus-like particles.
Infected leaves were mixed with water, blended, and the polio vaccine was extracted.
The virus-like particles prevented polio in animal experiments, and an analysis of their 3D structure showed they looked almost identical to poliovirus.