US researchers have developed a novel, low-cost DNA-based vaccine that may not only provide protection against existing variants of coronavirus, but also against its future strains. The vaccine, which will cost about $1 a dose, has shown promising results in early animal testing, said the team from University of Virginia and Virginia Polytechnic Institute and State University. “Our new platform offers a new route to rapidly produce vaccines at very low cost that can be manufactured in existing facilities around the world, which should be particularly helpful for pandemic response,” said Steven L. Zeichner from the UVA Health. The study is detailed in the journal PNAS.
Zeichner’s new vaccine-production platform involves synthesizing DNA that directs the production of a piece of the virus that can instruct the immune system how to mount a protective immune response against the virus.
That DNA is inserted into another small circle of DNA called a plasmid that can reproduce within bacteria. The plasmid is then introduced into bacteria, instructing the bacteria to place pieces of proteins on their surfaces. The technique uses the common bacteria E. coli.
To produce the vaccine, the bacteria expressing the vaccine antigen are simply grown in a fermenter, much like the fermenters used in common microbial industrial processes like brewing, and then killed with a low concentration of formalin.
“Killed whole-cell vaccines are currently in widespread use to protect against deadly diseases like cholera and pertussis. Factories in many low-to-middle-income countries around the world are making hundreds of millions of doses of those vaccines per year now, for a $1 per dose or less,” Zeichner said.
“It may be possible to adapt those factories to make this new vaccine. Since the technology is very similar, the cost should be similar too.”
The entire process, from identifying a potential vaccine target to producing the gene-deleted bacteria that have the vaccine antigens on their surfaces, can take place very quickly, in only two to three weeks, making the platform ideal for responding to a pandemic, the researchers said.