The cost per dose is less than $1, much less than, for example, the cost per dose of the Pfizer and Moderna vaccines used in the United States.
The vaccine targets part of the spike protein of the SARS-CoV-2 virus.
In animal studies, the vaccine protected pigs against two diseases caused by two types of coronavirus, SARS-CoV-2 and swine epidemic diarrhea virus.
The scientists developed the vaccine to follow a part of the coronavirus spike protein called the “viral fusion peptide,” which is essentially universal among coronaviruses.
“In all the sequences that have been obtained so far for SARS-CoV-2, this region of the spike protein shows no changes at all,” notes one of the study authors, University of Virginia professor Steven Zeichner.
The researchers genetically altered the E. coli bacteria by removing the pathogenic parts and adding the coronavirus target protein to the bacterial surface.
The inactivated bacteria are then recognized by the immune system, which establishes protection.
Vaccines based on inactivated bacteria have been around for a century and do not require ultra-deep freezing.
It is noted that so far the vaccine has not prevented infection, but it has protected pigs from developing severe symptoms and has activated the pigs’ immune system to respond more vigorously to infection.
The researchers now need to adjust the best dose, the best route of vaccine administration and the best schedule, Zeichner said. They also want to experiment with other substances that can be added to further enhance the immune response.