Most of the vaccines used today against the coronavirus work by using parts of the virus’ so-called spike protein to activate the body’s immune system. A concern with these is that the spike protein mutates often and can thus make the vaccine less effective.
Researchers at the Karolinska Institute are therefore looking into whether a so-called DNA vaccine, which is not as sensitive to mutations, could be effective. What is now being studied contains several parts of the virus, including ones that do not mutate at the same rate.
Wider protection
— The theory is that this type of vaccine can provide broader protection and even be effective against any new coronaviruses that may come in the future, says Ali Mirazimi, adjunct professor at the Karolinska Institute and co-author of the study.
In the study, as published in the journal EMBO Molecular Medicine, the researchers have tested the DNA vaccine on mice. They saw that the mice that received the vaccine were more protected against severe infection with the beta variant of sars-cov-2 than non-vaccinated mice.
The current vaccine consists of DNA sequences that cause the cells to start producing certain specific proteins. The researchers used parts of the spike protein from three different variants of the coronavirus plus two other viral proteins that are more stable. That the vaccine targets parts of the virus that do not mutate so easily could mean that it provides broader protection.
Experiment on humans
— The idea is that it could be used to give top-up doses that hopefully protect longer than today’s vaccine, says Ali Mirazimi.
The researchers have submitted an application to the Swedish Medicines Agency to start trials on humans, a so-called phase 1 study.
— As soon as we get an answer, we are ready to start testing, says Ali Mirazimi.
The vaccine has been developed at the Karolinska Institute in collaboration with the Karolinska University Hospital and the Royal Institute of Technology in Stockholm.
Two of the researchers behind the study are Matti Sällberg and Lars Frelin, who are founders and co-owners of Svenska Vaccinfabriken Produktion, which owns patent applications for the vaccine.