New vaccine concept against SARS-CoV-2 successfully tested
Researchers at the University of Basel have developed a new approach for a vaccine against COVID-19. This vaccine is based on a modified coronavirus that can enter body cells and trigger an effective immune response but cannot multiply in the body. In animal studies, the vaccine effectively protected against the disease and even prevented virus transmission. Clinical trials in humans are to follow.
22 May 2023 | Angelika Jacobs
Although safe and effective COVID-19 vaccines have been available since early 2021, SARS-CoV-2 continues to spread, with new variants continuously emerging. In some regions, the population lacks access to vaccines; in others, there is a lack of confidence in the novel mRNA vaccines. New vaccines that are easy to store and administer and that build up effective immune protection would be an important step toward keeping the SARS-CoV-2 coronavirus at bay in the long term.
Researchers led by Professor Thomas Klimkait of the Department of Biomedicine at the University of Basel, in collaboration with the company RocketVax, are now presenting a vaccine concept that could lead to a new generation of vaccines against SARS-CoV-2. This concept can also be rapidly adapted to new variants and even to other viruses. Their promising results are now being submitted to a peer-reviewed journal for publication and are accessible on a preprint server.
Vaccine virus incapable of replication
“Single-cycle virus” is how the researchers describe the principle of their novel vaccine. The vaccine is based on a specially adapted version of the virus that can be produced in the laboratory. In cells of the vaccinated person, however, the single-cycle virus cannot replicate further after the initial entry.
“From a technical point of view, we introduce the modified virus genome as several pieces into the production cell line, because that is easier to produce and sneak in.” Inside the cell, repair enzymes ensure that the pieces of virus genome are put back together to form a whole. “This also means, for example, that we can easily exchange the section containing the blueprint for the spike protein if a new variant emerges with new mutations.”
No re-conversion to a live virus
It is impossible for the missing gene, corresponding to the viral envelope building block, to return, Klimkait emphasizes. “The envelope protein gene is located in the genetic material in the nucleus of the production cell. The virus genome, on the other hand, always remains outside the nucleus – so they never meet, and the virus genome cannot restore itself to the original version.”