US researchers identify targets for Covid-19 vaccine
Researchers in the US have identified regions of the novel coronavirus (SARS-CoV-2) to target with a vaccine, by harnessing tools used for the development of cancer immunotherapies.
Using this strategy, the researchers believe a resulting vaccine would provide protection across the human population and drive a long-term immune response, the study, published in the journal Cell Reports Medicine, said.
In many ways, cancer behaves like a virus, so the research team decided to use the tools they developed to identify unique aspects of childhood cancers that can be targeted with immunotherapies and apply those same tools to identify the right protein sequences to target in SARS-CoV-2.
"By adapting the computational tools developed, we can now prioritise viral targets based on their ability to stimulate a lasting immune response, predicted to be in the vast majority of the human population," said senior author John M Maris from the University of Pennsylvania.
"We think our approach provides a road map for a vaccine that would be both safe and effective and could be produced on a scale," Maris added.
To increase the likelihood that a vaccine is both safe and effective, the research team prioritised parameters in identifying regions of the virus to target.
They looked for regions that would stimulate a memory T-cell response that, when paired with the right B cells, would drive memory B cell formation and provide lasting immunity and do so across the majority of human genomes.
They targeted regions of SARS-CoV-2 that are present across multiple related coronaviruses, as well as new mutations that increase infectivity, while also ensuring that those regions were as dissimilar as possible from sequences naturally occurring in humans to maximise safety.
The researchers propose a list of 65 peptide sequences that, when targeted, offer the greatest probability of providing population-scale immunity.
As a next step, the team is testing various combinations of a dozen or so of these sequences in mouse models to assess their safety and effectiveness.
"Our approach, if successful, could lead to protection against not only SARS-CoV-2 but also other coronaviruses that might emerge in the future," said study lead author Mark Yarmarkovich.
