Targets for corona vaccine identified by scientists

New Delhi, June 09: Scientists have identified regions of the SARS-CoV-2 virus that causes COVID-19 to target with a vaccine, by harnessing tools used for the development of cancer immunotherapies.

The researchers at Children's Hospital of Philadelphia (CHOP) in the US employed the same approach used to elicit an immune response against cancer cells to stimulate an immune response against the novel coronavirus.

Using this strategy, the researchers believe a resulting vaccine would provide protection across the human population and drive a long-term immune response.

"In many ways, cancer behaves like a virus, so our team decided to use the tools we 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," said John M Maris, a pediatric oncologist at CHOP, and a professor at the University of Pennsylvania.

"We think our approach provides a roadmap for a vaccine that would be both safe and effective and could be produced at scale," said Maris, senior author of the research published in the journal Cell Reports Medicine.

The COVID-19 pandemic has led to an urgent need for the development of a safe and effective vaccine against SARS-CoV-2, the virus that causes the COVID-19 disease, the researchers said.

An optimally designed vaccine maximises a long-lasting immune response, while minimising adverse reactions, autoimmunity, or disease exacerbation, they said.

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.

The researchers 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.

The team will now test various combinations of a dozen or so of these sequences in mouse models to assess their safety and effectiveness.