The scientists tried to understand if hosts, that is, humans infected by the virus, react differently to different SARS-CoV-2 variants, a release from the premier research institution said. “In the last almost three years, there have been many SARS-CoV-2 variants spreading across the world. But their outcome has varied greatly, with the Delta variant being the deadliest,” it said.
Five different SARS-CoV-2 variants were chosen and scientists studied how the human immune system responded to them. The variants included Alpha, Delta, and three others that emerged before Alpha. In the study published in Microbiology Spectrum journal, the researchers found that the immune system could not produce the defence molecules against the Delta variant as effectively as the other variants. While infection due to the other four variants alerted the immune system quickly, the Delta variant could silently replicate in the host cells.
“We have identified that molecular mechanisms regulating the host immune response have not been as potent against the Delta variant of SARS-CoV-2. This also includes the production of interferons, immune molecules often used for antiviral therapies. The study hints at why the Delta variant could spread more easily,” said Dr. Krishnan Harshan, the lead investigator in this work. He added that the study also helps understand how viruses evolve with changing effects on human hosts.