Researchers who set out to examine how SARS-CoV-2, the virus responsible for COVID-19, evolved to evade the human immune system have inadvertently added fuel to the debate over whether mass vaccination may have prolonged the pandemic.
A peer-reviewed study, published this month in the journal Scientific Reports, hypothesized that SARS-CoV-2’s pathway to infecting humans shifted over time. Understanding that process will help scientists develop treatments for all future variants of the virus, the authors said.
Using public datasets consisting of blood and nasal samples from over 500 people, split into COVID-positive and control groups, the researchers found that the original strain of the SARS-CoV-2 and early variants “primarily affected pathways related to viral replication” — the process through which viruses insert their genetic material into host cells, co-opting those cells to create new viral particles.
These earlier strains of the virus led to more changes in gene expression — the process through which cells convert instructions in our DNA into a functional product, such as a protein. This, in turn, led to more severe COVID-19 infections.
However, later strains of SARS-CoV-2, such as Beta and Omicron, “showed a strategic shift toward modulating and evading the host immune response,” but also resulted in milder infections for most people.
According to TrialSite News, this is a “striking evolutionary shift in how SARS-CoV-2 interacts with the human body,” suggesting that newer variants “may be optimized for immune evasion.”
Hellbound and Down 