How is the Omicron variant different and why are scientists so concerned?

CANMORE, ALTA. -- Scientists around the world are racing to learn more about the newly discovered B.1.1.529 coronavirus variant, now known as Omicron, to see how it compares to other variants of concern. The important questions – like how transmissible it is, how good it is at evading immunity from vaccines or past illness, and whether it causes more severe illness – remain to be answered. While some scientists say it will be weeks before we get a clear picture of how Omicron will impact the pandemic, the World Health Organization (WHO) said Wednesday it expects to have more information on the transmissibility of the variant within days.. What we do know about this variant is that it contains more than 30 mutations in the spike protein, which allows it to bind to human cells and gain entry to the body – a factor that has elevated concerns for some scientists.

WHAT IS A MUTATION?

First, it’s important to remember that mutations to SARS-CoV-2, the virus that causes COVID-19, have been expected since the early days of the pandemic. That’s because mutations always arise as viruses spread – it’s how they ensure their own survival. According to researchers from Yale University, SARS-CoV-2 gains access to our cells using its “corona” – a layer of protein spikes that fit into our cells like a lock and key – where it makes copies of its genomes. But during that process, errors are inevitably introduced into the code, causing a mutation or variant.

Sometimes those mutations are harmless. But other times, like in the case of the Delta variant, the virus can change to become more transmissible or cause more severe illness. “What we have seen with other viruses is, over time, they mutate in various ways. And one of the ways that they can mutate is to actually get a little bit less severe because there’s a bit of a fitness cost to the virus,” Dr. Susy Hota, infectious disease expert at Toronto’s University Health Network told CTV’s Your Morning Wednesday.

“If it starts to kill off its hosts a little bit too early, it just won’t replicate. And that’s the goal of a virus, is to make more copies of itself and persist over time.”

Hota notes that COVID-19 has held its advantage with previous variants because it tends to have infections that last for quite a while, giving it plenty of opportunity to spread from person to person.