An infectious disease expert believes the global response to the COVID-19 pandemic has been an "unmitigated disaster" and the rapid spread of the Omicron has made another variant a near certainty.

"The whole world is a playing field for the virus right now," Dr. Madhukar Pai, an expert in infectious diseases at McGill University, told CTV National News.

Pai warned that "there will be mutations" after allowing millions of unvaccinated people across the globe to become infected. He says they're now "incubating" billions of different virus particles.

"There is no saying what that next variant might look like," Pai says. "We just lucked out with Omicron."

The solution to slowing the spread of COVID-19 remains the same as it's always been, according to Pai, and that's ensuring global equity and access to vaccines.

However, Pai isn't particularly optimistic about an improvement in global coordination, saying that most world leaders have proven "simply incapable" of looking outside "national boundaries."

"Each country has gone isolationist," he warned. "Each country has bought into populism as a way forward."

Watch more of this interview by clicking the video at the top of the article.