I think it is great that, during the pandemic, more capacity has been provided for us to monitor genomics and other characteristics of variants of concern. The Public Health Agency of Canada and, indeed, our National Microbiology Laboratory, as well as provincial, territorial and global lab works, have been monitoring the ongoing evolution of the SARS-CoV-2 virus.
The trajectory of viral evolution has changed over time. This is quite interesting. The earlier variants have multiple and often very divergent evolutionary pathways, seeing as there were no vaccines, therapeutics or broad-based population immunity to constrain the range of the mutations. More recently, however, multiple lineages descending from the omicron variant—that very transmissible variant—have begun to develop multiple identical mutations, a phenomenon we're calling “evolutionary convergence”. We have to learn more about that. You may have seen or heard about a variety of these variants, such as BA.2.75, BA.2.75.2, BA.1.1 and BA.4.6. Multitudes of BA.5 descendants have these convergent evolutionary mutations.
The very important thing about monitoring these mutations is that, when there's broad population immunity, it seems to put pressure on the virus to find advantages, such as escaping our existing immunity from infection or vaccines. This broad range of omicron descendants is now being carefully monitored.