BA.4, BA.5 in Canada: What we know about the 2 new Omicron subvariants

BA.4 and BA.5 can dodge antibodies from earlier infection well enough to trigger a new wave, according to South African scientists.

The World Health Organization (WHO) is closely monitoring two new COVID-19 subvariants of Omicron, the highly transmissible variant of concern now dominant around the world.

Since January, more than 300 cases of the BA.4 and BA.5 sub-lineages have been reported in several countries, according to data by cov-lineages.org. Most of those cases have been detected in South Africa.

As of May 3, Canada had detected three cases – two of BA.4 and one of BA.5, the Public Health Agency of Canada (PHAC) told Global News on Friday.

“As with all new sub-lineages of COVID-19, scientists from the Public Health Agency of Canada (PHAC), along with national and international experts, are actively monitoring and evaluating the BA.4 and BA.5 sub-lineages and the associated studies,” said PHAC spokesperson Anne Genier in an emailed statement.

WHO began tracking BA.4 and BA.5 in mid-April. They are in addition to previously discovered subvariants BA.1 and BA.2, the latter of which is dominating COVID-19’s global spread.

As part of their evolution, all viruses mutate over time and have subvariants that have a different genetic makeup than the original variant but a common origin.

The WHO says BA.4 and BA.5 have acquired a few additional mutations that may impact their characteristics.

Here is what we know so far about these subvariants.