May 28, 2023

Omicron subvariants behind South Africa surge detected in Canada

The WHO lamented that two years on the virus is still evolving and surging in some parts of the world

The WHO lamented that two years on the virus is still evolving and surging in some parts of the world – Copyright AFP Jung Yeon-je

Two new Omicron subvariants driving a surge of COVID-19 infections in South Africa have been detected in Canada.

Nation World News is reporting that a Public Health Agency of Canada (PHAC) spokesperson confirmed they are aware of three BA.4 cases in Canada, and one of BA.5.

“The Government of Canada has a strong monitoring program in place with the provinces and territories to identify COVID-19 variants in Canada, including the Omicron variant of concern and its sub-lineages,” they said. “Scientists are looking for signs that Omicron sub-lineages such as BA.4 and BA.5 change disease severity, transmissibility or impacts the effectiveness of diagnostic tests, vaccines or treatments for COVID-19.”

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 Most of those cases have been detected in South Africa.

As part of their evolution, viruses will mutate over time, creating subvariants with a different genetic makeup than the original variant but still with a common origin. The World Health Organization (WHO) says BA.4 and BA.5 have acquired a few additional mutations that may impact their characteristics.

The latest government data shows the highly-transmissible BA.2 Omicron subvariant is currently the most common cause of COVID-19 infection in the country, according to CTV News.

Virus case numbers in India have jumped in recent weeks due to the highly infectious Omicron strain – Copyright AFP Punit PARANJPE

Even with BA.2 being the dominant cause of COVID-19 infection in Canada, the Public Health Agency of Canada, along with national and international experts, are actively monitoring and evaluating the BA.4 and BA.5 sub-lineages and the associated studies,” the PHAC said.

One early study, which has not been peer-reviewed, suggests BA.4 and BA.5 “show potential higher transmissibility over BA.2” and could also possibly evade antibodies created from previous Omicron infection.

Another study done last month that is awaiting peer review suggests that although vaccination “would likely offer good protection against severe disease,” the two subvariants’ ability to dodge antibodies could “result in a new infection wave.”

And this is apparently happening in South Africa, WHO director-general Tedros Adhanom Ghebreyesus said during a media briefing on Tuesday. “Omicron, and specifically BA.4 and BA.5, is driving the upsurge in South Africa, while BA.2 is dominant worldwide.”

“The BA.4 and BA.5 subvariants were identified because South Africa is still doing the vital genetic sequencing that many other countries have stopped doing,” Ghebreyesus said earlier in May.

Last week, more than 32,000 new infections were reported in South Africa, representing a 67 percent increase from the week before, according to Global News. Globally, the number of cases and the number of countries reporting the detection of these subvariants are rising, the UN health agency said in its weekly update.