Two weeks ago, the highly contagious BA.2 sub-variant of the Omicron strain had been detected in about 10 per cent of COVID-19 cases in Quebec.
On Wednesday, interim public health director Luc Boileau said BA.2 now accounts for half of all confirmed cases in the province. Its rapid rise is similar to surges seen in territories like Denmark and the United Kingdom, leading to concerns it could generate a sixth wave.
What is BA.2?
It’s a strain of the Omicron variant that was first detected in the Philippines in November and is believed to be 30 to 50 per cent more transmissible than the original Omicron.
The first cases of BA.2 in Quebec were detected in late January. Initially its spread was slow, but it has picked up steam in March.
Health authorities have predicted the effects of the sub-variant will be dampened due to high levels of immunity through prior infection and vaccination (87 per cent of Quebecers five and older are fully vaccinated), but some experts worry that Quebec’s easing of health restrictions and the fact that immunity levels wane with time could leave citizens vulnerable.
“I think we should be very concerned,” said Dr. André Veillette, director of the Molecular Oncology Research Unit at the Montreal Clinical Research Institute. “It’s a highly contagious virus, one of the most contagious that we know of, and it’s obviously spreading.”
Is it more dangerous than its predecessor?
Judging from studies in other parts of the world, this sub-variant doesn’t appear to cause more severe forms of the illness. But because it’s more transmissible, it has the potential to cause an upsurge in overall cases, which could lead to more hospitalizations.
The World Health Organization reported this week that BA.2 has led to an increase in cases in 18 countries, many of them in western Europe, which is typically a few weeks ahead of Canada in terms of COVID-19 progression. In most of those countries, while BA.2 contributed to a rise in cases, there was no significant increase in hospitalizations or deaths, due to high vaccination rates and prior infections.
The same cannot be said of the United Kingdom, where a surge in cases was followed by a 35 per cent rise in hospitalizations. In Scotland (whose population is 5.5 million), cases have risen for the last seven weeks. In the last week alone, it’s estimated that more than 370,000 people were infected, and Scotland is on the verge of reaching a new high in COVID-19 hospitalizations.
In other countries, the BA.2 surge has already peaked and is starting to diminish.
WHO officials said the surge has mostly been due to governments easing pandemic restrictions too quickly, as opposed to the sub-variant.
Boileau said Quebec’s slight increase in cases and hospitalizations over the last few days, following weeks of decline, was mainly due to its relaxation of health measures, and had been expected. The slight rise is not necessarily indicative of a sixth wave, he said.
Does prior infection or vaccination provide good protection?
Initial studies out of the UK indicate vaccinated people infected with Omicron have high levels of antibodies that likely protect against BA.2, the New York Times reported, and that vaccines appear to protect as much against BA.2 as they did against the original Omicron .
But scientists caution the effect of vaccines and prior infection wanes with time. “This is why it’s so important for people to get a third dose if they haven’t already, and for children (age five to 11) to get their second doses,” Veillette said. (Roughly 52 per cent of Quebecers five and older are considered “fully vaccinated with an additional dose,” according to the Public Health Agency of Canada.)
Veillette applauded Quebec’s announcement Wednesday that it will make a fourth dose available for those over 80 and others who are more vulnerable.
What can people do to protect themselves?
Veillette’s main concern is that many will take the government’s relaxation of health measures as a sign “they can do whatever they want.” The virus is progressing, he said, and the best way to limit it is through individual protective measures, including wearing a good mask, getting a booster shot and opening windows.
“I think if we all adopt responsible behavior, we can significantly diminish the amplitude of the virus and transform a possible wave into a wavelet,” he said.
Protective measures like wearing a mask will ensure that even if one becomes infected, it will be with less of the virus. Such measures will also limit the chances of transmitting the virus to the vulnerable who are most at risk of hospitalization and death.
“It’s not just about protecting oneself,” Veillette said. “It’s about protecting others.”
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COVID updates for Thursday, March 24
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