Beware of COVID-19 fatigue: the BA.2 subvariant remains dangerous, say researchers

Despite public fatigue with health measures and repeated protective advice, the BA.2 subvariant is a very real threat that must 'absolutely' be taken seriously, experts warn.

"BA.2 is a significant health risk, just as BA.1 was a few months ago when it killed 7,000 people across the country," warns CoVaRR-Net, a network of interdisciplinary researchers established to contribute to the Government of Canada's overall strategy to address the threat of newly emerging variants of SARS-CoV-2, in an email.

BA.2 is highly transmissible (moreso than BA.1, the first Omicron subvariant, which was dominant from December to February of this year), because it is able to infect and spread more easily in our cells.

Because of this high transmissibility and rapid spread at a time when public health measures have been scaled back, the CoVaRR-Net website states, "BA.2 is fuelling the sixth wave of the pandemic and increasing both the health risks to Canadians and the need for thoughtful and appropriate protective measures.

While it may appear that the BA.1 and BA.2 subvariants are more benign than the Delta variant and that the health risks associated with COVID-19 are decreasing or have passed, CoVaRR-Net adds, "BA.2 remains a serious threat that results in serious illness, hospitalizations and deaths among Canadians every day."

"I think there is COVID fatigue and people are underestimating the impact that BA.2 can have on health," warned Denis Leclerc, a virologist at the Centre de recherche du CHU de Québec who is a member of CoVaRR-Net.

The usual advice remains in order with the arrival of the Easter and Passover weekend, during which family gatherings will increase, Leclerc added.

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Beta, Delta, Omicron, BA.2 and now the XE variant (which we don't know much about yet, except that it's a hybrid of the BA.1 and BA.2)... the list goes on and on and the coronavirus, as we have often heard, 'is here to stay.'

The vaccines that we currently have to fight it will never succeed in making it disappear entirely, since they train the immune system to recognize the spike protein on its surface. It is this protein that mutates and gives the virus its new identities, allowing it to at least partially escape counter-attack.

In order to hope to defeat it once and for all, we must change our strategy, said Leclerc.

"We absolutely have to start thinking about the emergence of new vaccines that will be better adapted to the strains that are circulating now, much like we do with the flu virus," said Leclerc. "The flu vaccine contains four different strains of the flu virus to protect us. We may need to think about developing vaccines that will contain several different proteins to make sure we have a broader spectrum of protection against coronaviruses."

With that in mind, Leclerc and his colleagues are currently working on developing a vaccine that would teach the immune system to recognize a protein called nucleocapsid.

Without this protein, Leclerc said, the coronavirus would be unable to replicate. It is therefore improbable, in an evolutionary and survival context, that this protein would eventually mutate.

The vaccine from the Quebec firm Medicago, which was approved in Canada but rejected by the World Health Organization because the biomedical company is minority-owned by cigarette maker Philip Morris, targets nucleocapsid in part.

"It's going to give us vaccines that are going to give protection against all the strains that can emerge," Leclerc said. "There's a lot of proof of concept ... on the use of nucleocapsids in vaccination, but it's not something that has been commercialized or used extensively in humans.

"But I think we're there with the coronavirus. It's an approach that's really worth exploiting because, basically, it's what would get us out of this pandemic," he said.

- This report by The Canadian Press was first published in French on April 15, 2022