Bivalent Vaccines Now Available for Canadians
Evert Lindquist/Victoria News
While Canadians’ vaccine protection wanes, a fall Omicron-fuelled spike in COVID-19 infections and deaths is threatening to overwhelm an exhausted healthcare system. Amid this, provinces and territories are quickly rolling out newly approved bivalent vaccine boosters, targeting the highly contagious Omicron variant.
“It’s essentially two vaccines in one,” Health Canada’s Chief Medical Adviser, Dr. Supriya Sharma explains. Half of the vaccines’ mRNA, which tells human cells to make specific proteins that activate an immune response, targets the original Wuhan strain, while the other half targets Omicron. There are two such vaccines approved for use in Canada.
Approved Sept. 1 for adults 18 and older, Moderna’s bivalent booster targets the no longer dominant original Omicron strain, known as BA.1.
Pfizer’s bivalent booster, which targets the now dominant BA.4 and BA.5 Omicron subvariants, was approved Oct. 7 for use in individuals aged 12 and older. According to Health Canada, as of mid-September, cases of BA.4 and BA.5 made up 97 per cent of new cases.
Moderna submitted its BA.4 and BA.5 bivalent booster for consideration by Health Canada Sept. 12, with no announcement made so far.
Despite BA.1 no longer being dominant, experts are recommending Canadians get whichever bivalent is offered to them first, emphasizing that getting a bivalent booster in the first place is what’s important.
“There’s no strong enough rationale to [...] preferentially recommend one over the other at this stage,” Matthew Miller, from the McMaster Immunology Research Centre, told CBC News.
Based on clinical trials, Health Canada confirms that despite the Moderna bivalent targeting BA.1, it also has a “stronger immune response” against BA.4/BA.5, compared to the original shots.
With cases of Omicron subvariants rising, health officials, including Canada’s Chief Public Health Officer, Dr. Theresa Tam, are urging Canadians to get these new shots.
“I am concerned. From what I’m hearing from the experts...the coming months will be critical when it comes to COVID-19 infection and all the consequences this can have for people and health-care workers who are already quite tired,” said federal Health Minister Jean-Yves Duclos.
Deputy federal chief Public Health Officer Dr. Howard Njoo said that he believes Canada has ordered enough bivalent shots to go around, promising that deliveries of Pfizer’s bivalent shots would begin in a matter of days. 10.5 million doses of the Moderna had been delivered, with shipments of the Pfizer shots also beginning to arrive in Canada.
BC has received 1.4 million of the 10.5 million in Canada. British Columbians aged 18 and older or part of a vulnerable population will be of fered a bivalent vaccine this fall. The Pfizer bivalent is becoming available for those aged 12 and older. The province has received 1.7 million doses, according to BC’s provincial health officer, Dr. Bonnie Henry, and Health Minister Adrian Dix.
Generally, experts recommend getting a booster three to six months after a COVID infection or vaccination to maximize its efficacy, depending on medical and social risk factors. So far, just half of Canadians have gotten boosted, with most people getting their first two shots in spring and summer 2021. Bivalent vaccines are only available as boosters, and older vaccines are being phased out.
This is just the beginning of what mRNA can do. Research in its very early stages is underway looking at its uses in fighting zika, influenza, malaria, and, notably, cancer.
Leading this effort is BioN-Tech, a partner with Pfizer in making COVID vaccines. Özlem Türeci, Chief Medical Officer of BioN-Tech, told The Atlantic magazine they’ve had “a number of breakthroughs” in mRNA treatments for bowel cancer, melanoma and other tumour types.
“I’m fully convinced that now, even more than ever before, that mRNA can be broadly transformational.” Türeci stated in his interview with The Atlantic.