Why isn't Canada getting the same COVID-19 booster as the U.S.? Here's what B.C. officials say about bivalent vaccines

An updated COVID-19 vaccine is coming to B.C. for a fall booster program and local health officials explained Tuesday how the new combination will offer improved protection from the disease.

Dr. Bonnie Henry, Health Minister Adrian Dix and Dr. Penny Ballem, who is in charge of the province's vaccine rollout, gave the joint update just days after Health Canada approved Moderna's Omicron-targeting bivalent shot.

The vaccine is scheduled to arrive in B.C. this week, with hundreds of thousands of doses expected as the booster campaign ramps up.

WHAT IS A BIVALENT VACCINE?

The newest COVID-19 vaccine is a bivalent vaccine, meaning it combines two types of vaccine. Included in the one approved by Health Canada is a vaccine that targets the original COVID-19 strain along with a second that targets the Omicron variant, specifically the BA.1 subvariant.

"These types of combination vaccines are actually very common," Henry said. "The most common one that people probably know very well are influenza vaccines."

In fact, the annual influenza shot often has three or four combinations of vaccine to target different strains of the virus.

Officials said the new COVID-19 vaccine will offer improved protection against Omicron, which is the most common variant in B.C. right now.

WHY ISN'T B.C. GETTING THE SAME VACCINE AS THE U.S.?

In the U.S., a slightly different booster was approved by the Food and Drug Administration.

That vaccine targets BA.4 and BA.5 subvariants of Omicron, which are believed to account for the majority of new cases in many regions, including B.C.

Health officials explained, however, that data from clinical trials on Canada's bivalent vaccines shows it offers a boost of protection from all subvariants of Omicron.

"Clinical studies have show that BA.1 component of the bivalent vaccine stimulates a very strong immune boost against all of the Omicron strains, including BA.4/5. So that's important," Henry said.

"It’s not a dramatically different strain. It's not a new variant, it's not a variant of concern. It's still within that Omicron and so we're seeing good protection."

As well, there is limited data on the effectiveness of the newest bivalent vaccine in comparison to the version Canada's receiving.

Officials explained waiting for more data on the newest bivalent vaccine would've led to a delay in rolling out the updated booster in Canada, which could be problematic heading into the fall respiratory season when cases may rise.