VANCOUVER -- B.C. announced its full COVID-19 vaccine distribution plan through September on Friday, and while it relies on regular shipments of both Pfizer and Moderna vaccines, officials are looking into the safety of mixing doses between the two.

Dr. Bonnie Henry explained during a morning news conference about vaccine rollout that discussions have been ongoing across the country, especially after a recent delay in Pfizer shipments.  

The top doctor said Canadian health officials are in contact with their counterparts in the U.K., where some second doses of the vaccine are being delayed by as much as three months. 

"We're trying to understand the impact that has on effectiveness of the vaccine," she said.

Henry said there has been "some permissive language" around using the same type of vaccine. In other words, she explained, because both Moderna and Pfizer are mRNA vaccines, there's a better chance they could be interchangeable. 

"But that is a last resort. It's only if the original vaccine is not available," she said. "We're still looking at the best advice on that and whether it's better to delay the second dose for longer or to provide the second dose with the alternate product."

One example scenario Henry gave is if an individual is at the 42-day mark after receiving their first Pfizer dose but there is no longer any Pfizer vaccine available, health officials are discussing what they would do in that instance. 

"We would have to make a decision about whether we use available doses of Moderna or whether we extend and wait for Pfizer to become available. So that's the situation we're not yet in, but that we may be facing," she said. 

"Right now we don't have good information to inform one or the other of those decisions."

Henry said there is little data on the matter right now, but added there's been weekly discussions on the topic with the National Advisory Committee on Immunization, with another call planned for this weekend.