Dr. Bonnie Henry talks about phase two in B.C.’s COVID-19 immunization plan as Premier John Horgan and Minister Arian Dix look on during a press conference at Legislature in Victoria, B.C., on Monday, March 1, 2021. THE CANADIAN PRESS/Chad Hipolito

Dr. Bonnie Henry talks about phase two in B.C.’s COVID-19 immunization plan as Premier John Horgan and Minister Arian Dix look on during a press conference at Legislature in Victoria, B.C., on Monday, March 1, 2021. THE CANADIAN PRESS/Chad Hipolito

Vaccines: B.C. pushes ahead with delayed second doses as Ontario waits for national guidance

Dr. Bonnie Henry said she expects the national immunization committee to align with the province’s decision

Ontario is waiting for a recommendation from the National Advisory Committee on Immunization before delaying second doses of COVID-19 vaccines, while British Columbia is pushing ahead with its plan to extend the interval to four months.

A researcher whose work underpinned B.C.’s decision said Tuesday that the change was based on strong data. Dr. Danuta Skowronski, epidemiology lead of influenza and emerging respiratory pathogens at the B.C. Centre for Disease Control, said Pfizer-BioNTech underestimated the efficacy of the first dose of its own vaccine in its submissions to the U.S. Food and Drug Administration.

Skowronski said the company included data from the first two weeks after trial participants received the shot, which is a time when vaccines typically aren’t effective. When she and her colleagues adjusted the data, they made a surprising discovery.

“We took that into account and showed that the vaccine efficacy was not 52 per cent, it was actually 92 per cent. That was actually very similar, that first-dose efficacy, to what the other manufacturer, Moderna, had actually itself correctly analyzed in its own submissions to the FDA,” she said in an interview.

Skowronski said the four-month interval is based on the basic principles of vaccine science. The protection from a first dose of vaccine does not suddenly disappear, it gradually wanes over time, and scientists are typically more concerned about providing a second dose too soon rather than too late, she said.

“I think if the public had a chance to hear and to understand that, they would say, ‘OK, this is not messing around. This is really managing risk in a way that maximizes protection to as many Canadians as possible.’”

She said the province’s decision was backed up by data from Quebec, the United Kingdom and Israel, and comes at a time when B.C. residents are experiencing severe social and economic effects from isolation during the pandemic.

Skowronski added that the B.C. Centre for Disease Control also examined the effects of a single dose on long-term care residents and health-care workers in the province and found that it reduced the risk of the virus by 80 per cent within two to three weeks.

Provincial health officer Dr. Bonnie Henry has said she expects a statement from the national immunization committee aligning with the province’s decision, while Ontario Health Minister Christine Elliott said Tuesday she wanted to wait for such a recommendation.

She said extending the interval between doses would allow the province to get some level of protection to more people.

“This would be a considerable change,” she said.

“With the variants of concern out there, this could make a significant difference for Ontario in reducing hospitalizations and deaths. So, we are anxiously awaiting NACI’s review of this to determine what they have to say in their recommendations.”

Dr. Shelley Deeks, vice-chair of the national committee, said in an email the group is expected to issue a statement on extending the dose interval on Wednesday, but she did not confirm it would align with B.C.’s plan.

Alberto Martin, a University of Toronto immunology professor, said his understanding of a published Pfizer-BioNTech clinical trial was that the first dose provided 60 per cent protection and the second dose provided 95 per cent protection.

He said there is “obviously some concern” about B.C.’s plan because he is not aware of any clinical trial that examined a four-month gap between doses.

“There might be a risk that you’re not going to achieve that 95 per cent protection that the Pfizer-BioNTech vaccine can achieve with two doses separated by a few weeks apart,” he said.

However, he said difficult times — when the vaccine supply is so limited — require drastic measures.

“I think what they’re trying to do is immunize as many people as possible, get partial protection in the population and then hope for the best that the second dose that comes in four months later will boost the immune response enough to achieve that 95 per cent protection,” he said.

“It’s a difficult decision to make. I don’t know whether I’d like to be in that position, but I think it’s understandable why they’re doing this.”

Coronavirus

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

In a feature article published April 10, 2021 in The Times of London, ‘headlined British Columbia has what it takes to rival Napa Valley,’ the valley is praised extensively for its natural beauty and wine. (File photo)
From the U.K. with love: Okanagan wine, scenery receives international praise

The Times of London newspaper recently featured the valley in a wine and travel piece

The future of the Eagle Pass Lookout cabin is being discussed. (File photo)
Options presented for future of former Eagle Pass fire lookout in Shuswap

Stakeholders met in 2020 to discuss the restoration, or possible removal of the cabin

FILE — In this March 31, 2021 file photo, a nurse fills a syringe with a dose of the Johnson & Johnson’s one-dose COVID-19 vaccine at the Vaxmobile, at the Uniondale Hempstead Senior Center, in Uniondale, N.Y. The U.S. is recommending a “pause” in administration of the single-dose Johnson & Johnson COVID-19 vaccine to investigate reports of potentially dangerous blood clots. In a joint statement Tuesday, the Centers for Disease Control and Prevention and the Food and Drug Administration said it was investigating clots in six women in the days after vaccination, in combination with reduced platelet counts. (AP Photo/Mary Altaffer, File)
72 new COVID-19 cases in Interior Health

This brings the total number of cases in the region to 9,666 since the pandemic began

The Literacy Alliance of the Shuswap Society will be expanding its offerings to seniors this year and hopes to return its Cyber Seniors program when one-to-one training is once again allowed. (Photo contributed)
Shuswap organization aims to help seniors become more cyber savvy

BC Hydro report finds seniors reluctant to use

The Salmon Arm RCMP are investigating a Saturday, April 10 gathering at Blackburn Park for provincial health order violations. (Jim Elliot/Salmon Arm Observer)
Salmon Arm RCMP investigating Blackburn Park rally

Police say more than 200 people in attendance

Restaurant patrons enjoy the weather on a patio in Vancouver, B.C., Monday, April 5, 2021. The province has restricted indoor dining at all restaurants in B.C. due to a spike in COVID-19 numbers. THE CANADIAN PRESS/Jonathan Hayward
B.C.’s COVID-19 indoor dining, drinking ban extending into May

Restaurant association says patio rules to be clarified

A dumpster was on fire behind a residential complex in downtown Penticton Tuesday afternoon. (Brennan Phillips Western News)
Dumpster fire extinguished in downtown Penticton

There has been a string of dumpster fires lately

Skogie’s Express Tunnel Wash on Anderson Way in Vernon. (Submitted photo)
Lawsuit dismissed after vehicle damaged while inside Okanagan car wash

Civil Resolution Tribunal dismisses driver’s claim following a collision inside Skogie’s car wash in Vernon

(Mayor Cindy Fortin - Peachland)
Peachland mayor declines early vaccination offer

Mayor Cindy Fortin said she wants seniors, immunocompromised individuals to get the shot first

B.C. Premier John Horgan speaks at the B.C. legislature. (B.C. government)
Tougher COVID-19 restrictions in B.C., including travel, still ‘on the table’: Horgan

John Horgan says travel restrictions will be discussed Wednesday by the provincial cabinet

NorKam secondary student Karis Wilson in the outfit that got her sent home from school on Feb. 23, 2021. (Kamloops This Week photo)
Clothing that ‘detracts from learning process’ removed from SD73 student dress code

Policy change underway after student in knee-length dress, long-sleeve turtleneck sent home

Conservation officers caught three men over fishing bull trout in Kinbasket Lake. (Facebook)
B.C. men fined $1.7K for overfishing near Revelstoke, Golden

The seized fish were donated to the Golden Food Bank

A shop up on Grand Oro Road near Twin Lakes burned down on Monday. (Facebook)
Fire rips through shop in small South Okanagan town

The building was destroyed despite community efforts to fight the fire

WATCH: Conservation group releases short doc on saving South Okanagan’s ‘precious’ Sickle Point

Sickle Point, the last intact wetland near Skaha Lake, is facing the prospect of development

Most Read