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Danuta Skowronski was poring over Pfizer-BioNTech vaccine data on a Friday night in mid-December when she had an “aha!” moment.
The epidemiology lead at the British Columbia Centre for Disease Control realized she could actually “correct” the data Pfizer had submitted to the U.S. Food and Drug Administration on the effectiveness of just one dose of its vaccine.
In clinical trials, Pfizer couldn’t accurately determine the efficacy of a single shot because participants had already received their second dose after three weeks, and there was no comparative one-dose study done.
Pfizer reported an efficacy of 52 per cent for one shot, compared to the more commonly cited 95 per cent after the second.
But Skowronski, who has been working on vaccine effectiveness analyses for more than 15 years, realized the company had included in its analysis the two-week time period immediately after vaccination — before the body’s immune response typically kicks in.
Dr. Danuta Skowronski with the B.C. Centre for Disease Control is in favour of delaying second doses to four months after analyzing the data Pfizer submitted to the U.S. Food and Drug Administration. (Harman/CBC)
She told CBC News vaccines are never expected to protect “instantaneously,” and that there is always a “grace period” of a couple of weeks that factors into vaccine effectiveness.
“What we found was that they were underestimating the efficacy of the first dose, and rather than the efficacy being 52 per cent, it was actually 92 per cent, ” she said. “For us, that was a game changer.”
Canada is now an outlier in the global vaccination rollout. No other country in the world has delayed second doses up to four months, and there is no evidence yet on the long-term effect it could have on immunity to COVID-19.
Some scientists say we are venturing into uncharted waters. Others are comfortable with the risk.
Why is Canada delaying second doses?
NACI says if second doses are stretched to four months across the country starting this month, close to 80 per cent of Canadians over 16 could get at least one shot of the Pfizer-BioNTech or Moderna vaccine by the end of June.
But Canada’s chief science adviser, Mona Nemer, says the decision to delay doses amounted to a “population level experiment.”
“The comment from the chief science adviser was most unfortunate,” said Skowronski. “It did not reflect the careful risk-benefit analysis that went into this decision, and frankly, that is a science and an art to be able to do that.”
But aside from a vague reference to “real-world effectiveness” from Canada and other countries in NACI’s recommendations, little evidence has been communicated to Canadians to convince them that the change in vaccine rollout strategy is the right move.
NACI says its decision to delay second doses is based on emerging real-world data from Quebec, B.C., Israel, the U.K. and the U.S. that showed “good effectiveness” of between 70 and 80 per cent from a single dose of the vaccines “for up to two months in some studies.”
But it also makes clear that these studies haven’t yet collected four months of data on the long-term effectiveness of a single dose, meaning NACI is betting on the “high levels of protection” shown so far.
“It’s shown us really good vaccine effectiveness two months after receipt of the first dose and that the effectiveness isn’t decreasing over time,” Dr. Shelley Deeks, vice-chair of NACI and a lead author of the recommendations, said in an interview.
“After looking at it from all of these angles, and given that we are in a situation of limited supply, the committee came to a strong consensus that we recommend the interval to be extended to four months.”
Deeks said NACI will continue monitoring vaccine effectiveness data as it comes out around the world to determine if it needs to further alter its recommendations — meaning another change to Canada’s vaccine rollout strategy is possible.
“If we need to reassess and revise the recommendations, we will,” she said. “But this will allow more Canadians to receive the first dose and have a vaccine in a more timely manner and will have an impact on serious disease.”
‘Not based on evidence’
The move has effectively doubled Canada’s doses of COVID-19 vaccines overnight, but some scientists are critical of the move to experiment with delaying intervals.
“The decision is not based on evidence. It’s really based on an extrapolation of the evidence,” said Brad Wouters, executive vice-president of science and research at the University Health Network in Toronto.
“We’ve only been giving this vaccine for two months, so we don’t have data out to four months — no one in the world has been waiting four months for a second dose.”
WATCH | The science behind delaying the 2nd dose of COVID-19 vaccines:
Federal government scientists have put their support behind delayed second doses of COVID-19 vaccines — which several provinces were already doing — and ongoing research shows some of the benefits of the adapted strategy. 2:04
Wouters says it’s unclear if the delay will impact the effectiveness of the second dose, and the decision comes with a lot of uncertainty in the months ahead.
Skowronski says once good protection is established, it doesn’t suddenly disappear or “fall of a cliff.” Instead, protection against a disease wanes gradually after a vaccination, which buys researchers time to “re-evaluate the optimal timing of the second dose.”
She said that longer intervals between a first and a second dose of a vaccine are generally preferred because shorter intervals can interfere with the immune boost response and longer intervals are often associated with ultimately higher antibody levels.
Alyson Kelvin, an assistant professor at Dalhousie University in Halifax and virologist at the Canadian Center for Vaccinology, says the clinical trials on COVID-19 vaccines ran with the shortest time frame possible so they could get data out quickly, but previous studies on other vaccines show longer intervals are generally better.
Skowronski says it’s unclear why Pfizer went with a three-week interval for their clinical trials, but it may have been due to pressure to get the vaccine out or because they didn’t expect to have such good protection with the first dose.
“The only reason to go with a shorter interval is if you don’t get good protection with the first dose, and a second dose administered sooner could top it up a lot,” Skowronski said.
“That’s a scenario that we are not dealing with here. We’re getting excellent protection after the first dose, and we have a clear and present danger threat now with ongoing elevated pandemic disease risk on top of that scarcity of vaccine supply.”
Lack of clear communication for Canadians
While Skowronski is confident delaying the second dose is the right move for Canada, she and other experts feel the communication to Canadians from NACI on the decision could have been more clear.
She said it’s important to stress to Canadians that they still need a second dose eventually to have as much protection from COVID-19 as possible and that they should take any vaccine offered to them to combat its spread.
WATCH | The evidence is there for the ‘concept of further delay’ of second doses: Dr. Naylor:
Dr. David Naylor, Co-Chair of the COVID-19 Immunity Task Force, joined Power & Politics Wednesday to discuss the National Advisory Committee on Immunization’s new recommendation that second doses of COVID-19 vaccines can be administered up to four months after the first dose. 2:33
Dr. David Naylor, who co-chairs the federal government’s COVID-19 immunity task force, said the decision to delay doses is “defensible,” but agreed the decision could have been explained much more clearly to Canadians.
“There didn’t seem to be an organized communications strategy overall,” he said.
“The unhappy result is that a decision which might have been welcomed as a wider tide lifting many more boats and helping us end the epidemic more quickly has instead caused a real undercurrent of anxiety. I hope that subsequent communications will clear the air.”
Wouters says he worries about how Canadians will interpret the move to delay doses given the limited understanding the average person might have on the issue.
“There wasn’t a lot of information about why the decision was made, what the evidence was, what the process was,” he said. “There could certainly be a lot more transparency around the process and how that was done.”
Lisbeth Mendez comforts Luigini Parravano outside the Richmond Green Sports Centre, in Richmond Hill, Ont., on Monday. Parravano, along with her husband, Mario, were among the first cohort of senior citizens aged 80+ in York Region’s mass COVID-19 vaccination program. (Evan Mitsui/CBC)
Dr. Allison McGeer, a medical microbiologist and infectious disease specialist at Toronto’s Mount Sinai Hospital, says there is “overwhelming” evidence in favour of second doses.
“People who haven’t spent time in vaccination and thinking about vaccination are always really anxious about the stuff you don’t know in the future with vaccines,” she said.
“I’m comfortable with those uncertainties, and with the fact that we can deal with them when we get there. But if you’re not comfortable with that, there is a tendency to really worry about the potential consequences of doing that.”
Skowronski says Canadians should expect health experts to adapt to and absorb emerging evidence as it becomes available and incorporate that into recommendations.
“You don’t do business as usual in the midst of a crisis,” she said. “You don’t want experts that are holding steadfast to an earlier opinion or viewpoint while knowledge has amassed and moved on.
“You want your experts keeping pace with those developments and making decisions based on what is known as time evolves, especially during a dynamic crisis like an unfolding pandemic.”
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VANCOUVER – Contract negotiations resume today in Vancouver in a labour dispute that has paralyzed container cargo shipping at British Columbia’s ports since Monday.
The BC Maritime Employers Association and International Longshore and Warehouse Union Local 514 are scheduled to meet for the next three days in mediated talks to try to break a deadlock in negotiations.
The union, which represents more than 700 longshore supervisors at ports, including Vancouver, Prince Rupert and Nanaimo, has been without a contract since March last year.
The latest talks come after employers locked out workers in response to what it said was “strike activity” by union members.
The start of the lockout was then followed by several days of no engagement between the two parties, prompting federal Labour Minister Steven MacKinnon to speak with leaders on both sides, asking them to restart talks.
MacKinnon had said that the talks were “progressing at an insufficient pace, indicating a concerning absence of urgency from the parties involved” — a sentiment echoed by several business groups across Canada.
In a joint letter, more than 100 organizations, including the Canadian Chamber of Commerce, Business Council of Canada and associations representing industries from automotive and fertilizer to retail and mining, urged the government to do whatever it takes to end the work stoppage.
“While we acknowledge efforts to continue with mediation, parties have not been able to come to a negotiated agreement,” the letter says. “So, the federal government must take decisive action, using every tool at its disposal to resolve this dispute and limit the damage caused by this disruption.
“We simply cannot afford to once again put Canadian businesses at risk, which in turn puts Canadian livelihoods at risk.”
In the meantime, the union says it has filed a complaint to the Canada Industrial Relations Board against the employers, alleging the association threatened to pull existing conditions out of the last contract in direct contact with its members.
“The BCMEA is trying to undermine the union by attempting to turn members against its democratically elected leadership and bargaining committee — despite the fact that the BCMEA knows full well we received a 96 per cent mandate to take job action if needed,” union president Frank Morena said in a statement.
The employers have responded by calling the complaint “another meritless claim,” adding the final offer to the union that includes a 19.2 per cent wage increase over a four-year term remains on the table.
“The final offer has been on the table for over a week and represents a fair and balanced proposal for employees, and if accepted would end this dispute,” the employers’ statement says. “The offer does not require any concessions from the union.”
The union says the offer does not address the key issue of staffing requirement at the terminals as the port introduces more automation to cargo loading and unloading, which could potentially require fewer workers to operate than older systems.
The Port of Vancouver is the largest in Canada and has seen a number of labour disruptions, including two instances involving the rail and grain storage sectors earlier this year.
A 13-day strike by another group of workers at the port last year resulted in the disruption of a significant amount of shipping and trade.
This report by The Canadian Press was first published Nov. 9, 2024.
The Royal Canadian Legion says a new partnership with e-commerce giant Amazon is helping boost its veterans’ fund, and will hopefully expand its donor base in the digital world.
Since the Oct. 25 launch of its Amazon.ca storefront, the legion says it has received nearly 10,000 orders for poppies.
Online shoppers can order lapel poppies on Amazon in exchange for donations or buy items such as “We Remember” lawn signs, Remembrance Day pins and other accessories, with all proceeds going to the legion’s Poppy Trust Fund for Canadian veterans and their families.
Nujma Bond, the legion’s national spokesperson, said the organization sees this move as keeping up with modern purchasing habits.
“As the world around us evolves we have been looking at different ways to distribute poppies and to make it easier for people to access them,” she said in an interview.
“This is definitely a way to reach a wider number of Canadians of all ages. And certainly younger Canadians are much more active on the web, on social media in general, so we’re also engaging in that way.”
Al Plume, a member of a legion branch in Trenton, Ont., said the online store can also help with outreach to veterans who are far from home.
“For veterans that are overseas and are away, (or) can’t get to a store they can order them online, it’s Amazon.” Plume said.
Plume spent 35 years in the military with the Royal Engineers, and retired eight years ago. He said making sure veterans are looked after is his passion.
“I’ve seen the struggles that our veterans have had with Veterans Affairs … and that’s why I got involved, with making sure that the people get to them and help the veterans with their paperwork.”
But the message about the Amazon storefront didn’t appear to reach all of the legion’s locations, with volunteers at Branch 179 on Vancouver’s Commercial Drive saying they hadn’t heard about the online push.
Holly Paddon, the branch’s poppy campaign co-ordinator and bartender, said the Amazon partnership never came up in meetings with other legion volunteers and officials.
“I work at the legion, I work with the Vancouver poppy office and I go to the meetings for the Vancouver poppy campaign — which includes all the legions in Vancouver — and not once has this been mentioned,” she said.
Paddon said the initiative is a great idea, but she would like to have known more about it.
The legion also sells a larger collection of items at poppystore.ca.
This report by The Canadian Press was first published Nov. 9, 2024.
