As coronavirus vaccines make it into the arms of more Canadians every day, experts say it’s understandable that news of potential adverse reactions piques a certain amount of interest.
But there’s a difference between “adverse events following immunization” and adverse events “directly related to a vaccine,” said Alyson Kelvin, a virologist and assistant professor at Dalhousie University, who is currently working on COVID-19 vaccines with VIDO-InterVac.
This is an important distinction, she said, particularly as we begin to question new reports like the deaths of elderly vaccine recipients in Norway.
“I could get the vaccine and five hours later get hit by a car, and that’s going to be recorded as an adverse event,” she said.
“Just because it’s an adverse event, doesn’t mean it’s directly related to the vaccine. It just means that it happened after someone got a vaccination… In Norway’s case, we’re talking about adverse events following immunization.”
Deaths in Norway
While it’s far from unusual that new drugs, like the COVID-19 vaccine, come with side effects and potential safety concerns, the reports of over 30 deaths among elderly people in Norway have stirred worry.
But at this point, there’s little reason to be concerned, experts agree.
Norway has prioritized the immunization of nursing-home residents, including those with serious underlying diseases. Of the about 45,000 people vaccinated with the Pfizer-BioNTech shot since mid-January, 33 deaths have been reported.
Those who died were aged 75 years and older, according to Norwegian health authorities. All were described as elderly, frail, with serious diseases and nearing the end of their lives independent of the vaccine.
“We have to look at the collective global experience,” said Isaac Bogoch, an infectious disease specialist based out of Toronto General Hospital.
“There have been over 40 million doses administered globally, mostly to older populations, including those in long-term care. We haven’t heard those signals emerge from Canada, the United States, or the U.K. — all places that have formal mechanisms for evaluating adverse events.”
Norwegian officials say there’s no evidence of a direct link between the vaccines and the deaths, but they are still investigating. However, they did provide some context, telling reporters Monday that an average of 400 people die every week in Norway’s nursing homes and long-term care facilities.
“It’s grim to speak about but we are vaccinating our oldest individuals who are not only more susceptible to COVID-19, they’re more susceptible to dying of any causes on a daily or weekly basis,” Kelvin said.
“But these things still need to be followed, even if they seem completely unrelated.”
She returned to her car accident analogy.
“Maybe someone drove up and hit me while I was standing on the corner, but maybe I was feeling lightheaded after getting the vaccine and it caused me to step in traffic,” she said.
“These are important links we need to be making.”
Adverse reaction reporting
Different countries have different mechanisms for determining adverse effects after vaccination.
How these events are reported and reviewed — and the sharing of that data globally — is paramount, Kelvin said.
Health Canada this month launched a new website that provides weekly reports on vaccine safety. It details how many people experience non-serious events, like soreness at the injection site, and serious events, like severe allergic reactions.
The deaths in Norway were reportedly associated with fever, nausea and diarrhea. While these sit on the more serious side of the spectrum, these outcomes would be minor to most.
It’s the adverse events of “special interest” that deserve particular attention, said Kelvin.
“These are actually related to the vaccine,” she said.
As of Jan. 8, there have been 24 adverse events related to COVID-19 vaccination in Canada, but zero adverse events of special interest.
“Meaning that even though 24 adverse events have been reported, none of them have been directly linked to a life-threatening adverse event following immunization, that’s related to the vaccine,” Kelvin said.
So far, there have been zero reported adverse events among Canada’s oldest demographic, categorized as 65-plus.
Since the vast majority of Canada’s first batch of vaccines are being doled out to long-term care facilities, Kelvin said this indicates no sign of an increased risk of adverse events in that age group.
“We’re not getting any type of safety signals here in Canada,” she said.
Of all the doses administered as of Jan. 8, a mere 0.007 per cent resulted in an adverse event. It’s a minuscule number, Kelvin said, “even though some of those might be completely unrelated to the vaccine.”
“It seems that we’re continuing a very strong safety profile,” she added.
Learning from Norway
Norway has no intention to change its recommendations on using the vaccine on the terminally ill. It will continue to vaccinate residents of care homes, including the frailest.
Pfizer told CNN on Saturday that it is working with the Norwegian Medicines Agency (NOMA) to gather all the relevant information, adding that NOMA has said that “the number of incidents so far is not alarming, and in line with expectations.”
The Public Health Agency of Canada did not respond to a request for comment on Norway’s reports by time of publication, however, there is no reason to believe Canada would consider changing its recommendation either, Kelvin said, pointing to the data.
However, Kelvin believes there’s value in investigating whether possible vaccine side effects could aggravate or exacerbate underlying illnesses, which was echoed by Steinar Madsen, the medical director at the Norwegian Medicines Agency.
He told Bloomberg this week that the side effects of immunization can, in some cases, “tip the patients into a more serious course of the underlying disease,” but emphasized that “COVID-19 is far more dangerous to most patients than vaccination.”
In the meantime, “emotion needs to be tempered with data and time,” said Bogoch.
“Do we see a signal amongst the noise of the millions and millions of doses administered? No, not really,” he said.
“Does that mean we don’t see that signal or that we aren’t looking for it? Of course not. We have to be open-minded about data that emerges but look at that data in an objective manner.”
— with files from Reuters and The Associated Press