Doctors’ message for anyone worried by blood clot news: ‘They’re good vaccines’

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    TORONTO, Ontario (CTV Network) — In the wake of the first reported blood clot in Canada linked to the AstraZeneca vaccine, many doctors are emphasizing that undergoing the risk of an exceedingly rare adverse response to a vaccine is far more safe than risking contracting COVID-19 during Canada’s devastating third wave.

“The vast majority of people that get this vaccine have a very easy time with it and have significant protection against COVID-19,” Dr. Isaac Bogoch, an infectious disease specialist, told CTV News Channel on Tuesday.

“If people have this vaccine that’s available to them, it’s a wonderful idea to get it, because it will work, it does protect you against COVID-19.”

In Canada, more than 700,000 people have received the AstraZeneca vaccine. But concerns over the rare chance of developing serious blood clotting after receiving the vaccine have caused some to avoid the vaccine, or express fears about taking it.

The hesitancy could be a roadblock to Canada’s goal to vaccinate the population as quickly as possible in order to help fight a third wave that grows every day. At the end of March, Canada received 1.5 million doses of the Oxford-AstraZeneca vaccine from the United States, a small fraction of the 20 million doses expected in the coming weeks and months.

“We’ve watched this [vaccine] transform the epidemic in countries like the United Kingdom, and it can transform the epidemic here in Canada as well,” Bogoch said.

Dr. Aileen Marty, an infectious disease specialist and outbreak response expert, echoed the sentiments, telling CTV News Channel that AstraZeneca poses far less of a risk than COVID-19.

“The virus is far, far worse, and its risk and its long-term complications are far, far worse than any risk from any vaccine,” she said.

Among the experts advising not to avoid AstraZeneca is Ishac Nazy, an associate professor of medicine at McMaster University and director of the McMaster Platelet Immunology Laboratory — the very same lab that identified Tuesday’s case of a Canadian patient developing a blood clot linked to AstraZeneca.

“The benefits of getting vaccinated […] far outweigh the risks of the clotting events that are induced by the vaccine,” he told CTV News.

It is far more likely that a person will die from blood clots that occurred as a result of becoming severely ill with COVID-19, he explained, than a person dying from blood clots as a result of a vaccine.

“People should go and get their vaccine, because the chances of getting a clot from the vaccine [are] very rare.”

Read more: Canada closely watching U.S. pause of J&J COVID-19 vaccine over rare blood clots
Bogoch pointed out that we still don’t know exactly how often it is that blood clots develop in connection to receiving a vaccine, because the numbers are still too low to make a proper estimate.

According to the World Health Organization, this rare blood clot — called vaccine-induced prothrombotic immune thrombocytopenia (VIPIT) — occurs in just one in a million doses administered. Another report from Germany suggested numbers could be closer to one in 100,000.

So far, in Canada, we’ve had one case in around 700,000, but that number could get larger or smaller as more doses are administered and we learn more.

“It’s still very likely to be an extremely rare event, and that has to be factored in with the enormous benefit that this vaccine offers, not at just an individual level, but also at a population level,” Bogoch said.

When we weigh these rare adverse events with things such as the rate of COVID-19 currently circulating in Canada, as well as ICU capacity and the health risks that come with contracting COVID-19, the “scale tips” in the favour of getting vaccines like AstraZeneca, he said.

“They’re good vaccines, and they really do the job.”

Experts are not dismissing the seriousness of these adverse response to the vaccine. They just want to make it clear that the rarity of them makes this vaccine still safe and beneficial to the overall population.

“You can never brush under the rug any potential adverse event, no matter how rare it is,” Bogoch said. “It’s a type of blood clot that it is indeed on the more severe end of the spectrum, you can’t ignore that. But it is a very, very rare event.”

Read more: The AstraZeneca vaccine, blood clots and VIPIT: What you need to know
Marty said the important thing now is to investigate further and discover the mechanisms behind these blood clots.

“We need to find out exactly why it happened in these particular [people],” she said.

If it can be determined if certain people are more susceptible to them, and why, then those people can be directed to receive other vaccines instead.

Already, officials in Canada are taking steps with the information they have. The National Advisory Committee on Immunization changed its recommendations at the end of March to advise that only those over the age of 55 receive the AstraZeneca vaccine in response to reports that those who are younger might be more likely to experience blood clots.

Bogoch called this the “right thing” to do.

Meanwhile, at the McMaster laboratory tracking these adverse responses, Nazy believes their ability to identify cases connected to the AstraZeneca vaccine will contribute to the overall safety of the population, as they’ll be able to inform the public if the chances of developing these blood clots suddenly increases or not.

“Tracking the number of clotting events from AstraZeneca keeps us informed as [to] how high the risk could be if more clots start developing,” he said.

“We were very quick to actually start a national surveillance system across the country,” he added, explaining that doctors who suspect a patient has blood clots due to the vaccine are able to send samples to the McMaster lab, where they can be given a special screening test.

“Here at McMaster, we are able to diagnosis patients in a timely and accurate fashion and report back directly to the doctors.”

The faster that happens, the faster patients can be treated.

“The most important thing is we can actually, now we know about it, we can actually recognize it, diagnose it and very quickly, treat it,” Nazy said. “And once we do that, the patient will be quickly to recovery.”

These blood clots can be deadly; last week, a man in the U.K. died due to a blood clot thought to be connected to the vaccine.

But the Canadian patient identified by the McMaster lab on Tuesday has received treatment, according to the Quebec health ministry, and is recovering at home.

It’s a side-effect that experts are continuing to research, all with the goal of minimizing the risk. In the meantime, doctors and experts are sticking to the same message: get vaccinated.

“Currently, in Canada, we are in the middle of a very, very tough third wave, there’s a ton of COVID circulating in our communities, there are vaccines that are available, that work, that are safe, that are effective,” Bogoch said. “Of course, there are potential rare, rare side-effects, like this type of blood clot, but again, it has to be contextualized.”

Nazy said the “message to Canadians is we’ve got a very good system to recognize diagnose and treat these events.

“They are very rare, we understand that they’re serious, but getting vaccinated is probably more important.”

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