Patients, health care workers need to be on alert for AstraZeneca-related COVID-19 vaccine illness: experts

Lisa Stonehouse had aches and pains after she received her first dose of the Oxford-AstraZeneca vaccine, but after about a week, things took a turn. She developed a headache that quickly got worse – so bad that her 19-year-old daughter insisted they head to the emergency department to get it checked out.

Ms. Stonehouse’s daughter, Jordan, waited in the car outside Grey Nuns Community Hospital in Edmonton for what she thought would be an hours-long visit. Ms. Stonehouse returned less than 10 minutes later, said long-time family friend Wilf Lowenberg.

“She said, ‘Well, they sent me away. They said there’s nothing they can do for me. Take some Tylenol, and go to bed,’” Mr. Lowenberg said.

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By the next morning, Ms. Stonehouse was in so much pain she couldn’t get out of bed, Mr. Lowenberg said. She was taken to another hospital, where a CT scan confirmed a blood clot, and she was rushed to the University of Alberta Hospital but suffered a seizure on the way.

She died three days later, becoming one of three people in Canada who have died from extremely rare but serious blood clots linked to the AstraZeneca vaccine. Covenant Health, the Catholic health authority that runs the hospital, is investigating.

Experts say Ms. Stonehouse’s case underscores the importance of ensuring patients and front-line health workers know how to identify such blood clots, caused by a condition known as vaccine-induced immune thrombotic thrombocytopenia, or VITT, and how to treat them.

Most provinces have stopped administering AstraZeneca vaccines for first doses and supplies are running low in other provinces, which will mean far fewer Canadians will have access to that vaccine. But more than two million doses have already been distributed and many of the people who’ve received them are still in the four- to 28-day window when the blood clots can appear. The federal government continues to pursue additional doses of that vaccine.

Menaka Pai, a hematologist at Hamilton Health Sciences and an assistant professor at McMaster University, said the emergence of VITT is part of a broader “information overload” that both patients and health care staff have been coping with throughout the pandemic. Most doctors who encounter a patient with a suspected case of VITT will not have seen it before.

“It’s a huge and understandable gap that needs to be filled, given the newness and the way the information is evolving,” said Dr. Pai, who stressed that she did not know what happened in the Edmonton case and was speaking generally.

Alberta has had one other case in which a clot was identified, treated and the patient survived. Across the country, there were at least 18 confirmed cases of VITT, including three deaths, as of Wednesday and 10 more under investigation.

In Alberta, which was the first of several provinces to stop using the AstraZeneca vaccine for first doses, patients who had the shot received a printout that detailed the potential symptoms with a warning to seek medical attention immediately if they occurred. It’s a long list that includes severe headaches, shortness of breath, chest and stomach pain and blurry vision, among others, and depend on where in the body the blood clots form.

Dr. Pai said it’s a long list of symptoms that have a range of other causes, many of them far less serious than VITT.

“These are very vague symptoms. Depending on where the clotting is at its worst, you’re going to get entirely different symptoms,” she said. “What we’re telling people is, ‘Here’s the laundry list. Now how do we empower you?’ These symptoms [of VITT] are new, they’re different, they’re severe.”

Provincial health authorities and researchers are also distributing information for doctors about how to diagnose VITT. Ontario’s COVID-19 Science Advisory Table, for example, has published guides for health care workers.

Dr. Pai said some people should still consider getting a first dose of AstraZeneca where available, even with the risks – for example, if they work somewhere that puts them at high risk for catching COVID-19 and still face a long wait for an mRNA vaccine from Pfizer or Moderna. It’s a “very personal” decision to weigh those risks, she said.

Michael Hill, who teaches at the University of Calgary’s medical school and specializes in strokes, said VITT is now relatively straightforward to diagnose using tools such as a CT scan and blood tests to measure platelet levels. The clots are treated using blood thinners.

But he said first doctors need to identify VITT as a possibility to ensure it is investigated.

“This is a challenging thing, even in the routine setting,” said Dr. Hill, referring to diagnosing blood clots in the brain. “You do have to think of it in order to make the diagnosis. Unfortunately, the initial symptoms are non-specific.”

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