B.C. has recorded its first case of a rare response to the AstraZeneca COVID-19 vaccine that causes blood clots.
Provincial health officer Dr. Bonnie Henry announced during a news conference on Thursday that the province had seen its first case of vaccine-induced immune thrombotic thrombocytopenia - or VITT.
The patient who developed the condition is a woman in her 40s, Henry said, adding that the patient is in stable condition and receiving treatment in hospital in the Vancouver Coastal Health region.
VITT happens after about one in every 100,000 doses of AstraZeneca, the provincial health officer said, noting that there is a test to determine if a person has developed the syndrome and there is treatment available.
"I recognize it can be alarming to hear of this blood clot," said Henry. "If you are somebody who's received this vaccine, you need to know that it is rare, and it is treatable, and you can be confident that you have received a safe and effective vaccine."
Henry encouraged anyone who has received any vaccine in B.C. and is experiencing significant side effects such as shortness of breath, persistent severe headache, chest or abdominal pain, or swelling in the limb to call 811 or consult their family doctor.
She acknowledged the anxiety some people may feel as a result of the rare possibility of VITT, and sought to reassure people who have received the AstraZeneca vaccine.
"Take a deep breath and be reassured that this is rare, that physicians know what to do, and that if you have any concerns that you can contact your health-care provider, you can go to the emergency department if it's severe, and also you can call 811, and we can get you assessed and treated if needed," Henry said.
VITT most often manifests between four and 28 days after receiving a first dose of the AstraZeneca vaccine, Henry said, noting that the woman who developed the condition in B.C. started experiencing symptoms on day five or six.
"She followed up with her family doctor, who recognized that this might be related and did a blood test," Henry said. "We've put out information to all physicians in British Columbia to remind them of the things to do, and the symptoms to look for."
The provincial health officer added that the process of detecting B.C.'s first case of VITT "happened as it should happen," and praised the woman and her physician for noticing the symptoms and getting a test done quickly.
She also stressed that the AstraZeneca vaccine is safe and effective.
"This is an excellent vaccine," Henry said. "We only need look at places like the U.K. to see how effective it is in preventing transmission, making sure that you are protected yourself, but also protecting your family and those that you are closest to."